diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/lguest/Makefile | 8 | ||||
| -rw-r--r-- | tools/lguest/lguest.c | 2016 |
2 files changed, 1684 insertions, 340 deletions
diff --git a/tools/lguest/Makefile b/tools/lguest/Makefile index 97bca4871ea3..a107b5e4da13 100644 --- a/tools/lguest/Makefile +++ b/tools/lguest/Makefile @@ -1,7 +1,13 @@ # This creates the demonstration utility "lguest" which runs a Linux guest. -CFLAGS:=-m32 -Wall -Wmissing-declarations -Wmissing-prototypes -O3 -U_FORTIFY_SOURCE +CFLAGS:=-m32 -Wall -Wmissing-declarations -Wmissing-prototypes -O3 -U_FORTIFY_SOURCE -Iinclude all: lguest +include/linux/virtio_types.h: ../../include/uapi/linux/virtio_types.h + mkdir -p include/linux 2>&1 || true + ln -sf ../../../../include/uapi/linux/virtio_types.h $@ + +lguest: include/linux/virtio_types.h + clean: rm -f lguest diff --git a/tools/lguest/lguest.c b/tools/lguest/lguest.c index 32cf2ce15d69..e44052483ed9 100644 --- a/tools/lguest/lguest.c +++ b/tools/lguest/lguest.c @@ -41,6 +41,8 @@ #include <signal.h> #include <pwd.h> #include <grp.h> +#include <sys/user.h> +#include <linux/pci_regs.h> #ifndef VIRTIO_F_ANY_LAYOUT #define VIRTIO_F_ANY_LAYOUT 27 @@ -61,12 +63,19 @@ typedef uint16_t u16; typedef uint8_t u8; /*:*/ -#include <linux/virtio_config.h> -#include <linux/virtio_net.h> -#include <linux/virtio_blk.h> -#include <linux/virtio_console.h> -#include <linux/virtio_rng.h> +#define VIRTIO_CONFIG_NO_LEGACY +#define VIRTIO_PCI_NO_LEGACY +#define VIRTIO_BLK_NO_LEGACY +#define VIRTIO_NET_NO_LEGACY + +/* Use in-kernel ones, which defines VIRTIO_F_VERSION_1 */ +#include "../../include/uapi/linux/virtio_config.h" +#include "../../include/uapi/linux/virtio_net.h" +#include "../../include/uapi/linux/virtio_blk.h" +#include "../../include/uapi/linux/virtio_console.h" +#include "../../include/uapi/linux/virtio_rng.h" #include <linux/virtio_ring.h> +#include "../../include/uapi/linux/virtio_pci.h" #include <asm/bootparam.h> #include "../../include/linux/lguest_launcher.h" @@ -91,13 +100,16 @@ static bool verbose; /* The pointer to the start of guest memory. */ static void *guest_base; /* The maximum guest physical address allowed, and maximum possible. */ -static unsigned long guest_limit, guest_max; +static unsigned long guest_limit, guest_max, guest_mmio; /* The /dev/lguest file descriptor. */ static int lguest_fd; /* a per-cpu variable indicating whose vcpu is currently running */ static unsigned int __thread cpu_id; +/* 5 bit device number in the PCI_CONFIG_ADDR => 32 only */ +#define MAX_PCI_DEVICES 32 + /* This is our list of devices. */ struct device_list { /* Counter to assign interrupt numbers. */ @@ -106,30 +118,50 @@ struct device_list { /* Counter to print out convenient device numbers. */ unsigned int device_num; - /* The descriptor page for the devices. */ - u8 *descpage; - - /* A single linked list of devices. */ - struct device *dev; - /* And a pointer to the last device for easy append. */ - struct device *lastdev; + /* PCI devices. */ + struct device *pci[MAX_PCI_DEVICES]; }; /* The list of Guest devices, based on command line arguments. */ static struct device_list devices; -/* The device structure describes a single device. */ -struct device { - /* The linked-list pointer. */ - struct device *next; +struct virtio_pci_cfg_cap { + struct virtio_pci_cap cap; + u32 pci_cfg_data; /* Data for BAR access. */ +}; - /* The device's descriptor, as mapped into the Guest. */ - struct lguest_device_desc *desc; +struct virtio_pci_mmio { + struct virtio_pci_common_cfg cfg; + u16 notify; + u8 isr; + u8 padding; + /* Device-specific configuration follows this. */ +}; - /* We can't trust desc values once Guest has booted: we use these. */ - unsigned int feature_len; - unsigned int num_vq; +/* This is the layout (little-endian) of the PCI config space. */ +struct pci_config { + u16 vendor_id, device_id; + u16 command, status; + u8 revid, prog_if, subclass, class; + u8 cacheline_size, lat_timer, header_type, bist; + u32 bar[6]; + u32 cardbus_cis_ptr; + u16 subsystem_vendor_id, subsystem_device_id; + u32 expansion_rom_addr; + u8 capabilities, reserved1[3]; + u32 reserved2; + u8 irq_line, irq_pin, min_grant, max_latency; + + /* Now, this is the linked capability list. */ + struct virtio_pci_cap common; + struct virtio_pci_notify_cap notify; + struct virtio_pci_cap isr; + struct virtio_pci_cap device; + struct virtio_pci_cfg_cap cfg_access; +}; +/* The device structure describes a single device. */ +struct device { /* The name of this device, for --verbose. */ const char *name; @@ -139,6 +171,25 @@ struct device { /* Is it operational */ bool running; + /* Has it written FEATURES_OK but not re-checked it? */ + bool wrote_features_ok; + + /* PCI configuration */ + union { + struct pci_config config; + u32 config_words[sizeof(struct pci_config) / sizeof(u32)]; + }; + + /* Features we offer, and those accepted. */ + u64 features, features_accepted; + + /* Device-specific config hangs off the end of this. */ + struct virtio_pci_mmio *mmio; + + /* PCI MMIO resources (all in BAR0) */ + size_t mmio_size; + u32 mmio_addr; + /* Device-specific data. */ void *priv; }; @@ -150,12 +201,15 @@ struct virtqueue { /* Which device owns me. */ struct device *dev; - /* The configuration for this queue. */ - struct lguest_vqconfig config; + /* Name for printing errors. */ + const char *name; /* The actual ring of buffers. */ struct vring vring; + /* The information about this virtqueue (we only use queue_size on) */ + struct virtio_pci_common_cfg pci_config; + /* Last available index we saw. */ u16 last_avail_idx; @@ -199,6 +253,16 @@ static struct termios orig_term; #define le32_to_cpu(v32) (v32) #define le64_to_cpu(v64) (v64) +/* + * A real device would ignore weird/non-compliant driver behaviour. We + * stop and flag it, to help debugging Linux problems. + */ +#define bad_driver(d, fmt, ...) \ + errx(1, "%s: bad driver: " fmt, (d)->name, ## __VA_ARGS__) +#define bad_driver_vq(vq, fmt, ...) \ + errx(1, "%s vq %s: bad driver: " fmt, (vq)->dev->name, \ + vq->name, ## __VA_ARGS__) + /* Is this iovec empty? */ static bool iov_empty(const struct iovec iov[], unsigned int num_iov) { @@ -211,7 +275,8 @@ static bool iov_empty(const struct iovec iov[], unsigned int num_iov) } /* Take len bytes from the front of this iovec. */ -static void iov_consume(struct iovec iov[], unsigned num_iov, +static void iov_consume(struct device *d, + struct iovec iov[], unsigned num_iov, void *dest, unsigned len) { unsigned int i; @@ -229,14 +294,7 @@ static void iov_consume(struct iovec iov[], unsigned num_iov, len -= used; } if (len != 0) - errx(1, "iovec too short!"); -} - -/* The device virtqueue descriptors are followed by feature bitmasks. */ -static u8 *get_feature_bits(struct device *dev) -{ - return (u8 *)(dev->desc + 1) - + dev->num_vq * sizeof(struct lguest_vqconfig); + bad_driver(d, "iovec too short!"); } /*L:100 @@ -309,14 +367,20 @@ static void *map_zeroed_pages(unsigned int num) return addr + getpagesize(); } -/* Get some more pages for a device. */ -static void *get_pages(unsigned int num) +/* Get some bytes which won't be mapped into the guest. */ +static unsigned long get_mmio_region(size_t size) { - void *addr = from_guest_phys(guest_limit); + unsigned long addr = guest_mmio; + size_t i; + + if (!size) + return addr; + + /* Size has to be a power of 2 (and multiple of 16) */ + for (i = 1; i < size; i <<= 1); + + guest_mmio += i; - guest_limit += num * getpagesize(); - if (guest_limit > guest_max) - errx(1, "Not enough memory for devices"); return addr; } @@ -547,9 +611,11 @@ static void tell_kernel(unsigned long start) { unsigned long args[] = { LHREQ_INITIALIZE, (unsigned long)guest_base, - guest_limit / getpagesize(), start }; - verbose("Guest: %p - %p (%#lx)\n", - guest_base, guest_base + guest_limit, guest_limit); + guest_limit / getpagesize(), start, + (guest_mmio+getpagesize()-1) / getpagesize() }; + verbose("Guest: %p - %p (%#lx, MMIO %#lx)\n", + guest_base, guest_base + guest_limit, + guest_limit, guest_mmio); lguest_fd = open_or_die("/dev/lguest", O_RDWR); if (write(lguest_fd, args, sizeof(args)) < 0) err(1, "Writing to /dev/lguest"); @@ -564,7 +630,8 @@ static void tell_kernel(unsigned long start) * we have a convenient routine which checks it and exits with an error message * if something funny is going on: */ -static void *_check_pointer(unsigned long addr, unsigned int size, +static void *_check_pointer(struct device *d, + unsigned long addr, unsigned int size, unsigned int line) { /* @@ -572,7 +639,8 @@ static void *_check_pointer(unsigned long addr, unsigned int size, * or addr + size wraps around. */ if ((addr + size) > guest_limit || (addr + size) < addr) - errx(1, "%s:%i: Invalid address %#lx", __FILE__, line, addr); + bad_driver(d, "%s:%i: Invalid address %#lx", + __FILE__, line, addr); /* * We return a pointer for the caller's convenience, now we know it's * safe to use. @@ -580,14 +648,14 @@ static void *_check_pointer(unsigned long addr, unsigned int size, return from_guest_phys(addr); } /* A macro which transparently hands the line number to the real function. */ -#define check_pointer(addr,size) _check_pointer(addr, size, __LINE__) +#define check_pointer(d,addr,size) _check_pointer(d, addr, size, __LINE__) /* * Each buffer in the virtqueues is actually a chain of descriptors. This * function returns the next descriptor in the chain, or vq->vring.num if we're * at the end. */ -static unsigned next_desc(struct vring_desc *desc, +static unsigned next_desc(struct device *d, struct vring_desc *desc, unsigned int i, unsigned int max) { unsigned int next; @@ -602,7 +670,7 @@ static unsigned next_desc(struct vring_desc *desc, wmb(); if (next >= max) - errx(1, "Desc next is %u", next); + bad_driver(d, "Desc next is %u", next); return next; } @@ -613,21 +681,48 @@ static unsigned next_desc(struct vring_desc *desc, */ static void trigger_irq(struct virtqueue *vq) { - unsigned long buf[] = { LHREQ_IRQ, vq->config.irq }; + unsigned long buf[] = { LHREQ_IRQ, vq->dev->config.irq_line }; /* Don't inform them if nothing used. */ if (!vq->pending_used) return; vq->pending_used = 0; - /* If they don't want an interrupt, don't send one... */ + /* + * 2.4.7.1: + * + * If the VIRTIO_F_EVENT_IDX feature bit is not negotiated: + * The driver MUST set flags to 0 or 1. + */ + if (vq->vring.avail->flags > 1) + bad_driver_vq(vq, "avail->flags = %u\n", vq->vring.avail->flags); + + /* + * 2.4.7.2: + * + * If the VIRTIO_F_EVENT_IDX feature bit is not negotiated: + * + * - The device MUST ignore the used_event value. + * - After the device writes a descriptor index into the used ring: + * - If flags is 1, the device SHOULD NOT send an interrupt. + * - If flags is 0, the device MUST send an interrupt. + */ if (vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) { return; } + /* + * 4.1.4.5.1: + * + * If MSI-X capability is disabled, the device MUST set the Queue + * Interrupt bit in ISR status before sending a virtqueue notification + * to the driver. + */ + vq->dev->mmio->isr = 0x1; + /* Send the Guest an interrupt tell them we used something up. */ if (write(lguest_fd, buf, sizeof(buf)) != 0) - err(1, "Triggering irq %i", vq->config.irq); + err(1, "Triggering irq %i", vq->dev->config.irq_line); } /* @@ -646,6 +741,14 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, struct vring_desc *desc; u16 last_avail = lg_last_avail(vq); + /* + * 2.4.7.1: + * + * The driver MUST handle spurious interrupts from the device. + * + * That's why this is a while loop. + */ + /* There's nothing available? */ while (last_avail == vq->vring.avail->idx) { u64 event; @@ -679,8 +782,8 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, /* Check it isn't doing very strange things with descriptor numbers. */ if ((u16)(vq->vring.avail->idx - last_avail) > vq->vring.num) - errx(1, "Guest moved used index from %u to %u", - last_avail, vq->vring.avail->idx); + bad_driver_vq(vq, "Guest moved used index from %u to %u", + last_avail, vq->vring.avail->idx); /* * Make sure we read the descriptor number *after* we read the ring @@ -697,7 +800,7 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, /* If their number is silly, that's a fatal mistake. */ if (head >= vq->vring.num) - errx(1, "Guest says index %u is available", head); + bad_driver_vq(vq, "Guest says index %u is available", head); /* When we start there are none of either input nor output. */ *out_num = *in_num = 0; @@ -712,24 +815,73 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, * that: no rmb() required. */ - /* - * If this is an indirect entry, then this buffer contains a descriptor - * table which we handle as if it's any normal descriptor chain. - */ - if (desc[i].flags & VRING_DESC_F_INDIRECT) { - if (desc[i].len % sizeof(struct vring_desc)) - errx(1, "Invalid size for indirect buffer table"); + do { + /* + * If this is an indirect entry, then this buffer contains a + * descriptor table which we handle as if it's any normal + * descriptor chain. + */ + if (desc[i].flags & VRING_DESC_F_INDIRECT) { + /* 2.4.5.3.1: + * + * The driver MUST NOT set the VIRTQ_DESC_F_INDIRECT + * flag unless the VIRTIO_F_INDIRECT_DESC feature was + * negotiated. + */ + if (!(vq->dev->features_accepted & + (1<<VIRTIO_RING_F_INDIRECT_DESC))) + bad_driver_vq(vq, "vq indirect not negotiated"); - max = desc[i].len / sizeof(struct vring_desc); - desc = check_pointer(desc[i].addr, desc[i].len); - i = 0; - } + /* + * 2.4.5.3.1: + * + * The driver MUST NOT set the VIRTQ_DESC_F_INDIRECT + * flag within an indirect descriptor (ie. only one + * table per descriptor). + */ + if (desc != vq->vring.desc) + bad_driver_vq(vq, "Indirect within indirect"); + + /* + * Proposed update VIRTIO-134 spells this out: + * + * A driver MUST NOT set both VIRTQ_DESC_F_INDIRECT + * and VIRTQ_DESC_F_NEXT in flags. + */ + if (desc[i].flags & VRING_DESC_F_NEXT) + bad_driver_vq(vq, "indirect and next together"); + + if (desc[i].len % sizeof(struct vring_desc)) + bad_driver_vq(vq, + "Invalid size for indirect table"); + /* + * 2.4.5.3.2: + * + * The device MUST ignore the write-only flag + * (flags&VIRTQ_DESC_F_WRITE) in the descriptor that + * refers to an indirect table. + * + * We ignore it here: :) + */ + + max = desc[i].len / sizeof(struct vring_desc); + desc = check_pointer(vq->dev, desc[i].addr, desc[i].len); + i = 0; + + /* 2.4.5.3.1: + * + * A driver MUST NOT create a descriptor chain longer + * than the Queue Size of the device. + */ + if (max > vq->pci_config.queue_size) + bad_driver_vq(vq, + "indirect has too many entries"); + } - do { /* Grab the first descriptor, and check it's OK. */ iov[*out_num + *in_num].iov_len = desc[i].len; iov[*out_num + *in_num].iov_base - = check_pointer(desc[i].addr, desc[i].len); + = check_pointer(vq->dev, desc[i].addr, desc[i].len); /* If this is an input descriptor, increment that count. */ if (desc[i].flags & VRING_DESC_F_WRITE) (*in_num)++; @@ -739,14 +891,15 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, * to come before any input descriptors. */ if (*in_num) - errx(1, "Descriptor has out after in"); + bad_driver_vq(vq, + "Descriptor has out after in"); (*out_num)++; } /* If we've got too many, that implies a descriptor loop. */ if (*out_num + *in_num > max) - errx(1, "Looped descriptor"); - } while ((i = next_desc(desc, i, max)) != max); + bad_driver_vq(vq, "Looped descriptor"); + } while ((i = next_desc(vq->dev, desc, i, max)) != max); return head; } @@ -803,7 +956,7 @@ static void console_input(struct virtqueue *vq) /* Make sure there's a descriptor available. */ head = wait_for_vq_desc(vq, iov, &out_num, &in_num); if (out_num) - errx(1, "Output buffers in console in queue?"); + bad_driver_vq(vq, "Output buffers in console in queue?"); /* Read into it. This is where we usually wait. */ len = readv(STDIN_FILENO, iov, in_num); @@ -856,7 +1009,7 @@ static void console_output(struct virtqueue *vq) /* We usually wait in here, for the Guest to give us something. */ head = wait_for_vq_desc(vq, iov, &out, &in); if (in) - errx(1, "Input buffers in console output queue?"); + bad_driver_vq(vq, "Input buffers in console output queue?"); /* writev can return a partial write, so we loop here. */ while (!iov_empty(iov, out)) { @@ -865,7 +1018,7 @@ static void console_output(struct virtqueue *vq) warn("Write to stdout gave %i (%d)", len, errno); break; } - iov_consume(iov, out, NULL, len); + iov_consume(vq->dev, iov, out, NULL, len); } /* @@ -894,7 +1047,7 @@ static void net_output(struct virtqueue *vq) /* We usually wait in here for the Guest to give us a packet. */ head = wait_for_vq_desc(vq, iov, &out, &in); if (in) - errx(1, "Input buffers in net output queue?"); + bad_driver_vq(vq, "Input buffers in net output queue?"); /* * Send the whole thing through to /dev/net/tun. It expects the exact * same format: what a coincidence! @@ -942,7 +1095,7 @@ static void net_input(struct virtqueue *vq) */ head = wait_for_vq_desc(vq, iov, &out, &in); if (out) - errx(1, "Output buffers in net input queue?"); + bad_driver_vq(vq, "Output buffers in net input queue?"); /* * If it looks like we'll block reading from the tun device, send them @@ -986,6 +1139,12 @@ static void kill_launcher(int signal) kill(0, SIGTERM); } +static void reset_vq_pci_config(struct virtqueue *vq) +{ + vq->pci_config.queue_size = VIRTQUEUE_NUM; + vq->pci_config.queue_enable = 0; +} + static void reset_device(struct device *dev) { struct virtqueue *vq; @@ -993,53 +1152,705 @@ static void reset_device(struct device *dev) verbose("Resetting device %s\n", dev->name); /* Clear any features they've acked. */ - memset(get_feature_bits(dev) + dev->feature_len, 0, dev->feature_len); + dev->features_accepted = 0; /* We're going to be explicitly killing threads, so ignore them. */ signal(SIGCHLD, SIG_IGN); - /* Zero out the virtqueues, get rid of their threads */ + /* + * 4.1.4.3.1: + * + * The device MUST present a 0 in queue_enable on reset. + * + * This means we set it here, and reset the saved ones in every vq. + */ + dev->mmio->cfg.queue_enable = 0; + + /* Get rid of the virtqueue threads */ for (vq = dev->vq; vq; vq = vq->next) { + vq->last_avail_idx = 0; + reset_vq_pci_config(vq); if (vq->thread != (pid_t)-1) { kill(vq->thread, SIGTERM); waitpid(vq->thread, NULL, 0); vq->thread = (pid_t)-1; } - memset(vq->vring.desc, 0, - vring_size(vq->config.num, LGUEST_VRING_ALIGN)); - lg_last_avail(vq) = 0; } dev->running = false; + dev->wrote_features_ok = false; /* Now we care if threads die. */ signal(SIGCHLD, (void *)kill_launcher); } +static void cleanup_devices(void) +{ + unsigned int i; + + for (i = 1; i < MAX_PCI_DEVICES; i++) { + struct device *d = devices.pci[i]; + if (!d) + continue; + reset_device(d); + } + + /* If we saved off the original terminal settings, restore them now. */ + if (orig_term.c_lflag & (ISIG|ICANON|ECHO)) + tcsetattr(STDIN_FILENO, TCSANOW, &orig_term); +} + +/*L:217 + * We do PCI. This is mainly done to let us test the kernel virtio PCI + * code. + */ + +/* Linux expects a PCI host bridge: ours is a dummy, and first on the bus. */ +static struct device pci_host_bridge; + +static void init_pci_host_bridge(void) +{ + pci_host_bridge.name = "PCI Host Bridge"; + pci_host_bridge.config.class = 0x06; /* bridge */ + pci_host_bridge.config.subclass = 0; /* host bridge */ + devices.pci[0] = &pci_host_bridge; +} + +/* The IO ports used to read the PCI config space. */ +#define PCI_CONFIG_ADDR 0xCF8 +#define PCI_CONFIG_DATA 0xCFC + +/* + * Not really portable, but does help readability: this is what the Guest + * writes to the PCI_CONFIG_ADDR IO port. + */ +union pci_config_addr { + struct { + unsigned mbz: 2; + unsigned offset: 6; + unsigned funcnum: 3; + unsigned devnum: 5; + unsigned busnum: 8; + unsigned reserved: 7; + unsigned enabled : 1; + } bits; + u32 val; +}; + +/* + * We cache what they wrote to the address port, so we know what they're + * talking about when they access the data port. + */ +static union pci_config_addr pci_config_addr; + +static struct device *find_pci_device(unsigned int index) +{ + return devices.pci[index]; +} + +/* PCI can do 1, 2 and 4 byte reads; we handle that here. */ +static void ioread(u16 off, u32 v, u32 mask, u32 *val) +{ + assert(off < 4); + assert(mask == 0xFF || mask == 0xFFFF || mask == 0xFFFFFFFF); + *val = (v >> (off * 8)) & mask; +} + +/* PCI can do 1, 2 and 4 byte writes; we handle that here. */ +static void iowrite(u16 off, u32 v, u32 mask, u32 *dst) +{ + assert(off < 4); + assert(mask == 0xFF || mask == 0xFFFF || mask == 0xFFFFFFFF); + *dst &= ~(mask << (off * 8)); + *dst |= (v & mask) << (off * 8); +} + +/* + * Where PCI_CONFIG_DATA accesses depends on the previous write to + * PCI_CONFIG_ADDR. + */ +static struct device *dev_and_reg(u32 *reg) +{ + if (!pci_config_addr.bits.enabled) + return NULL; + + if (pci_config_addr.bits.funcnum != 0) + return NULL; + + if (pci_config_addr.bits.busnum != 0) + return NULL; + + if (pci_config_addr.bits.offset * 4 >= sizeof(struct pci_config)) + return NULL; + + *reg = pci_config_addr.bits.offset; + return find_pci_device(pci_config_addr.bits.devnum); +} + +/* + * We can get invalid combinations of values while they're writing, so we + * only fault if they try to write with some invalid bar/offset/length. + */ +static bool valid_bar_access(struct device *d, + struct virtio_pci_cfg_cap *cfg_access) +{ + /* We only have 1 bar (BAR0) */ + if (cfg_access->cap.bar != 0) + return false; + + /* Check it's within BAR0. */ + if (cfg_access->cap.offset >= d->mmio_size + || cfg_access->cap.offset + cfg_access->cap.length > d->mmio_size) + return false; + + /* Check length is 1, 2 or 4. */ + if (cfg_access->cap.length != 1 + && cfg_access->cap.length != 2 + && cfg_access->cap.length != 4) + return false; + + /* + * 4.1.4.7.2: + * + * The driver MUST NOT write a cap.offset which is not a multiple of + * cap.length (ie. all accesses MUST be aligned). + */ + if (cfg_access->cap.offset % cfg_access->cap.length != 0) + return false; + + /* Return pointer into word in BAR0. */ + return true; +} + +/* Is this accessing the PCI config address port?. */ +static bool is_pci_addr_port(u16 port) +{ + return port >= PCI_CONFIG_ADDR && port < PCI_CONFIG_ADDR + 4; +} + +static bool pci_addr_iowrite(u16 port, u32 mask, u32 val) +{ + iowrite(port - PCI_CONFIG_ADDR, val, mask, + &pci_config_addr.val); + verbose("PCI%s: %#x/%x: bus %u dev %u func %u reg %u\n", + pci_config_addr.bits.enabled ? "" : " DISABLED", + val, mask, + pci_config_addr.bits.busnum, + pci_config_addr.bits.devnum, + pci_config_addr.bits.funcnum, + pci_config_addr.bits.offset); + return true; +} + +static void pci_addr_ioread(u16 port, u32 mask, u32 *val) +{ + ioread(port - PCI_CONFIG_ADDR, pci_config_addr.val, mask, val); +} + +/* Is this accessing the PCI config data port?. */ +static bool is_pci_data_port(u16 port) +{ + return port >= PCI_CONFIG_DATA && port < PCI_CONFIG_DATA + 4; +} + +static void emulate_mmio_write(struct device *d, u32 off, u32 val, u32 mask); + +static bool pci_data_iowrite(u16 port, u32 mask, u32 val) +{ + u32 reg, portoff; + struct device *d = dev_and_reg(®); + + /* Complain if they don't belong to a device. */ + if (!d) + return false; + + /* They can do 1 byte writes, etc. */ + portoff = port - PCI_CONFIG_DATA; + + /* + * PCI uses a weird way to determine the BAR size: the OS + * writes all 1's, and sees which ones stick. + */ + if (&d->config_words[reg] == &d->config.bar[0]) { + int i; + + iowrite(portoff, val, mask, &d->config.bar[0]); + for (i = 0; (1 << i) < d->mmio_size; i++) + d->config.bar[0] &= ~(1 << i); + return true; + } else if ((&d->config_words[reg] > &d->config.bar[0] + && &d->config_words[reg] <= &d->config.bar[6]) + || &d->config_words[reg] == &d->config.expansion_rom_addr) { + /* Allow writing to any other BAR, or expansion ROM */ + iowrite(portoff, val, mask, &d->config_words[reg]); + return true; + /* We let them overide latency timer and cacheline size */ + } else if (&d->config_words[reg] == (void *)&d->config.cacheline_size) { + /* Only let them change the first two fields. */ + if (mask == 0xFFFFFFFF) + mask = 0xFFFF; + iowrite(portoff, val, mask, &d->config_words[reg]); + return true; + } else if (&d->config_words[reg] == (void *)&d->config.command + && mask == 0xFFFF) { + /* Ignore command writes. */ + return true; + } else if (&d->config_words[reg] + == (void *)&d->config.cfg_access.cap.bar + || &d->config_words[reg] + == &d->config.cfg_access.cap.length + || &d->config_words[reg] + == &d->config.cfg_access.cap.offset) { + + /* + * The VIRTIO_PCI_CAP_PCI_CFG capability + * provides a backdoor to access the MMIO + * regions without mapping them. Weird, but + * useful. + */ + iowrite(portoff, val, mask, &d->config_words[reg]); + return true; + } else if (&d->config_words[reg] == &d->config.cfg_access.pci_cfg_data) { + u32 write_mask; + + /* + * 4.1.4.7.1: + * + * Upon detecting driver write access to pci_cfg_data, the + * device MUST execute a write access at offset cap.offset at + * BAR selected by cap.bar using the first cap.length bytes + * from pci_cfg_data. + */ + + /* Must be bar 0 */ + if (!valid_bar_access(d, &d->config.cfg_access)) + return false; + + iowrite(portoff, val, mask, &d->config.cfg_access.pci_cfg_data); + + /* + * Now emulate a write. The mask we use is set by + * len, *not* this write! + */ + write_mask = (1ULL<<(8*d->config.cfg_access.cap.length)) - 1; + verbose("Window writing %#x/%#x to bar %u, offset %u len %u\n", + d->config.cfg_access.pci_cfg_data, write_mask, + d->config.cfg_access.cap.bar, + d->config.cfg_access.cap.offset, + d->config.cfg_access.cap.length); + + emulate_mmio_write(d, d->config.cfg_access.cap.offset, + d->config.cfg_access.pci_cfg_data, + write_mask); + return true; + } + + /* + * 4.1.4.1: + * + * The driver MUST NOT write into any field of the capability + * structure, with the exception of those with cap_type + * VIRTIO_PCI_CAP_PCI_CFG... + */ + return false; +} + +static u32 emulate_mmio_read(struct device *d, u32 off, u32 mask); + +static void pci_data_ioread(u16 port, u32 mask, u32 *val) +{ + u32 reg; + struct device *d = dev_and_reg(®); + + if (!d) + return; + + /* Read through the PCI MMIO access window is special */ + if (&d->config_words[reg] == &d->config.cfg_access.pci_cfg_data) { + u32 read_mask; + + /* + * 4.1.4.7.1: + * + * Upon detecting driver read access to pci_cfg_data, the + * device MUST execute a read access of length cap.length at + * offset cap.offset at BAR selected by cap.bar and store the + * first cap.length bytes in pci_cfg_data. + */ + /* Must be bar 0 */ + if (!valid_bar_access(d, &d->config.cfg_access)) + bad_driver(d, + "Invalid cfg_access to bar%u, offset %u len %u", + d->config.cfg_access.cap.bar, + d->config.cfg_access.cap.offset, + d->config.cfg_access.cap.length); + + /* + * Read into the window. The mask we use is set by + * len, *not* this read! + */ + read_mask = (1ULL<<(8*d->config.cfg_access.cap.length))-1; + d->config.cfg_access.pci_cfg_data + = emulate_mmio_read(d, + d->config.cfg_access.cap.offset, + read_mask); + verbose("Window read %#x/%#x from bar %u, offset %u len %u\n", + d->config.cfg_access.pci_cfg_data, read_mask, + d->config.cfg_access.cap.bar, + d->config.cfg_access.cap.offset, + d->config.cfg_access.cap.length); + } + ioread(port - PCI_CONFIG_DATA, d->config_words[reg], mask, val); +} + /*L:216 - * This actually creates the thread which services the virtqueue for a device. + * This is where we emulate a handful of Guest instructions. It's ugly + * and we used to do it in the kernel but it grew over time. + */ + +/* + * We use the ptrace syscall's pt_regs struct to talk about registers + * to lguest: these macros convert the names to the offsets. + */ +#define getreg(name) getreg_off(offsetof(struct user_regs_struct, name)) +#define setreg(name, val) \ + setreg_off(offsetof(struct user_regs_struct, name), (val)) + +static u32 getreg_off(size_t offset) +{ + u32 r; + unsigned long args[] = { LHREQ_GETREG, offset }; + + if (pwrite(lguest_fd, args, sizeof(args), cpu_id) < 0) + err(1, "Getting register %u", offset); + if (pread(lguest_fd, &r, sizeof(r), cpu_id) != sizeof(r)) + err(1, "Reading register %u", offset); + + return r; +} + +static void setreg_off(size_t offset, u32 val) +{ + unsigned long args[] = { LHREQ_SETREG, offset, val }; + + if (pwrite(lguest_fd, args, sizeof(args), cpu_id) < 0) + err(1, "Setting register %u", offset); +} + +/* Get register by instruction encoding */ +static u32 getreg_num(unsigned regnum, u32 mask) +{ + /* 8 bit ops use regnums 4-7 for high parts of word */ + if (mask == 0xFF && (regnum & 0x4)) + return getreg_num(regnum & 0x3, 0xFFFF) >> 8; + + switch (regnum) { + case 0: return getreg(eax) & mask; + case 1: return getreg(ecx) & mask; + case 2: return getreg(edx) & mask; + case 3: return getreg(ebx) & mask; + case 4: return getreg(esp) & mask; + case 5: return getreg(ebp) & mask; + case 6: return getreg(esi) & mask; + case 7: return getreg(edi) & mask; + } + abort(); +} + +/* Set register by instruction encoding */ +static void setreg_num(unsigned regnum, u32 val, u32 mask) +{ + /* Don't try to set bits out of range */ + assert(~(val & ~mask)); + + /* 8 bit ops use regnums 4-7 for high parts of word */ + if (mask == 0xFF && (regnum & 0x4)) { + /* Construct the 16 bits we want. */ + val = (val << 8) | getreg_num(regnum & 0x3, 0xFF); + setreg_num(regnum & 0x3, val, 0xFFFF); + return; + } + + switch (regnum) { + case 0: setreg(eax, val | (getreg(eax) & ~mask)); return; + case 1: setreg(ecx, val | (getreg(ecx) & ~mask)); return; + case 2: setreg(edx, val | (getreg(edx) & ~mask)); return; + case 3: setreg(ebx, val | (getreg(ebx) & ~mask)); return; + case 4: setreg(esp, val | (getreg(esp) & ~mask)); return; + case 5: setreg(ebp, val | (getreg(ebp) & ~mask)); return; + case 6: setreg(esi, val | (getreg(esi) & ~mask)); return; + case 7: setreg(edi, val | (getreg(edi) & ~mask)); return; + } + abort(); +} + +/* Get bytes of displacement appended to instruction, from r/m encoding */ +static u32 insn_displacement_len(u8 mod_reg_rm) +{ + /* Switch on the mod bits */ + switch (mod_reg_rm >> 6) { + case 0: + /* If mod == 0, and r/m == 101, 16-bit displacement follows */ + if ((mod_reg_rm & 0x7) == 0x5) + return 2; + /* Normally, mod == 0 means no literal displacement */ + return 0; + case 1: + /* One byte displacement */ + return 1; + case 2: + /* Four byte displacement */ + return 4; + case 3: + /* Register mode */ + return 0; + } + abort(); +} + +static void emulate_insn(const u8 insn[]) +{ + unsigned long args[] = { LHREQ_TRAP, 13 }; + unsigned int insnlen = 0, in = 0, small_operand = 0, byte_access; + unsigned int eax, port, mask; + /* + * Default is to return all-ones on IO port reads, which traditionally + * means "there's nothing there". + */ + u32 val = 0xFFFFFFFF; + + /* + * This must be the Guest kernel trying to do something, not userspace! + * The bottom two bits of the CS segment register are the privilege + * level. + */ + if ((getreg(xcs) & 3) != 0x1) + goto no_emulate; + + /* Decoding x86 instructions is icky. */ + + /* + * Around 2.6.33, the kernel started using an emulation for the + * cmpxchg8b instruction in early boot on many configurations. This + * code isn't paravirtualized, and it tries to disable interrupts. + * Ignore it, which will Mostly Work. + */ + if (insn[insnlen] == 0xfa) { + /* "cli", or Clear Interrupt Enable instruction. Skip it. */ + insnlen = 1; + goto skip_insn; + } + + /* + * 0x66 is an "operand prefix". It means a 16, not 32 bit in/out. + */ + if (insn[insnlen] == 0x66) { + small_operand = 1; + /* The instruction is 1 byte so far, read the next byte. */ + insnlen = 1; + } + + /* If the lower bit isn't set, it's a single byte access */ + byte_access = !(insn[insnlen] & 1); + + /* + * Now we can ignore the lower bit and decode the 4 opcodes + * we need to emulate. + */ + switch (insn[insnlen] & 0xFE) { + case 0xE4: /* in <next byte>,%al */ + port = insn[insnlen+1]; + insnlen += 2; + in = 1; + break; + case 0xEC: /* in (%dx),%al */ + port = getreg(edx) & 0xFFFF; + insnlen += 1; + in = 1; + break; + case 0xE6: /* out %al,<next byte> */ + port = insn[insnlen+1]; + insnlen += 2; + break; + case 0xEE: /* out %al,(%dx) */ + port = getreg(edx) & 0xFFFF; + insnlen += 1; + break; + default: + /* OK, we don't know what this is, can't emulate. */ + goto no_emulate; + } + + /* Set a mask of the 1, 2 or 4 bytes, depending on size of IO */ + if (byte_access) + mask = 0xFF; + else if (small_operand) + mask = 0xFFFF; + else + mask = 0xFFFFFFFF; + + /* + * If it was an "IN" instruction, they expect the result to be read + * into %eax, so we change %eax. + */ + eax = getreg(eax); + + if (in) { + /* This is the PS/2 keyboard status; 1 means ready for output */ + if (port == 0x64) + val = 1; + else if (is_pci_addr_port(port)) + pci_addr_ioread(port, mask, &val); + else if (is_pci_data_port(port)) + pci_data_ioread(port, mask, &val); + + /* Clear the bits we're about to read */ + eax &= ~mask; + /* Copy bits in from val. */ + eax |= val & mask; + /* Now update the register. */ + setreg(eax, eax); + } else { + if (is_pci_addr_port(port)) { + if (!pci_addr_iowrite(port, mask, eax)) + goto bad_io; + } else if (is_pci_data_port(port)) { + if (!pci_data_iowrite(port, mask, eax)) + goto bad_io; + } + /* There are many other ports, eg. CMOS clock, serial + * and parallel ports, so we ignore them all. */ + } + + verbose("IO %s of %x to %u: %#08x\n", + in ? "IN" : "OUT", mask, port, eax); +skip_insn: + /* Finally, we've "done" the instruction, so move past it. */ + setreg(eip, getreg(eip) + insnlen); + return; + +bad_io: + warnx("Attempt to %s port %u (%#x mask)", + in ? "read from" : "write to", port, mask); + +no_emulate: + /* Inject trap into Guest. */ + if (write(lguest_fd, args, sizeof(args)) < 0) + err(1, "Reinjecting trap 13 for fault at %#x", getreg(eip)); +} + +static struct device *find_mmio_region(unsigned long paddr, u32 *off) +{ + unsigned int i; + + for (i = 1; i < MAX_PCI_DEVICES; i++) { + struct device *d = devices.pci[i]; + + if (!d) + continue; + if (paddr < d->mmio_addr) + continue; + if (paddr >= d->mmio_addr + d->mmio_size) + continue; + *off = paddr - d->mmio_addr; + return d; + } + return NULL; +} + +/* FIXME: Use vq array. */ +static struct virtqueue *vq_by_num(struct device *d, u32 num) +{ + struct virtqueue *vq = d->vq; + + while (num-- && vq) + vq = vq->next; + + return vq; +} + +static void save_vq_config(const struct virtio_pci_common_cfg *cfg, + struct virtqueue *vq) +{ + vq->pci_config = *cfg; +} + +static void restore_vq_config(struct virtio_pci_common_cfg *cfg, + struct virtqueue *vq) +{ + /* Only restore the per-vq part */ + size_t off = offsetof(struct virtio_pci_common_cfg, queue_size); + + memcpy((void *)cfg + off, (void *)&vq->pci_config + off, + sizeof(*cfg) - off); +} + +/* + * 4.1.4.3.2: + * + * The driver MUST configure the other virtqueue fields before + * enabling the virtqueue with queue_enable. + * + * When they enable the virtqueue, we check that their setup is valid. */ -static void create_thread(struct virtqueue *vq) +static void check_virtqueue(struct device *d, struct virtqueue *vq) +{ + /* Because lguest is 32 bit, all the descriptor high bits must be 0 */ + if (vq->pci_config.queue_desc_hi + || vq->pci_config.queue_avail_hi + || vq->pci_config.queue_used_hi) + bad_driver_vq(vq, "invalid 64-bit queue address"); + + /* + * 2.4.1: + * + * The driver MUST ensure that the physical address of the first byte + * of each virtqueue part is a multiple of the specified alignment + * value in the above table. + */ + if (vq->pci_config.queue_desc_lo % 16 + || vq->pci_config.queue_avail_lo % 2 + || vq->pci_config.queue_used_lo % 4) + bad_driver_vq(vq, "invalid alignment in queue addresses"); + + /* Initialize the virtqueue and check they're all in range. */ + vq->vring.num = vq->pci_config.queue_size; + vq->vring.desc = check_pointer(vq->dev, + vq->pci_config.queue_desc_lo, + sizeof(*vq->vring.desc) * vq->vring.num); + vq->vring.avail = check_pointer(vq->dev, + vq->pci_config.queue_avail_lo, + sizeof(*vq->vring.avail) + + (sizeof(vq->vring.avail->ring[0]) + * vq->vring.num)); + vq->vring.used = check_pointer(vq->dev, + vq->pci_config.queue_used_lo, + sizeof(*vq->vring.used) + + (sizeof(vq->vring.used->ring[0]) + * vq->vring.num)); + + /* + * 2.4.9.1: + * + * The driver MUST initialize flags in the used ring to 0 + * when allocating the used ring. + */ + if (vq->vring.used->flags != 0) + bad_driver_vq(vq, "invalid initial used.flags %#x", + vq->vring.used->flags); +} + +static void start_virtqueue(struct virtqueue *vq) { /* * Create stack for thread. Since the stack grows upwards, we point * the stack pointer to the end of this region. */ char *stack = malloc(32768); - unsigned long args[] = { LHREQ_EVENTFD, - vq->config.pfn*getpagesize(), 0 }; /* Create a zero-initialized eventfd. */ vq->eventfd = eventfd(0, 0); if (vq->eventfd < 0) err(1, "Creating eventfd"); - args[2] = vq->eventfd; - - /* - * Attach an eventfd to this virtqueue: it will go off when the Guest - * does an LHCALL_NOTIFY for this vq. - */ - if (write(lguest_fd, &args, sizeof(args)) != 0) - err(1, "Attaching eventfd"); /* * CLONE_VM: because it has to access the Guest memory, and SIGCHLD so @@ -1048,167 +1859,531 @@ static void create_thread(struct virtqueue *vq) vq->thread = clone(do_thread, stack + 32768, CLONE_VM | SIGCHLD, vq); if (vq->thread == (pid_t)-1) err(1, "Creating clone"); - - /* We close our local copy now the child has it. */ - close(vq->eventfd); } -static void start_device(struct device *dev) +static void start_virtqueues(struct device *d) { - unsigned int i; struct virtqueue *vq; - verbose("Device %s OK: offered", dev->name); - for (i = 0; i < dev->feature_len; i++) - verbose(" %02x", get_feature_bits(dev)[i]); - verbose(", accepted"); - for (i = 0; i < dev->feature_len; i++) - verbose(" %02x", get_feature_bits(dev) - [dev->feature_len+i]); - - for (vq = dev->vq; vq; vq = vq->next) { - if (vq->service) - create_thread(vq); + for (vq = d->vq; vq; vq = vq->next) { + if (vq->pci_config.queue_enable) + start_virtqueue(vq); } - dev->running = true; } -static void cleanup_devices(void) +static void emulate_mmio_write(struct device *d, u32 off, u32 val, u32 mask) { - struct device *dev; + struct virtqueue *vq; - for (dev = devices.dev; dev; dev = dev->next) - reset_device(dev); + switch (off) { + case offsetof(struct virtio_pci_mmio, cfg.device_feature_select): + /* + * 4.1.4.3.1: + * + * The device MUST present the feature bits it is offering in + * device_feature, starting at bit device_feature_select ∗ 32 + * for any device_feature_select written by the driver + */ + if (val == 0) + d->mmio->cfg.device_feature = d->features; + else if (val == 1) + d->mmio->cfg.device_feature = (d->features >> 32); + else + d->mmio->cfg.device_feature = 0; + goto feature_write_through32; + case offsetof(struct virtio_pci_mmio, cfg.guest_feature_select): + if (val > 1) + bad_driver(d, "Unexpected driver select %u", val); + goto feature_write_through32; + case offsetof(struct virtio_pci_mmio, cfg.guest_feature): + if (d->mmio->cfg.guest_feature_select == 0) { + d->features_accepted &= ~((u64)0xFFFFFFFF); + d->features_accepted |= val; + } else { + assert(d->mmio->cfg.guest_feature_select == 1); + d->features_accepted &= 0xFFFFFFFF; + d->features_accepted |= ((u64)val) << 32; + } + /* + * 2.2.1: + * + * The driver MUST NOT accept a feature which the device did + * not offer + */ + if (d->features_accepted & ~d->features) + bad_driver(d, "over-accepted features %#llx of %#llx", + d->features_accepted, d->features); + goto feature_write_through32; + case offsetof(struct virtio_pci_mmio, cfg.device_status): { + u8 prev; + + verbose("%s: device status -> %#x\n", d->name, val); + /* + * 4.1.4.3.1: + * + * The device MUST reset when 0 is written to device_status, + * and present a 0 in device_status once that is done. + */ + if (val == 0) { + reset_device(d); + goto write_through8; + } - /* If we saved off the original terminal settings, restore them now. */ - if (orig_term.c_lflag & (ISIG|ICANON|ECHO)) - tcsetattr(STDIN_FILENO, TCSANOW, &orig_term); -} + /* 2.1.1: The driver MUST NOT clear a device status bit. */ + if (d->mmio->cfg.device_status & ~val) + bad_driver(d, "unset of device status bit %#x -> %#x", + d->mmio->cfg.device_status, val); -/* When the Guest tells us they updated the status field, we handle it. */ -static void update_device_status(struct device *dev) -{ - /* A zero status is a reset, otherwise it's a set of flags. */ - if (dev->desc->status == 0) - reset_device(dev); - else if (dev->desc->status & VIRTIO_CONFIG_S_FAILED) { - warnx("Device %s configuration FAILED", dev->name); - if (dev->running) - reset_device(dev); - } else { - if (dev->running) - err(1, "Device %s features finalized twice", dev->name); - start_device(dev); + /* + * 2.1.2: + * + * The device MUST NOT consume buffers or notify the driver + * before DRIVER_OK. + */ + if (val & VIRTIO_CONFIG_S_DRIVER_OK + && !(d->mmio->cfg.device_status & VIRTIO_CONFIG_S_DRIVER_OK)) + start_virtqueues(d); + + /* + * 3.1.1: + * + * The driver MUST follow this sequence to initialize a device: + * - Reset the device. + * - Set the ACKNOWLEDGE status bit: the guest OS has + * notice the device. + * - Set the DRIVER status bit: the guest OS knows how + * to drive the device. + * - Read device feature bits, and write the subset + * of feature bits understood by the OS and driver + * to the device. During this step the driver MAY + * read (but MUST NOT write) the device-specific + * configuration fields to check that it can + * support the device before accepting it. + * - Set the FEATURES_OK status bit. The driver + * MUST not accept new feature bits after this + * step. + * - Re-read device status to ensure the FEATURES_OK + * bit is still set: otherwise, the device does + * not support our subset of features and the + * device is unusable. + * - Perform device-specific setup, including + * discovery of virtqueues for the device, + * optional per-bus setup, reading and possibly + * writing the device’s virtio configuration + * space, and population of virtqueues. + * - Set the DRIVER_OK status bit. At this point the + * device is “live”. + */ + prev = 0; + switch (val & ~d->mmio->cfg.device_status) { + case VIRTIO_CONFIG_S_DRIVER_OK: + prev |= VIRTIO_CONFIG_S_FEATURES_OK; /* fall thru */ + case VIRTIO_CONFIG_S_FEATURES_OK: + prev |= VIRTIO_CONFIG_S_DRIVER; /* fall thru */ + case VIRTIO_CONFIG_S_DRIVER: + prev |= VIRTIO_CONFIG_S_ACKNOWLEDGE; /* fall thru */ + case VIRTIO_CONFIG_S_ACKNOWLEDGE: + break; + default: + bad_driver(d, "unknown device status bit %#x -> %#x", + d->mmio->cfg.device_status, val); + } + if (d->mmio->cfg.device_status != prev) + bad_driver(d, "unexpected status transition %#x -> %#x", + d->mmio->cfg.device_status, val); + + /* If they just wrote FEATURES_OK, we make sure they read */ + switch (val & ~d->mmio->cfg.device_status) { + case VIRTIO_CONFIG_S_FEATURES_OK: + d->wrote_features_ok = true; + break; + case VIRTIO_CONFIG_S_DRIVER_OK: + if (d->wrote_features_ok) + bad_driver(d, "did not re-read FEATURES_OK"); + break; + } + goto write_through8; } -} + case offsetof(struct virtio_pci_mmio, cfg.queue_select): + vq = vq_by_num(d, val); + /* + * 4.1.4.3.1: + * + * The device MUST present a 0 in queue_size if the virtqueue + * corresponding to the current queue_select is unavailable. + */ + if (!vq) { + d->mmio->cfg.queue_size = 0; + goto write_through16; + } + /* Save registers for old vq, if it was a valid vq */ + if (d->mmio->cfg.queue_size) + save_vq_config(&d->mmio->cfg, + vq_by_num(d, d->mmio->cfg.queue_select)); + /* Restore the registers for the queue they asked for */ + restore_vq_config(&d->mmio->cfg, vq); + goto write_through16; + case offsetof(struct virtio_pci_mmio, cfg.queue_size): + /* + * 4.1.4.3.2: + * + * The driver MUST NOT write a value which is not a power of 2 + * to queue_size. + */ + if (val & (val-1)) + bad_driver(d, "invalid queue size %u", val); + if (d->mmio->cfg.queue_enable) + bad_driver(d, "changing queue size on live device"); + goto write_through16; + case offsetof(struct virtio_pci_mmio, cfg.queue_msix_vector): + bad_driver(d, "attempt to set MSIX vector to %u", val); + case offsetof(struct virtio_pci_mmio, cfg.queue_enable): { + struct virtqueue *vq = vq_by_num(d, d->mmio->cfg.queue_select); -/*L:215 - * This is the generic routine we call when the Guest uses LHCALL_NOTIFY. In - * particular, it's used to notify us of device status changes during boot. - */ -static void handle_output(unsigned long addr) -{ - struct device *i; + /* + * 4.1.4.3.2: + * + * The driver MUST NOT write a 0 to queue_enable. + */ + if (val != 1) + bad_driver(d, "setting queue_enable to %u", val); - /* Check each device. */ - for (i = devices.dev; i; i = i->next) { - struct virtqueue *vq; + /* + * 3.1.1: + * + * 7. Perform device-specific setup, including discovery of + * virtqueues for the device, optional per-bus setup, + * reading and possibly writing the device’s virtio + * configuration space, and population of virtqueues. + * 8. Set the DRIVER_OK status bit. + * + * All our devices require all virtqueues to be enabled, so + * they should have done that before setting DRIVER_OK. + */ + if (d->mmio->cfg.device_status & VIRTIO_CONFIG_S_DRIVER_OK) + bad_driver(d, "enabling vq after DRIVER_OK"); + d->mmio->cfg.queue_enable = val; + save_vq_config(&d->mmio->cfg, vq); + check_virtqueue(d, vq); + goto write_through16; + } + case offsetof(struct virtio_pci_mmio, cfg.queue_notify_off): + bad_driver(d, "attempt to write to queue_notify_off"); + case offsetof(struct virtio_pci_mmio, cfg.queue_desc_lo): + case offsetof(struct virtio_pci_mmio, cfg.queue_desc_hi): + case offsetof(struct virtio_pci_mmio, cfg.queue_avail_lo): + case offsetof(struct virtio_pci_mmio, cfg.queue_avail_hi): + case offsetof(struct virtio_pci_mmio, cfg.queue_used_lo): + case offsetof(struct virtio_pci_mmio, cfg.queue_used_hi): /* - * Notifications to device descriptors mean they updated the - * device status. + * 4.1.4.3.2: + * + * The driver MUST configure the other virtqueue fields before + * enabling the virtqueue with queue_enable. */ - if (from_guest_phys(addr) == i->desc) { - update_device_status(i); - return; - } + if (d->mmio->cfg.queue_enable) + bad_driver(d, "changing queue on live device"); + + /* + * 3.1.1: + * + * The driver MUST follow this sequence to initialize a device: + *... + * 5. Set the FEATURES_OK status bit. The driver MUST not + * accept new feature bits after this step. + */ + if (!(d->mmio->cfg.device_status & VIRTIO_CONFIG_S_FEATURES_OK)) + bad_driver(d, "setting up vq before FEATURES_OK"); - /* Devices should not be used before features are finalized. */ - for (vq = i->vq; vq; vq = vq->next) { - if (addr != vq->config.pfn*getpagesize()) - continue; - errx(1, "Notification on %s before setup!", i->name); + /* + * 6. Re-read device status to ensure the FEATURES_OK bit is + * still set... + */ + if (d->wrote_features_ok) + bad_driver(d, "didn't re-read FEATURES_OK before setup"); + + goto write_through32; + case offsetof(struct virtio_pci_mmio, notify): + vq = vq_by_num(d, val); + if (!vq) + bad_driver(d, "Invalid vq notification on %u", val); + /* Notify the process handling this vq by adding 1 to eventfd */ + write(vq->eventfd, "\1\0\0\0\0\0\0\0", 8); + goto write_through16; + case offsetof(struct virtio_pci_mmio, isr): + bad_driver(d, "Unexpected write to isr"); + /* Weird corner case: write to emerg_wr of console */ + case sizeof(struct virtio_pci_mmio) + + offsetof(struct virtio_console_config, emerg_wr): + if (strcmp(d->name, "console") == 0) { + char c = val; + write(STDOUT_FILENO, &c, 1); + goto write_through32; } + /* Fall through... */ + default: + /* + * 4.1.4.3.2: + * + * The driver MUST NOT write to device_feature, num_queues, + * config_generation or queue_notify_off. + */ + bad_driver(d, "Unexpected write to offset %u", off); } +feature_write_through32: /* - * Early console write is done using notify on a nul-terminated string - * in Guest memory. It's also great for hacking debugging messages - * into a Guest. + * 3.1.1: + * + * The driver MUST follow this sequence to initialize a device: + *... + * - Set the DRIVER status bit: the guest OS knows how + * to drive the device. + * - Read device feature bits, and write the subset + * of feature bits understood by the OS and driver + * to the device. + *... + * - Set the FEATURES_OK status bit. The driver MUST not + * accept new feature bits after this step. */ - if (addr >= guest_limit) - errx(1, "Bad NOTIFY %#lx", addr); + if (!(d->mmio->cfg.device_status & VIRTIO_CONFIG_S_DRIVER)) + bad_driver(d, "feature write before VIRTIO_CONFIG_S_DRIVER"); + if (d->mmio->cfg.device_status & VIRTIO_CONFIG_S_FEATURES_OK) + bad_driver(d, "feature write after VIRTIO_CONFIG_S_FEATURES_OK"); - write(STDOUT_FILENO, from_guest_phys(addr), - strnlen(from_guest_phys(addr), guest_limit - addr)); + /* + * 4.1.3.1: + * + * The driver MUST access each field using the “natural” access + * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for + * 16-bit fields and 8-bit accesses for 8-bit fields. + */ +write_through32: + if (mask != 0xFFFFFFFF) { + bad_driver(d, "non-32-bit write to offset %u (%#x)", + off, getreg(eip)); + return; + } + memcpy((char *)d->mmio + off, &val, 4); + return; + +write_through16: + if (mask != 0xFFFF) + bad_driver(d, "non-16-bit write to offset %u (%#x)", + off, getreg(eip)); + memcpy((char *)d->mmio + off, &val, 2); + return; + +write_through8: + if (mask != 0xFF) + bad_driver(d, "non-8-bit write to offset %u (%#x)", + off, getreg(eip)); + memcpy((char *)d->mmio + off, &val, 1); + return; } -/*L:190 - * Device Setup - * - * All devices need a descriptor so the Guest knows it exists, and a "struct - * device" so the Launcher can keep track of it. We have common helper - * routines to allocate and manage them. - */ - -/* - * The layout of the device page is a "struct lguest_device_desc" followed by a - * number of virtqueue descriptors, then two sets of feature bits, then an - * array of configuration bytes. This routine returns the configuration - * pointer. - */ -static u8 *device_config(const struct device *dev) +static u32 emulate_mmio_read(struct device *d, u32 off, u32 mask) { - return (void *)(dev->desc + 1) - + dev->num_vq * sizeof(struct lguest_vqconfig) - + dev->feature_len * 2; + u8 isr; + u32 val = 0; + + switch (off) { + case offsetof(struct virtio_pci_mmio, cfg.device_feature_select): + case offsetof(struct virtio_pci_mmio, cfg.device_feature): + case offsetof(struct virtio_pci_mmio, cfg.guest_feature_select): + case offsetof(struct virtio_pci_mmio, cfg.guest_feature): + /* + * 3.1.1: + * + * The driver MUST follow this sequence to initialize a device: + *... + * - Set the DRIVER status bit: the guest OS knows how + * to drive the device. + * - Read device feature bits, and write the subset + * of feature bits understood by the OS and driver + * to the device. + */ + if (!(d->mmio->cfg.device_status & VIRTIO_CONFIG_S_DRIVER)) + bad_driver(d, + "feature read before VIRTIO_CONFIG_S_DRIVER"); + goto read_through32; + case offsetof(struct virtio_pci_mmio, cfg.msix_config): + bad_driver(d, "read of msix_config"); + case offsetof(struct virtio_pci_mmio, cfg.num_queues): + goto read_through16; + case offsetof(struct virtio_pci_mmio, cfg.device_status): + /* As they did read, any write of FEATURES_OK is now fine. */ + d->wrote_features_ok = false; + goto read_through8; + case offsetof(struct virtio_pci_mmio, cfg.config_generation): + /* + * 4.1.4.3.1: + * + * The device MUST present a changed config_generation after + * the driver has read a device-specific configuration value + * which has changed since any part of the device-specific + * configuration was last read. + * + * This is simple: none of our devices change config, so this + * is always 0. + */ + goto read_through8; + case offsetof(struct virtio_pci_mmio, notify): + /* + * 3.1.1: + * + * The driver MUST NOT notify the device before setting + * DRIVER_OK. + */ + if (!(d->mmio->cfg.device_status & VIRTIO_CONFIG_S_DRIVER_OK)) + bad_driver(d, "notify before VIRTIO_CONFIG_S_DRIVER_OK"); + goto read_through16; + case offsetof(struct virtio_pci_mmio, isr): + if (mask != 0xFF) + bad_driver(d, "non-8-bit read from offset %u (%#x)", + off, getreg(eip)); + isr = d->mmio->isr; + /* + * 4.1.4.5.1: + * + * The device MUST reset ISR status to 0 on driver read. + */ + d->mmio->isr = 0; + return isr; + case offsetof(struct virtio_pci_mmio, padding): + bad_driver(d, "read from padding (%#x)", getreg(eip)); + default: + /* Read from device config space, beware unaligned overflow */ + if (off > d->mmio_size - 4) + bad_driver(d, "read past end (%#x)", getreg(eip)); + + /* + * 3.1.1: + * The driver MUST follow this sequence to initialize a device: + *... + * 3. Set the DRIVER status bit: the guest OS knows how to + * drive the device. + * 4. Read device feature bits, and write the subset of + * feature bits understood by the OS and driver to the + * device. During this step the driver MAY read (but MUST NOT + * write) the device-specific configuration fields to check + * that it can support the device before accepting it. + */ + if (!(d->mmio->cfg.device_status & VIRTIO_CONFIG_S_DRIVER)) + bad_driver(d, + "config read before VIRTIO_CONFIG_S_DRIVER"); + + if (mask == 0xFFFFFFFF) + goto read_through32; + else if (mask == 0xFFFF) + goto read_through16; + else + goto read_through8; + } + + /* + * 4.1.3.1: + * + * The driver MUST access each field using the “natural” access + * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for + * 16-bit fields and 8-bit accesses for 8-bit fields. + */ +read_through32: + if (mask != 0xFFFFFFFF) + bad_driver(d, "non-32-bit read to offset %u (%#x)", + off, getreg(eip)); + memcpy(&val, (char *)d->mmio + off, 4); + return val; + +read_through16: + if (mask != 0xFFFF) + bad_driver(d, "non-16-bit read to offset %u (%#x)", + off, getreg(eip)); + memcpy(&val, (char *)d->mmio + off, 2); + return val; + +read_through8: + if (mask != 0xFF) + bad_driver(d, "non-8-bit read to offset %u (%#x)", + off, getreg(eip)); + memcpy(&val, (char *)d->mmio + off, 1); + return val; } -/* - * This routine allocates a new "struct lguest_device_desc" from descriptor - * table page just above the Guest's normal memory. It returns a pointer to - * that descriptor. - */ -static struct lguest_device_desc *new_dev_desc(u16 type) +static void emulate_mmio(unsigned long paddr, const u8 *insn) { - struct lguest_device_desc d = { .type = type }; - void *p; + u32 val, off, mask = 0xFFFFFFFF, insnlen = 0; + struct device *d = find_mmio_region(paddr, &off); + unsigned long args[] = { LHREQ_TRAP, 14 }; - /* Figure out where the next device config is, based on the last one. */ - if (devices.lastdev) - p = device_config(devices.lastdev) - + devices.lastdev->desc->config_len; - else - p = devices.descpage; + if (!d) { + warnx("MMIO touching %#08lx (not a device)", paddr); + goto reinject; + } + + /* Prefix makes it a 16 bit op */ + if (insn[0] == 0x66) { + mask = 0xFFFF; + insnlen++; + } - /* We only have one page for all the descriptors. */ - if (p + sizeof(d) > (void *)devices.descpage + getpagesize()) - errx(1, "Too many devices"); + /* iowrite */ + if (insn[insnlen] == 0x89) { + /* Next byte is r/m byte: bits 3-5 are register. */ + val = getreg_num((insn[insnlen+1] >> 3) & 0x7, mask); + emulate_mmio_write(d, off, val, mask); + insnlen += 2 + insn_displacement_len(insn[insnlen+1]); + } else if (insn[insnlen] == 0x8b) { /* ioread */ + /* Next byte is r/m byte: bits 3-5 are register. */ + val = emulate_mmio_read(d, off, mask); + setreg_num((insn[insnlen+1] >> 3) & 0x7, val, mask); + insnlen += 2 + insn_displacement_len(insn[insnlen+1]); + } else if (insn[0] == 0x88) { /* 8-bit iowrite */ + mask = 0xff; + /* Next byte is r/m byte: bits 3-5 are register. */ + val = getreg_num((insn[1] >> 3) & 0x7, mask); + emulate_mmio_write(d, off, val, mask); + insnlen = 2 + insn_displacement_len(insn[1]); + } else if (insn[0] == 0x8a) { /* 8-bit ioread */ + mask = 0xff; + val = emulate_mmio_read(d, off, mask); + setreg_num((insn[1] >> 3) & 0x7, val, mask); + insnlen = 2 + insn_displacement_len(insn[1]); + } else { + warnx("Unknown MMIO instruction touching %#08lx:" + " %02x %02x %02x %02x at %u", + paddr, insn[0], insn[1], insn[2], insn[3], getreg(eip)); + reinject: + /* Inject trap into Guest. */ + if (write(lguest_fd, args, sizeof(args)) < 0) + err(1, "Reinjecting trap 14 for fault at %#x", + getreg(eip)); + return; + } - /* p might not be aligned, so we memcpy in. */ - return memcpy(p, &d, sizeof(d)); + /* Finally, we've "done" the instruction, so move past it. */ + setreg(eip, getreg(eip) + insnlen); } -/* - * Each device descriptor is followed by the description of its virtqueues. We - * specify how many descriptors the virtqueue is to have. +/*L:190 + * Device Setup + * + * All devices need a descriptor so the Guest knows it exists, and a "struct + * device" so the Launcher can keep track of it. We have common helper + * routines to allocate and manage them. */ -static void add_virtqueue(struct device *dev, unsigned int num_descs, - void (*service)(struct virtqueue *)) +static void add_pci_virtqueue(struct device *dev, + void (*service)(struct virtqueue *), + const char *name) { - unsigned int pages; struct virtqueue **i, *vq = malloc(sizeof(*vq)); - void *p; - - /* First we need some memory for this virtqueue. */ - pages = (vring_size(num_descs, LGUEST_VRING_ALIGN) + getpagesize() - 1) - / getpagesize(); - p = get_pages(pages); /* Initialize the virtqueue */ vq->next = NULL; vq->last_avail_idx = 0; vq->dev = dev; + vq->name = name; /* * This is the routine the service thread will run, and its Process ID @@ -1218,25 +2393,11 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, vq->thread = (pid_t)-1; /* Initialize the configuration. */ - vq->config.num = num_descs; - vq->config.irq = devices.next_irq++; - vq->config.pfn = to_guest_phys(p) / getpagesize(); - - /* Initialize the vring. */ - vring_init(&vq->vring, num_descs, p, LGUEST_VRING_ALIGN); - - /* - * Append virtqueue to this device's descriptor. We use - * device_config() to get the end of the device's current virtqueues; - * we check that we haven't added any config or feature information - * yet, otherwise we'd be overwriting them. - */ - assert(dev->desc->config_len == 0 && dev->desc->feature_len == 0); - memcpy(device_config(dev), &vq->config, sizeof(vq->config)); - dev->num_vq++; - dev->desc->num_vq++; + reset_vq_pci_config(vq); + vq->pci_config.queue_notify_off = 0; - verbose("Virtqueue page %#lx\n", to_guest_phys(p)); + /* Add one to the number of queues */ + vq->dev->mmio->cfg.num_queues++; /* * Add to tail of list, so dev->vq is first vq, dev->vq->next is @@ -1246,73 +2407,239 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, *i = vq; } -/* - * The first half of the feature bitmask is for us to advertise features. The - * second half is for the Guest to accept features. - */ -static void add_feature(struct device *dev, unsigned bit) +/* The Guest accesses the feature bits via the PCI common config MMIO region */ +static void add_pci_feature(struct device *dev, unsigned bit) { - u8 *features = get_feature_bits(dev); + dev->features |= (1ULL << bit); +} - /* We can't extend the feature bits once we've added config bytes */ - if (dev->desc->feature_len <= bit / CHAR_BIT) { - assert(dev->desc->config_len == 0); - dev->feature_len = dev->desc->feature_len = (bit/CHAR_BIT) + 1; - } +/* For devices with no config. */ +static void no_device_config(struct device *dev) +{ + dev->mmio_addr = get_mmio_region(dev->mmio_size); - features[bit / CHAR_BIT] |= (1 << (bit % CHAR_BIT)); + dev->config.bar[0] = dev->mmio_addr; + /* Bottom 4 bits must be zero */ + assert(~(dev->config.bar[0] & 0xF)); +} + +/* This puts the device config into BAR0 */ +static void set_device_config(struct device *dev, const void *conf, size_t len) +{ + /* Set up BAR 0 */ + dev->mmio_size += len; + dev->mmio = realloc(dev->mmio, dev->mmio_size); + memcpy(dev->mmio + 1, conf, len); + + /* + * 4.1.4.6: + * + * The device MUST present at least one VIRTIO_PCI_CAP_DEVICE_CFG + * capability for any device type which has a device-specific + * configuration. + */ + /* Hook up device cfg */ + dev->config.cfg_access.cap.cap_next + = offsetof(struct pci_config, device); + + /* + * 4.1.4.6.1: + * + * The offset for the device-specific configuration MUST be 4-byte + * aligned. + */ + assert(dev->config.cfg_access.cap.cap_next % 4 == 0); + + /* Fix up device cfg field length. */ + dev->config.device.length = len; + + /* The rest is the same as the no-config case */ + no_device_config(dev); +} + +static void init_cap(struct virtio_pci_cap *cap, size_t caplen, int type, + size_t bar_offset, size_t bar_bytes, u8 next) +{ + cap->cap_vndr = PCI_CAP_ID_VNDR; + cap->cap_next = next; + cap->cap_len = caplen; + cap->cfg_type = type; + cap->bar = 0; + memset(cap->padding, 0, sizeof(cap->padding)); + cap->offset = bar_offset; + cap->length = bar_bytes; } /* - * This routine sets the configuration fields for an existing device's - * descriptor. It only works for the last device, but that's OK because that's - * how we use it. + * This sets up the pci_config structure, as defined in the virtio 1.0 + * standard (and PCI standard). */ -static void set_config(struct device *dev, unsigned len, const void *conf) +static void init_pci_config(struct pci_config *pci, u16 type, + u8 class, u8 subclass) { - /* Check we haven't overflowed our single page. */ - if (device_config(dev) + len > devices.descpage + getpagesize()) - errx(1, "Too many devices"); + size_t bar_offset, bar_len; + + /* + * 4.1.4.4.1: + * + * The device MUST either present notify_off_multiplier as an even + * power of 2, or present notify_off_multiplier as 0. + * + * 2.1.2: + * + * The device MUST initialize device status to 0 upon reset. + */ + memset(pci, 0, sizeof(*pci)); + + /* 4.1.2.1: Devices MUST have the PCI Vendor ID 0x1AF4 */ + pci->vendor_id = 0x1AF4; + /* 4.1.2.1: ... PCI Device ID calculated by adding 0x1040 ... */ + pci->device_id = 0x1040 + type; + + /* + * PCI have specific codes for different types of devices. + * Linux doesn't care, but it's a good clue for people looking + * at the device. + */ + pci->class = class; + pci->subclass = subclass; + + /* + * 4.1.2.1: + * + * Non-transitional devices SHOULD have a PCI Revision ID of 1 or + * higher + */ + pci->revid = 1; + + /* + * 4.1.2.1: + * + * Non-transitional devices SHOULD have a PCI Subsystem Device ID of + * 0x40 or higher. + */ + pci->subsystem_device_id = 0x40; + + /* We use our dummy interrupt controller, and irq_line is the irq */ + pci->irq_line = devices.next_irq++; + pci->irq_pin = 0; + + /* Support for extended capabilities. */ + pci->status = (1 << 4); + + /* Link them in. */ + /* + * 4.1.4.3.1: + * + * The device MUST present at least one common configuration + * capability. + */ + pci->capabilities = offsetof(struct pci_config, common); + + /* 4.1.4.3.1 ... offset MUST be 4-byte aligned. */ + assert(pci->capabilities % 4 == 0); + + bar_offset = offsetof(struct virtio_pci_mmio, cfg); + bar_len = sizeof(((struct virtio_pci_mmio *)0)->cfg); + init_cap(&pci->common, sizeof(pci->common), VIRTIO_PCI_CAP_COMMON_CFG, + bar_offset, bar_len, + offsetof(struct pci_config, notify)); + + /* + * 4.1.4.4.1: + * + * The device MUST present at least one notification capability. + */ + bar_offset += bar_len; + bar_len = sizeof(((struct virtio_pci_mmio *)0)->notify); + + /* + * 4.1.4.4.1: + * + * The cap.offset MUST be 2-byte aligned. + */ + assert(pci->common.cap_next % 2 == 0); + + /* FIXME: Use a non-zero notify_off, for per-queue notification? */ + /* + * 4.1.4.4.1: + * + * The value cap.length presented by the device MUST be at least 2 and + * MUST be large enough to support queue notification offsets for all + * supported queues in all possible configurations. + */ + assert(bar_len >= 2); + + init_cap(&pci->notify.cap, sizeof(pci->notify), + VIRTIO_PCI_CAP_NOTIFY_CFG, + bar_offset, bar_len, + offsetof(struct pci_config, isr)); + + bar_offset += bar_len; + bar_len = sizeof(((struct virtio_pci_mmio *)0)->isr); + /* + * 4.1.4.5.1: + * + * The device MUST present at least one VIRTIO_PCI_CAP_ISR_CFG + * capability. + */ + init_cap(&pci->isr, sizeof(pci->isr), + VIRTIO_PCI_CAP_ISR_CFG, + bar_offset, bar_len, + offsetof(struct pci_config, cfg_access)); + + /* + * 4.1.4.7.1: + * + * The device MUST present at least one VIRTIO_PCI_CAP_PCI_CFG + * capability. + */ + /* This doesn't have any presence in the BAR */ + init_cap(&pci->cfg_access.cap, sizeof(pci->cfg_access), + VIRTIO_PCI_CAP_PCI_CFG, + 0, 0, 0); - /* Copy in the config information, and store the length. */ - memcpy(device_config(dev), conf, len); - dev->desc->config_len = len; + bar_offset += bar_len + sizeof(((struct virtio_pci_mmio *)0)->padding); + assert(bar_offset == sizeof(struct virtio_pci_mmio)); - /* Size must fit in config_len field (8 bits)! */ - assert(dev->desc->config_len == len); + /* + * This gets sewn in and length set in set_device_config(). + * Some devices don't have a device configuration interface, so + * we never expose this if we don't call set_device_config(). + */ + init_cap(&pci->device, sizeof(pci->device), VIRTIO_PCI_CAP_DEVICE_CFG, + bar_offset, 0, 0); } /* - * This routine does all the creation and setup of a new device, including - * calling new_dev_desc() to allocate the descriptor and device memory. We - * don't actually start the service threads until later. + * This routine does all the creation and setup of a new device, but we don't + * actually place the MMIO region until we know the size (if any) of the + * device-specific config. And we don't actually start the service threads + * until later. * * See what I mean about userspace being boring? */ -static struct device *new_device(const char *name, u16 type) +static struct device *new_pci_device(const char *name, u16 type, + u8 class, u8 subclass) { struct device *dev = malloc(sizeof(*dev)); /* Now we populate the fields one at a time. */ - dev->desc = new_dev_desc(type); dev->name = name; dev->vq = NULL; - dev->feature_len = 0; - dev->num_vq = 0; dev->running = false; - dev->next = NULL; + dev->wrote_features_ok = false; + dev->mmio_size = sizeof(struct virtio_pci_mmio); + dev->mmio = calloc(1, dev->mmio_size); + dev->features = (u64)1 << VIRTIO_F_VERSION_1; + dev->features_accepted = 0; - /* - * Append to device list. Prepending to a single-linked list is - * easier, but the user expects the devices to be arranged on the bus - * in command-line order. The first network device on the command line - * is eth0, the first block device /dev/vda, etc. - */ - if (devices.lastdev) - devices.lastdev->next = dev; - else - devices.dev = dev; - devices.lastdev = dev; + if (devices.device_num + 1 >= MAX_PCI_DEVICES) + errx(1, "Can only handle 31 PCI devices"); + + init_pci_config(&dev->config, type, class, subclass); + assert(!devices.pci[devices.device_num+1]); + devices.pci[++devices.device_num] = dev; return dev; } @@ -1324,6 +2651,7 @@ static struct device *new_device(const char *name, u16 type) static void setup_console(void) { struct device *dev; + struct virtio_console_config conf; /* If we can save the initial standard input settings... */ if (tcgetattr(STDIN_FILENO, &orig_term) == 0) { @@ -1336,7 +2664,7 @@ static void setup_console(void) tcsetattr(STDIN_FILENO, TCSANOW, &term); } - dev = new_device("console", VIRTIO_ID_CONSOLE); + dev = new_pci_device("console", VIRTIO_ID_CONSOLE, 0x07, 0x00); /* We store the console state in dev->priv, and initialize it. */ dev->priv = malloc(sizeof(struct console_abort)); @@ -1348,10 +2676,14 @@ static void setup_console(void) * stdin. When they put something in the output queue, we write it to * stdout. */ - add_virtqueue(dev, VIRTQUEUE_NUM, console_input); - add_virtqueue(dev, VIRTQUEUE_NUM, console_output); + add_pci_virtqueue(dev, console_input, "input"); + add_pci_virtqueue(dev, console_output, "output"); + + /* We need a configuration area for the emerg_wr early writes. */ + add_pci_feature(dev, VIRTIO_CONSOLE_F_EMERG_WRITE); + set_device_config(dev, &conf, sizeof(conf)); - verbose("device %u: console\n", ++devices.device_num); + verbose("device %u: console\n", devices.device_num); } /*:*/ @@ -1449,6 +2781,7 @@ static void configure_device(int fd, const char *tapif, u32 ipaddr) static int get_tun_device(char tapif[IFNAMSIZ]) { struct ifreq ifr; + int vnet_hdr_sz; int netfd; /* Start with this zeroed. Messy but sure. */ @@ -1476,6 +2809,18 @@ static int get_tun_device(char tapif[IFNAMSIZ]) */ ioctl(netfd, TUNSETNOCSUM, 1); + /* + * In virtio before 1.0 (aka legacy virtio), we added a 16-bit + * field at the end of the network header iff + * VIRTIO_NET_F_MRG_RXBUF was negotiated. For virtio 1.0, + * that became the norm, but we need to tell the tun device + * about our expanded header (which is called + * virtio_net_hdr_mrg_rxbuf in the legacy system). + */ + vnet_hdr_sz = sizeof(struct virtio_net_hdr_v1); + if (ioctl(netfd, TUNSETVNETHDRSZ, &vnet_hdr_sz) != 0) + err(1, "Setting tun header size to %u", vnet_hdr_sz); + memcpy(tapif, ifr.ifr_name, IFNAMSIZ); return netfd; } @@ -1499,12 +2844,12 @@ static void setup_tun_net(char *arg) net_info->tunfd = get_tun_device(tapif); /* First we create a new network device. */ - dev = new_device("net", VIRTIO_ID_NET); + dev = new_pci_device("net", VIRTIO_ID_NET, 0x02, 0x00); dev->priv = net_info; /* Network devices need a recv and a send queue, just like console. */ - add_virtqueue(dev, VIRTQUEUE_NUM, net_input); - add_virtqueue(dev, VIRTQUEUE_NUM, net_output); + add_pci_virtqueue(dev, net_input, "rx"); + add_pci_virtqueue(dev, net_output, "tx"); /* * We need a socket to perform the magic network ioctls to bring up the @@ -1524,7 +2869,7 @@ static void setup_tun_net(char *arg) p = strchr(arg, ':'); if (p) { str2mac(p+1, conf.mac); - add_feature(dev, VIRTIO_NET_F_MAC); + add_pci_feature(dev, VIRTIO_NET_F_MAC); *p = '\0'; } @@ -1538,25 +2883,21 @@ static void setup_tun_net(char *arg) configure_device(ipfd, tapif, ip); /* Expect Guest to handle everything except UFO */ - add_feature(dev, VIRTIO_NET_F_CSUM); - add_feature(dev, VIRTIO_NET_F_GUEST_CSUM); - add_feature(dev, VIRTIO_NET_F_GUEST_TSO4); - add_feature(dev, VIRTIO_NET_F_GUEST_TSO6); - add_feature(dev, VIRTIO_NET_F_GUEST_ECN); - add_feature(dev, VIRTIO_NET_F_HOST_TSO4); - add_feature(dev, VIRTIO_NET_F_HOST_TSO6); - add_feature(dev, VIRTIO_NET_F_HOST_ECN); + add_pci_feature(dev, VIRTIO_NET_F_CSUM); + add_pci_feature(dev, VIRTIO_NET_F_GUEST_CSUM); + add_pci_feature(dev, VIRTIO_NET_F_GUEST_TSO4); + add_pci_feature(dev, VIRTIO_NET_F_GUEST_TSO6); + add_pci_feature(dev, VIRTIO_NET_F_GUEST_ECN); + add_pci_feature(dev, VIRTIO_NET_F_HOST_TSO4); + add_pci_feature(dev, VIRTIO_NET_F_HOST_TSO6); + add_pci_feature(dev, VIRTIO_NET_F_HOST_ECN); /* We handle indirect ring entries */ - add_feature(dev, VIRTIO_RING_F_INDIRECT_DESC); - /* We're compliant with the damn spec. */ - add_feature(dev, VIRTIO_F_ANY_LAYOUT); - set_config(dev, sizeof(conf), &conf); + add_pci_feature(dev, VIRTIO_RING_F_INDIRECT_DESC); + set_device_config(dev, &conf, sizeof(conf)); /* We don't need the socket any more; setup is done. */ close(ipfd); - devices.device_num++; - if (bridging) verbose("device %u: tun %s attached to bridge: %s\n", devices.device_num, tapif, arg); @@ -1607,7 +2948,7 @@ static void blk_request(struct virtqueue *vq) head = wait_for_vq_desc(vq, iov, &out_num, &in_num); /* Copy the output header from the front of the iov (adjusts iov) */ - iov_consume(iov, out_num, &out, sizeof(out)); + iov_consume(vq->dev, iov, out_num, &out, sizeof(out)); /* Find and trim end of iov input array, for our status byte. */ in = NULL; @@ -1619,7 +2960,7 @@ static void blk_request(struct virtqueue *vq) } } if (!in) - errx(1, "Bad virtblk cmd with no room for status"); + bad_driver_vq(vq, "Bad virtblk cmd with no room for status"); /* * For historical reasons, block operations are expressed in 512 byte @@ -1627,15 +2968,7 @@ static void blk_request(struct virtqueue *vq) */ off = out.sector * 512; - /* - * In general the virtio block driver is allowed to try SCSI commands. - * It'd be nice if we supported eject, for example, but we don't. - */ - if (out.type & VIRTIO_BLK_T_SCSI_CMD) { - fprintf(stderr, "Scsi commands unsupported\n"); - *in = VIRTIO_BLK_S_UNSUPP; - wlen = sizeof(*in); - } else if (out.type & VIRTIO_BLK_T_OUT) { + if (out.type & VIRTIO_BLK_T_OUT) { /* * Write * @@ -1657,7 +2990,7 @@ static void blk_request(struct virtqueue *vq) /* Trim it back to the correct length */ ftruncate64(vblk->fd, vblk->len); /* Die, bad Guest, die. */ - errx(1, "Write past end %llu+%u", off, ret); + bad_driver_vq(vq, "Write past end %llu+%u", off, ret); } wlen = sizeof(*in); @@ -1699,11 +3032,11 @@ static void setup_block_file(const char *filename) struct vblk_info *vblk; struct virtio_blk_config conf; - /* Creat the device. */ - dev = new_device("block", VIRTIO_ID_BLOCK); + /* Create the device. */ + dev = new_pci_device("block", VIRTIO_ID_BLOCK, 0x01, 0x80); /* The device has one virtqueue, where the Guest places requests. */ - add_virtqueue(dev, VIRTQUEUE_NUM, blk_request); + add_pci_virtqueue(dev, blk_request, "request"); /* Allocate the room for our own bookkeeping */ vblk = dev->priv = malloc(sizeof(*vblk)); @@ -1712,9 +3045,6 @@ static void setup_block_file(const char *filename) vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE); vblk->len = lseek64(vblk->fd, 0, SEEK_END); - /* We support FLUSH. */ - add_feature(dev, VIRTIO_BLK_F_FLUSH); - /* Tell Guest how many sectors this device has. */ conf.capacity = cpu_to_le64(vblk->len / 512); @@ -1722,20 +3052,19 @@ static void setup_block_file(const char *filename) * Tell Guest not to put in too many descriptors at once: two are used * for the in and out elements. */ - add_feature(dev, VIRTIO_BLK_F_SEG_MAX); + add_pci_feature(dev, VIRTIO_BLK_F_SEG_MAX); conf.seg_max = cpu_to_le32(VIRTQUEUE_NUM - 2); - /* Don't try to put whole struct: we have 8 bit limit. */ - set_config(dev, offsetof(struct virtio_blk_config, geometry), &conf); + set_device_config(dev, &conf, sizeof(struct virtio_blk_config)); verbose("device %u: virtblock %llu sectors\n", - ++devices.device_num, le64_to_cpu(conf.capacity)); + devices.device_num, le64_to_cpu(conf.capacity)); } /*L:211 - * Our random number generator device reads from /dev/random into the Guest's + * Our random number generator device reads from /dev/urandom into the Guest's * input buffers. The usual case is that the Guest doesn't want random numbers - * and so has no buffers although /dev/random is still readable, whereas + * and so has no buffers although /dev/urandom is still readable, whereas * console is the reverse. * * The same logic applies, however. @@ -1754,7 +3083,7 @@ static void rng_input(struct virtqueue *vq) /* First we need a buffer from the Guests's virtqueue. */ head = wait_for_vq_desc(vq, iov, &out_num, &in_num); if (out_num) - errx(1, "Output buffers in rng?"); + bad_driver_vq(vq, "Output buffers in rng?"); /* * Just like the console write, we loop to cover the whole iovec. @@ -1763,8 +3092,8 @@ static void rng_input(struct virtqueue *vq) while (!iov_empty(iov, in_num)) { len = readv(rng_info->rfd, iov, in_num); if (len <= 0) - err(1, "Read from /dev/random gave %i", len); - iov_consume(iov, in_num, NULL, len); + err(1, "Read from /dev/urandom gave %i", len); + iov_consume(vq->dev, iov, in_num, NULL, len); totlen += len; } @@ -1780,17 +3109,20 @@ static void setup_rng(void) struct device *dev; struct rng_info *rng_info = malloc(sizeof(*rng_info)); - /* Our device's privat info simply contains the /dev/random fd. */ - rng_info->rfd = open_or_die("/dev/random", O_RDONLY); + /* Our device's private info simply contains the /dev/urandom fd. */ + rng_info->rfd = open_or_die("/dev/urandom", O_RDONLY); /* Create the new device. */ - dev = new_device("rng", VIRTIO_ID_RNG); + dev = new_pci_device("rng", VIRTIO_ID_RNG, 0xff, 0); dev->priv = rng_info; /* The device has one virtqueue, where the Guest places inbufs. */ - add_virtqueue(dev, VIRTQUEUE_NUM, rng_input); + add_pci_virtqueue(dev, rng_input, "input"); - verbose("device %u: rng\n", devices.device_num++); + /* We don't have any configuration space */ + no_device_config(dev); + + verbose("device %u: rng\n", devices.device_num); } /* That's the end of device setup. */ @@ -1820,17 +3152,23 @@ static void __attribute__((noreturn)) restart_guest(void) static void __attribute__((noreturn)) run_guest(void) { for (;;) { - unsigned long notify_addr; + struct lguest_pending notify; int readval; /* We read from the /dev/lguest device to run the Guest. */ - readval = pread(lguest_fd, ¬ify_addr, - sizeof(notify_addr), cpu_id); - - /* One unsigned long means the Guest did HCALL_NOTIFY */ - if (readval == sizeof(notify_addr)) { - verbose("Notify on address %#lx\n", notify_addr); - handle_output(notify_addr); + readval = pread(lguest_fd, ¬ify, sizeof(notify), cpu_id); + if (readval == sizeof(notify)) { + if (notify.trap == 13) { + verbose("Emulating instruction at %#x\n", + getreg(eip)); + emulate_insn(notify.insn); + } else if (notify.trap == 14) { + verbose("Emulating MMIO at %#x\n", + getreg(eip)); + emulate_mmio(notify.addr, notify.insn); + } else + errx(1, "Unknown trap %i addr %#08x\n", + notify.trap, notify.addr); /* ENOENT means the Guest died. Reading tells us why. */ } else if (errno == ENOENT) { char reason[1024] = { 0 }; @@ -1893,11 +3231,9 @@ int main(int argc, char *argv[]) main_args = argv; /* - * First we initialize the device list. We keep a pointer to the last - * device, and the next interrupt number to use for devices (1: - * remember that 0 is used by the timer). + * First we initialize the device list. We remember next interrupt + * number to use for devices (1: remember that 0 is used by the timer). */ - devices.lastdev = NULL; devices.next_irq = 1; /* We're CPU 0. In fact, that's the only CPU possible right now. */ @@ -1921,12 +3257,14 @@ int main(int argc, char *argv[]) guest_base = map_zeroed_pages(mem / getpagesize() + DEVICE_PAGES); guest_limit = mem; - guest_max = mem + DEVICE_PAGES*getpagesize(); - devices.descpage = get_pages(1); + guest_max = guest_mmio = mem + DEVICE_PAGES*getpagesize(); break; } } + /* We always have a console device, and it's always device 1. */ + setup_console(); + /* The options are fairly straight-forward */ while ((c = getopt_long(argc, argv, "v", opts, NULL)) != EOF) { switch (c) { @@ -1967,8 +3305,8 @@ int main(int argc, char *argv[]) verbose("Guest base is at %p\n", guest_base); - /* We always have a console device */ - setup_console(); + /* Initialize the (fake) PCI host bridge device. */ + init_pci_host_bridge(); /* Now we load the kernel */ start = load_kernel(open_or_die(argv[optind+1], O_RDONLY)); |
