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* virtio: fix out of range array accessMichael S. Tsirkin2010-02-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I have observed the following error on virtio-net module unload: ------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:858 __free_irq+0xa0/0x14c() Hardware name: Bochs Trying to free already-free IRQ 0 Modules linked in: virtio_net(-) virtio_blk virtio_pci virtio_ring virtio af_packet e1000 shpchp aacraid uhci_hcd ohci_hcd ehci_hcd [last unloaded: scsi_wait_scan] Pid: 1957, comm: rmmod Not tainted 2.6.33-rc8-vhost #24 Call Trace: [<ffffffff8103e195>] warn_slowpath_common+0x7c/0x94 [<ffffffff8103e204>] warn_slowpath_fmt+0x41/0x43 [<ffffffff810a7a36>] ? __free_pages+0x5a/0x70 [<ffffffff8107cc00>] __free_irq+0xa0/0x14c [<ffffffff8107cceb>] free_irq+0x3f/0x65 [<ffffffffa0081424>] vp_del_vqs+0x81/0xb1 [virtio_pci] [<ffffffffa0091d29>] virtnet_remove+0xda/0x10b [virtio_net] [<ffffffffa0075200>] virtio_dev_remove+0x22/0x4a [virtio] [<ffffffff812709ee>] __device_release_driver+0x66/0xac [<ffffffff81270ab7>] driver_detach+0x83/0xa9 [<ffffffff8126fc66>] bus_remove_driver+0x91/0xb4 [<ffffffff81270fcf>] driver_unregister+0x6c/0x74 [<ffffffffa0075418>] unregister_virtio_driver+0xe/0x10 [virtio] [<ffffffffa0091c4d>] fini+0x15/0x17 [virtio_net] [<ffffffff8106997b>] sys_delete_module+0x1c3/0x230 [<ffffffff81007465>] ? old_ich_force_enable_hpet+0x117/0x164 [<ffffffff813bb720>] ? do_page_fault+0x29c/0x2cc [<ffffffff81028e58>] sysenter_dispatch+0x7/0x27 ---[ end trace 15e88e4c576cc62b ]--- The bug is in virtio-pci: we use msix_vector as array index to get irq entry, but some vqs do not have a dedicated vector so this causes an out of bounds access. By chance, we seem to often get 0 value, which results in this error. Fix by verifying that vector is legal before using it as index. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Shirley Ma <xma@us.ibm.com> Acked-by: Amit Shah <amit.shah@redhat.com>
* virtio: Initialize vq->data entries to NULLAmit Shah2010-02-241-1/+4
| | | | | | | | | | | | vq operations depend on vq->data[i] being NULL to figure out if the vq entry is in use (since the previous patch). We have to initialize them to NULL to ensure we don't work with junk data and trigger false BUG_ONs. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Shirley Ma <xma@us.ibm.com>
* virtio: Add ability to detach unused buffers from vringsShirley Ma2010-02-241-0/+25
| | | | | | | | | | | There's currently no way for a virtio driver to ask for unused buffers, so it has to keep a list itself to reclaim them at shutdown. This is redundant, since virtio_ring stores that information. So add a new hook to do this. Signed-off-by: Shirley Ma <xma@us.ibm.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: use smp_XX barriers on SMPMichael S. Tsirkin2010-02-241-4/+22
| | | | | | | | | | | | | | | | | | | virtio is communicating with a virtual "device" that actually runs on another host processor. Thus SMP barriers can be used to control memory access ordering. Where possible, we should use SMP barriers which are more lightweight than mandatory barriers, because mandatory barriers also control MMIO effects on accesses through relaxed memory I/O windows (which virtio does not use) (compare specifically smp_rmb and rmb on x86_64). We can't just use smp_mb and friends though, because we must force memory ordering even if guest is UP since host could be running on another CPU, but SMP barriers are defined to barrier() in that configuration. So, for UP fall back to mandatory barriers instead. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: remove bogus barriers from DEBUG version of virtio_ring.cRusty Russell2010-02-241-2/+1
| | | | | | | | | | | | | | | | | | | With DEBUG defined, we add an ->in_use flag to detect if the caller invokes two virtio methods in parallel. The barriers attempt to ensure timely update of the ->in_use flag. But they're voodoo: if we need these barriers it implies that the calling code doesn't have sufficient synchronization to ensure the code paths aren't invoked at the same time anyway, and we want to detect it. Also, adding barriers changes timing, so turning on debug has more chance of hiding real problems. Thanks to MST for drawing my attention to this code... CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix balloon without VIRTIO_BALLOON_F_STATS_VQRusty Russell2010-02-241-0/+1
| | | | | | | | | | | | | | | | | | | | | When running under qemu-kvm-0.11.0: BUG: unable to handle kernel paging request at 56e58955 ... Process vballoon (pid: 1297, ti=c7976000 task=c70a6ca0 task.ti=c7 ... Call Trace: [<c88253a3>] ? balloon+0x1b3/0x440 [virtio_balloon] [<c041c2d7>] ? schedule+0x327/0x9d0 [<c88251f0>] ? balloon+0x0/0x440 [virtio_balloon] [<c014a2d4>] ? kthread+0x74/0x80 [<c014a260>] ? kthread+0x0/0x80 [<c0103b36>] ? kernel_thread_helper+0x6/0x30 need_stats_update should be zero-initialized. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Adam Litke <agl@us.ibm.com>
* virtio: Fix scheduling while atomic in virtio_balloon statsAdam Litke2010-02-241-4/+18
| | | | | | | | | | | | | | | | | | | | | | | | This is a fix for my earlier patch: "virtio: Add memory statistics reporting to the balloon driver (V4)". I discovered that all_vm_events() can sleep and therefore stats collection cannot be done in interrupt context. One solution is to handle the interrupt by noting that stats need to be collected and waking the existing vballoon kthread which will complete the work via stats_handle_request(). Rusty, is this a saner way of doing business? There is one issue that I would like a broader opinion on. In stats_request, I update vb->need_stats_update and then wake up the kthread. The kthread uses vb->need_stats_update as a condition variable. Do I need a memory barrier between the update and wake_up to ensure that my kthread sees the correct value? My testing suggests that it is not needed but I would like some confirmation from the experts. Signed-off-by: Adam Litke <agl@us.ibm.com> To: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@linux.vnet.ibm.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Add memory statistics reporting to the balloon driver (V4)Adam Litke2010-02-241-8/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space When using ballooning to manage overcommitted memory on a host, a system for guests to communicate their memory usage to the host can provide information that will minimize the impact of ballooning on the guests. The current method employs a daemon running in each guest that communicates memory statistics to a host daemon at a specified time interval. The host daemon aggregates this information and inflates and/or deflates balloons according to the level of host memory pressure. This approach is effective but overly complex since a daemon must be installed inside each guest and coordinated to communicate with the host. A simpler approach is to collect memory statistics in the virtio balloon driver and communicate them directly to the hypervisor. This patch enables the guest-side support by adding stats collection and reporting to the virtio balloon driver. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Anthony Liguori <anthony@codemonkey.ws> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor fixes)
* Add __devexit_p around reference to virtio_pci_removeJamie Lokier2010-02-241-1/+1
| | | | | | | | This is needed to compile with CONFIG_VIRTIO_PCI=y, because virtio_pci_remove is marked __devexit. Signed-off-by: Jamie Lokier <jamie@shareable.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix section mismatch warningsJeff Mahoney2010-01-161-3/+3
| | | | | | | | | | | | | | Fix fixes the following warnings by renaming the driver structures to be suffixed with _driver. WARNING: drivers/virtio/virtio_balloon.o(.data+0x88): Section mismatch in reference from the variable virtio_balloon to the function .devexit.text:virtballoon_remove() WARNING: drivers/char/hw_random/virtio-rng.o(.data+0x88): Section mismatch in reference from the variable virtio_rng to the function .devexit.text:virtrng_remove() Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio: order used ring after used index readMichael S. Tsirkin2009-10-291-0/+3
| | | | | | | | | | On SMP guests, reads from the ring might bypass used index reads. This causes guest crashes because host writes to used index to signal ring data readiness. Fix this by inserting rmb before used ring reads. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
* virtio-pci: fix per-vq MSI-X request logicMichael S. Tsirkin2009-10-291-12/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit f68d24082e22ccee3077d11aeb6dc5354f0ca7f1 in 2.6.32-rc1 broke requesting IRQs for per-VQ MSI-X vectors: - vector number was used instead of the vector itself - we try to request an IRQ for VQ which does not have a callback handler This is a regression that causes warnings in kernel log, potentially lower performance as we need to scan vq list, and might cause system failure if the interrupt requested is in fact needed by another system. This was not noticed earlier because in most cases we were falling back on shared interrupt for all vqs. The warnings often look like this: virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 28 for MSI/MSI-X IRQ handler type mismatch for IRQ 1 current handler: i8042 Pid: 2400, comm: modprobe Tainted: G W 2.6.32-rc3-11952-gf3ed8d8-dirty #1 Call Trace: [<ffffffff81072aed>] ? __setup_irq+0x299/0x304 [<ffffffff81072ff3>] ? request_threaded_irq+0x144/0x1c1 [<ffffffff813455af>] ? vring_interrupt+0x0/0x30 [<ffffffff81346598>] ? vp_try_to_find_vqs+0x583/0x5c7 [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] [<ffffffff81346609>] ? vp_find_vqs+0x2d/0x83 [<ffffffff81345d00>] ? vp_get+0x3c/0x4e [<ffffffffa0016373>] ? virtnet_probe+0x2f1/0x428 [virtio_net] [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] [<ffffffffa00150d8>] ? skb_xmit_done+0x0/0x39 [virtio_net] [<ffffffff8110ab92>] ? sysfs_do_create_link+0xcb/0x116 [<ffffffff81345cc2>] ? vp_get_status+0x14/0x16 [<ffffffff81345464>] ? virtio_dev_probe+0xa9/0xc8 [<ffffffff8122b11c>] ? driver_probe_device+0x8d/0x128 [<ffffffff8122b206>] ? __driver_attach+0x4f/0x6f [<ffffffff8122b1b7>] ? __driver_attach+0x0/0x6f [<ffffffff8122a9f9>] ? bus_for_each_dev+0x43/0x74 [<ffffffff8122a374>] ? bus_add_driver+0xea/0x22d [<ffffffff8122b4a3>] ? driver_register+0xa7/0x111 [<ffffffffa001a000>] ? init+0x0/0xc [virtio_net] [<ffffffff81009051>] ? do_one_initcall+0x50/0x148 [<ffffffff8106e117>] ? sys_init_module+0xc5/0x21a [<ffffffff8100af02>] ? system_call_fastpath+0x16/0x1b virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Reported-by: Shirley Ma <xma@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* move virtballoon_remove to .devexit.textUwe Kleine-König2009-10-221-1/+1
| | | | | | | | | | The function virtballoon_remove is used only wrapped by __devexit_p so define it using __devexit. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: let header files include virtio_ids.hChristian Borntraeger2009-10-221-1/+0
| | | | | | | | | | | | | | | | | | | | | Rusty, commit 3ca4f5ca73057a617f9444a91022d7127041970a virtio: add virtio IDs file moved all device IDs into a single file. While the change itself is a very good one, it can break userspace applications. For example if a userspace tool wanted to get the ID of virtio_net it used to include virtio_net.h. This does no longer work, since virtio_net.h does not include virtio_ids.h. This patch moves all "#include <linux/virtio_ids.h>" from the C files into the header files, making the header files compatible with the old ones. In addition, this patch exports virtio_ids.h to userspace. CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: add virtio IDs fileFernando Luis Vazquez Cao2009-09-231-0/+1
| | | | | | | | Virtio IDs are spread all over the tree which makes assigning new IDs bothersome. Putting them together should make the process less error-prone. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: make add_buf return capacity remainingRusty Russell2009-09-232-2/+6
| | | | | | | | | | This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
* virtio_pci: minor MSI-X cleanupsRusty Russell2009-09-231-55/+70
| | | | | | | | | | | | | 1) Rename vp_request_vectors to vp_request_msix_vectors, and take non-MSI-X case out to caller. 2) Comment weird pci_enable_msix API 3) Rename vp_find_vq to setup_vq. 4) Fix spaces to tabs 5) Make nvectors calc internal to vp_try_to_find_vqs() 6) Rename vector to msix_vector for more clarity. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com>
* virtio: refactor find_vqsMichael S. Tsirkin2009-07-301-93/+119
| | | | | | | | | | | | This refactors find_vqs, making it more readable and robust, and fixing two regressions from 2.6.30: - double free_irq causing BUG_ON on device removal - probe failure when vq can't be assigned to msi-x vector (reported on old host kernels) Tested-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: delete vq from listMichael S. Tsirkin2009-07-301-1/+5
| | | | | | | | | This makes delete vq the reverse of find vq. This is required to make it possible to retry find_vqs after a failure, otherwise the list gets corrupted. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix memory leak on device removalMichael S. Tsirkin2009-07-301-13/+15
| | | | | | | Make vp_free_vectors do the reverse of vq_request_vectors. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio-pci: correctly unregister root device on errorMark McLoughlin2009-07-171-1/+1
| | | | | | | | | If pci_register_driver() fails we're incorrectly unregistering the root device with device_unregister() rather than root_device_unregister(). Reported-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: enhance id_matching for virtio driversChristian Borntraeger2009-06-121-1/+1
| | | | | | | | | This patch allows a virtio driver to use VIRTIO_DEV_ANY_ID for the device id. This will be used by a test module that can be bound to any virtio device. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix id_matching for virtio driversChristian Borntraeger2009-06-121-1/+1
| | | | | | | | | | This bug never appeared, since all current virtio drivers use VIRTIO_DEV_ANY_ID for the vendor field. If a real vendor would be used, the check in virtio_id_match is wrong - it returns 0 if id->vendor == dev->id.vendor. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: indirect ring entries (VIRTIO_RING_F_INDIRECT_DESC)Mark McLoughlin2009-06-121-2/+73
| | | | | | | | | | | | | | | | | | Add a new feature flag for indirect ring entries. These are ring entries which point to a table of buffer descriptors. The idea here is to increase the ring capacity by allowing a larger effective ring size whereby the ring size dictates the number of requests that may be outstanding, rather than the size of those requests. This should be most effective in the case of block I/O where we can potentially benefit by concurrently dispatching a large number of large requests. Even in the simple case of single segment block requests, this results in a threefold increase in ring capacity. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: expose features in sysfsRusty Russell2009-06-121-0/+16
| | | | | | | Each device negotiates feature bits; expose these in sysfs to help diagnostics and debugging. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_pci: optional MSI-X supportMichael S. Tsirkin2009-06-121-19/+209
| | | | | | | | | | | | This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ whitespace, style)
* virtio_pci: split up vp_interruptMichael S. Tsirkin2009-06-121-19/+34
| | | | | | | | This reorganizes virtio-pci code in vp_interrupt slightly, so that it's easier to add per-vq MSI support on top. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: find_vqs/del_vqs virtio operationsMichael S. Tsirkin2009-06-122-23/+41
| | | | | | | | | This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations, and updates all drivers. This is needed for MSI support, because MSI needs to know the total number of vectors upfront. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
* virtio: add names to virtqueue struct, mapping from devices to queues.Rusty Russell2009-06-124-11/+27
| | | | | | | | | Add a linked list of all virtqueues for a virtio device: this helps for debugging and is also needed for upcoming interface change. Also, add a "name" field for clearer debug messages. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: meet virtio spec by finalizing features before using deviceRusty Russell2009-06-121-3/+4
| | | | | | | | | | | | | | Virtio devices are supposed to negotiate features before they start using the device, but the current code doesn't do this. This is because the driver's probe() function invariably has to add buffers to a virtqueue, or probe the disk (virtio_blk). This currently doesn't matter since no existing backend is strict about the feature negotiation. But it's possible to imagine a future feature which completely changes how a device operates: in this case, we'd need to acknowledge it before using the device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix suspend when using virtio_balloonMarcelo Tosatti2009-04-191-1/+2
| | | | | | | | | | Break out of wait_event_interruptible() if freezing has been requested, in the vballoon thread. Without this change vballoon refuses to stop and the system can't suspend. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
* virtio: more neatening of virtio_ring macros.Rusty Russell2009-03-301-3/+9
| | | | | | | | | | | | Impact: cleanup Roel Kluin drew attention to these macros with his patch: here I neaten them a little further: 1) Add a comment on what START_USE and END_USE are checking, 2) Brackets around _vq in BAD_RING, 3) Neaten formatting for START_USE so it's less than 80 cols. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix BAD_RING, START_US and END_USE macrosRoel Kluin2009-03-301-8/+8
| | | | | | | | | | | | Impact: cleanup fix BAD_RING, START_US and END_USE macros When these macros aren't called with a variable named vq as first argument, this would result in a build failure. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio-pci: do not oops on config change if driver not loadedMark McLoughlin2009-02-021-1/+1
| | | | | | | | | | | | | | | | | | The host really shouldn't be notifying us of config changes before the device status is VIRTIO_CONFIG_S_DRIVER or VIRTIO_CONFIG_S_DRIVER_OK. However, if we do happen to be interrupted while we're not attached to a driver, we really shouldn't oops. Prevent this simply by checking that device->driver is non-NULL before trying to notify the driver of config changes. Problem observed by doing a "set_link virtio.0 down" with QEMU before the net driver had been loaded. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio: do not statically allocate root deviceMark McLoughlin2009-01-061-10/+7
| | | | | | | | | | | | | | | | We shouldn't be statically allocating the root device object, so dynamically allocate it using root_device_register() instead. Also avoids this warning from 'rmmod virtio_pci': Device 'virtio-pci' does not have a release() function, it is broken and must be fixed Signed-off-by: Mark McLoughlin <markmc@redhat.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* virtio: add PCI device release() functionMark McLoughlin2008-12-301-6/+15
| | | | | | | | | | | | | | | | Add a release() function for virtio_pci devices so as to avoid: Device 'virtio0' does not have a release() function, it is broken and must be fixed Move the code to free the resources associated with the device from virtio_pci_remove() into this new function. virtio_pci_remove() now merely unregisters the device which should cause the final ref to be dropped and virtio_pci_release_dev() to be called. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Reported-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: avoid implicit use of Linux page size in balloon interfaceHollis Blanchard2008-12-301-2/+11
| | | | | | | | | Make the balloon interface always use 4K pages, and convert Linux pfns if necessary. This patch assumes that Linux's PAGE_SHIFT will never be less than 12. Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (modified)
* virtio: hand virtio ring alignment as argument to vring_new_virtqueueRusty Russell2008-12-302-3/+4
| | | | | | | | This allows each virtio user to hand in the alignment appropriate to their virtio_ring structures. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
* virtio: Don't use PAGE_SIZE for vring alignment in virtio_pci.Rusty Russell2008-12-301-2/+2
| | | | | | That doesn't work for non-4k guests which are now appearing. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Don't use PAGE_SIZE in virtio_pci.cRusty Russell2008-12-301-1/+1
| | | | | | | The virtio PCI devices don't depend on the guest page size. This matters now PowerPC virtio is gaining ground (they like 64k pages). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers2008-12-302-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is part of a larger patch series which will remove the "char bus_id[20]" name string from struct device. The device name is managed in the kobject anyway, and without any size limitation, and just needlessly copied into "struct device". To set and read the device name dev_name(dev) and dev_set_name(dev) must be used. If your code uses static kobjects, which it shouldn't do, "const char *init_name" can be used to statically provide the name the registered device should have. At registration time, the init_name field is cleared, to enforce the use of dev_name(dev) to access the device name at a later time. We need to get rid of all occurrences of bus_id in the entire tree to be able to enable the new interface. Please apply this patch, and possibly convert any remaining remaining occurrences of bus_id. We want to submit a patch to -next, which will remove bus_id from "struct device", to find the remaining pieces to convert, and finally switch over to the new api, which will remove the 20 bytes array and does no longer have a size limitation. Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio-pci queue allocation not page-alignedHollis Blanchard2008-12-301-5/+7
| | | | | | | | | | | kzalloc() does not guarantee page alignment, and in fact this broke when I enabled CONFIG_SLUB_DEBUG_ON. (Thanks to Anthony Liguori for spotting the missing kfree sub) Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (fixed kfree) Tested-by: Anthony Liguori <aliguori@us.ibm.com>
* virtio_balloon: fix towards_target when deflating balloonAnthony Liguori2008-08-261-1/+1
| | | | | | | | | | | | | | | | Both v and vb->num_pages are u32 and unsigned int respectively. If v is less than vb->num_pages (and it is, when deflating the balloon), the result is a very large 32-bit number. Since we're returning a s64, instead of getting the same negative number we desire, we get a very large positive number. This handles the case where v < vb->num_pages and ensures we get a small, negative, s64 as the result. Rusty: please push this for 2.6.27-rc4. It's probably appropriate for the stable tree too as it will cause an unexpected OOM when ballooning. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (simplified)
* virtio: Add transport feature handling stub for virtio_ring.Rusty Russell2008-07-252-0/+19
| | | | | | | | To prepare for virtio_ring transport feature bits, hook in a call in all the users to manipulate them. This currently just clears all the bits, since it doesn't understand any features. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Rename set_features to finalize_featuresRusty Russell2008-07-252-7/+8
| | | | | | | | | Rather than explicitly handing the features to the lower-level, we just hand the virtio_device and have it set the features. This make it clear that it has the chance to manipulate the features of the device at this point (and that all feature negotiation is already done). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Formally reserve bits 28-31 to be 'transport' features.Rusty Russell2008-07-251-0/+5
| | | | | | | We assign feature bits as required, but it makes sense to reserve some for the particular transport, rather than the particular device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Use bus_type probe and remove methodsMark McLoughlin2008-07-251-9/+9
| | | | | | | | | Hook up to the probe() and remove() methods in bus_type rather than device_driver. The latter has been preferred since 2.6.16. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: don't always force a notification when ring is fullRusty Russell2008-07-251-2/+5
| | | | | | | | | | | | | | | | | | | | | We force notification when the ring is full, even if the host has indicated it doesn't want to know. This seemed like a good idea at the time: if we fill the transmit ring, we should tell the host immediately. Unfortunately this logic also applies to the receiving ring, which is refilled constantly. We should introduce real notification thesholds to replace this logic. Meanwhile, removing the logic altogether breaks the heuristics which KVM uses, so we use a hack: only notify if there are outgoing parts of the new buffer. Here are the number of exits with lguest's crappy network implementation: Before: network xmit 7859051 recv 236420 After: network xmit 7858610 recv 118136 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Complete feature negotation before updating statusMark McLoughlin2008-06-151-1/+1
| | | | | | | | | | | | lguest (in rusty's use-tun-ringfd patch) assumes that the guest has updated its feature bits before setting its status to VIRTIO_CONFIG_S_DRIVER_OK. That's pretty reasonable, so let's make it so. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio: force callback on empty.Rusty Russell2008-05-301-7/+0
| | | | | | | | | | | | | | | | | | | | virtio allows drivers to suppress callbacks (ie. interrupts) for efficiency (no locking, it's just an optimization). There's a similar mechanism for the host to suppress notifications coming from the guest: in that case, we ignore the suppression if the ring is completely full. It turns out that life is simpler if the host similarly ignores callback suppression when the ring is completely empty: the network driver wants to free up old packets in a timely manner, and otherwise has to use a timer to poll. We have to remove the code which ignores interrupts when the driver has disabled them (again, it had no locking and hence was unreliable anyway). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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