diff options
| -rw-r--r-- | arch/arm/include/asm/kvm_arm.h | 51 | ||||
| -rw-r--r-- | arch/arm/include/asm/kvm_host.h | 13 | ||||
| -rw-r--r-- | arch/arm/kernel/asm-offsets.c | 25 | ||||
| -rw-r--r-- | arch/arm/kvm/arm.c | 200 | ||||
| -rw-r--r-- | arch/arm/kvm/interrupts.S | 396 | ||||
| -rw-r--r-- | arch/arm/kvm/interrupts_head.S | 441 |
6 files changed, 1122 insertions, 4 deletions
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index d64b5250ad4e..c69936b1fc53 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -98,6 +98,18 @@ #define TTBCR_T0SZ 3 #define HTCR_MASK (TTBCR_T0SZ | TTBCR_IRGN0 | TTBCR_ORGN0 | TTBCR_SH0) +/* Hyp System Trap Register */ +#define HSTR_T(x) (1 << x) +#define HSTR_TTEE (1 << 16) +#define HSTR_TJDBX (1 << 17) + +/* Hyp Coprocessor Trap Register */ +#define HCPTR_TCP(x) (1 << x) +#define HCPTR_TCP_MASK (0x3fff) +#define HCPTR_TASE (1 << 15) +#define HCPTR_TTA (1 << 20) +#define HCPTR_TCPAC (1 << 31) + /* Hyp Debug Configuration Register bits */ #define HDCR_TDRA (1 << 11) #define HDCR_TDOSA (1 << 10) @@ -144,6 +156,45 @@ #else #define VTTBR_X (5 - KVM_T0SZ) #endif +#define VTTBR_BADDR_SHIFT (VTTBR_X - 1) +#define VTTBR_BADDR_MASK (((1LLU << (40 - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) +#define VTTBR_VMID_SHIFT (48LLU) +#define VTTBR_VMID_MASK (0xffLLU << VTTBR_VMID_SHIFT) + +/* Hyp Syndrome Register (HSR) bits */ +#define HSR_EC_SHIFT (26) +#define HSR_EC (0x3fU << HSR_EC_SHIFT) +#define HSR_IL (1U << 25) +#define HSR_ISS (HSR_IL - 1) +#define HSR_ISV_SHIFT (24) +#define HSR_ISV (1U << HSR_ISV_SHIFT) +#define HSR_FSC (0x3f) +#define HSR_FSC_TYPE (0x3c) +#define HSR_WNR (1 << 6) + +#define FSC_FAULT (0x04) +#define FSC_PERM (0x0c) + +/* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */ +#define HPFAR_MASK (~0xf) +#define HSR_EC_UNKNOWN (0x00) +#define HSR_EC_WFI (0x01) +#define HSR_EC_CP15_32 (0x03) +#define HSR_EC_CP15_64 (0x04) +#define HSR_EC_CP14_MR (0x05) +#define HSR_EC_CP14_LS (0x06) +#define HSR_EC_CP_0_13 (0x07) +#define HSR_EC_CP10_ID (0x08) +#define HSR_EC_JAZELLE (0x09) +#define HSR_EC_BXJ (0x0A) +#define HSR_EC_CP14_64 (0x0C) +#define HSR_EC_SVC_HYP (0x11) +#define HSR_EC_HVC (0x12) +#define HSR_EC_SMC (0x13) +#define HSR_EC_IABT (0x20) +#define HSR_EC_IABT_HYP (0x21) +#define HSR_EC_DABT (0x24) +#define HSR_EC_DABT_HYP (0x25) #endif /* __ARM_KVM_ARM_H__ */ diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 3636c7ea4eb2..7a121089c733 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -21,6 +21,7 @@ #include <asm/kvm.h> #include <asm/kvm_asm.h> +#include <asm/fpstate.h> #define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS #define KVM_MEMORY_SLOTS 32 @@ -85,6 +86,14 @@ struct kvm_vcpu_arch { u32 hxfar; /* Hyp Data/Inst Fault Address Register */ u32 hpfar; /* Hyp IPA Fault Address Register */ + /* Floating point registers (VFP and Advanced SIMD/NEON) */ + struct vfp_hard_struct vfp_guest; + struct vfp_hard_struct *vfp_host; + + /* + * Anything that is not used directly from assembly code goes + * here. + */ /* Interrupt related fields */ u32 irq_lines; /* IRQ and FIQ levels */ @@ -93,6 +102,9 @@ struct kvm_vcpu_arch { /* Cache some mmu pages needed inside spinlock regions */ struct kvm_mmu_memory_cache mmu_page_cache; + + /* Detect first run of a vcpu */ + bool has_run_once; }; struct kvm_vm_stat { @@ -112,6 +124,7 @@ struct kvm_one_reg; int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); u64 kvm_call_hyp(void *hypfn, ...); +void force_vm_exit(const cpumask_t *mask); #define KVM_ARCH_WANT_MMU_NOTIFIER struct kvm; diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index c985b481192c..c8b3272dfed1 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -13,6 +13,9 @@ #include <linux/sched.h> #include <linux/mm.h> #include <linux/dma-mapping.h> +#ifdef CONFIG_KVM_ARM_HOST +#include <linux/kvm_host.h> +#endif #include <asm/cacheflush.h> #include <asm/glue-df.h> #include <asm/glue-pf.h> @@ -146,5 +149,27 @@ int main(void) DEFINE(DMA_BIDIRECTIONAL, DMA_BIDIRECTIONAL); DEFINE(DMA_TO_DEVICE, DMA_TO_DEVICE); DEFINE(DMA_FROM_DEVICE, DMA_FROM_DEVICE); +#ifdef CONFIG_KVM_ARM_HOST + DEFINE(VCPU_KVM, offsetof(struct kvm_vcpu, kvm)); + DEFINE(VCPU_MIDR, offsetof(struct kvm_vcpu, arch.midr)); + DEFINE(VCPU_CP15, offsetof(struct kvm_vcpu, arch.cp15)); + DEFINE(VCPU_VFP_GUEST, offsetof(struct kvm_vcpu, arch.vfp_guest)); + DEFINE(VCPU_VFP_HOST, offsetof(struct kvm_vcpu, arch.vfp_host)); + DEFINE(VCPU_REGS, offsetof(struct kvm_vcpu, arch.regs)); + DEFINE(VCPU_USR_REGS, offsetof(struct kvm_vcpu, arch.regs.usr_regs)); + DEFINE(VCPU_SVC_REGS, offsetof(struct kvm_vcpu, arch.regs.svc_regs)); + DEFINE(VCPU_ABT_REGS, offsetof(struct kvm_vcpu, arch.regs.abt_regs)); + DEFINE(VCPU_UND_REGS, offsetof(struct kvm_vcpu, arch.regs.und_regs)); + DEFINE(VCPU_IRQ_REGS, offsetof(struct kvm_vcpu, arch.regs.irq_regs)); + DEFINE(VCPU_FIQ_REGS, offsetof(struct kvm_vcpu, arch.regs.fiq_regs)); + DEFINE(VCPU_PC, offsetof(struct kvm_vcpu, arch.regs.usr_regs.ARM_pc)); + DEFINE(VCPU_CPSR, offsetof(struct kvm_vcpu, arch.regs.usr_regs.ARM_cpsr)); + DEFINE(VCPU_IRQ_LINES, offsetof(struct kvm_vcpu, arch.irq_lines)); + DEFINE(VCPU_HSR, offsetof(struct kvm_vcpu, arch.hsr)); + DEFINE(VCPU_HxFAR, offsetof(struct kvm_vcpu, arch.hxfar)); + DEFINE(VCPU_HPFAR, offsetof(struct kvm_vcpu, arch.hpfar)); + DEFINE(VCPU_HYP_PC, offsetof(struct kvm_vcpu, arch.hyp_pc)); + DEFINE(KVM_VTTBR, offsetof(struct kvm, arch.vttbr)); +#endif return 0; } diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 2101152c3a4b..9e9fa4477884 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -40,6 +40,7 @@ #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> #include <asm/kvm_mmu.h> +#include <asm/kvm_emulate.h> #ifdef REQUIRES_VIRT __asm__(".arch_extension virt"); @@ -49,6 +50,10 @@ static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); static struct vfp_hard_struct __percpu *kvm_host_vfp_state; static unsigned long hyp_default_vectors; +/* The VMID used in the VTTBR */ +static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); +static u8 kvm_next_vmid; +static DEFINE_SPINLOCK(kvm_vmid_lock); int kvm_arch_hardware_enable(void *garbage) { @@ -276,6 +281,8 @@ int __attribute_const__ kvm_target_cpu(void) int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) { + /* Force users to call KVM_ARM_VCPU_INIT */ + vcpu->arch.target = -1; return 0; } @@ -286,6 +293,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { vcpu->cpu = cpu; + vcpu->arch.vfp_host = this_cpu_ptr(kvm_host_vfp_state); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) @@ -316,9 +324,199 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) return 0; } +/* Just ensure a guest exit from a particular CPU */ +static void exit_vm_noop(void *info) +{ +} + +void force_vm_exit(const cpumask_t *mask) +{ + smp_call_function_many(mask, exit_vm_noop, NULL, true); +} + +/** + * need_new_vmid_gen - check that the VMID is still valid + * @kvm: The VM's VMID to checkt + * + * return true if there is a new generation of VMIDs being used + * + * The hardware supports only 256 values with the value zero reserved for the + * host, so we check if an assigned value belongs to a previous generation, + * which which requires us to assign a new value. If we're the first to use a + * VMID for the new generation, we must flush necessary caches and TLBs on all + * CPUs. + */ +static bool need_new_vmid_gen(struct kvm *kvm) +{ + return unlikely(kvm->arch.vmid_gen != atomic64_read(&kvm_vmid_gen)); +} + +/** + * update_vttbr - Update the VTTBR with a valid VMID before the guest runs + * @kvm The guest that we are about to run + * + * Called from kvm_arch_vcpu_ioctl_run before entering the guest to ensure the + * VM has a valid VMID, otherwise assigns a new one and flushes corresponding + * caches and TLBs. + */ +static void update_vttbr(struct kvm *kvm) +{ + phys_addr_t pgd_phys; + u64 vmid; + + if (!need_new_vmid_gen(kvm)) + return; + + spin_lock(&kvm_vmid_lock); + + /* + * We need to re-check the vmid_gen here to ensure that if another vcpu + * already allocated a valid vmid for this vm, then this vcpu should + * use the same vmid. + */ + if (!need_new_vmid_gen(kvm)) { + spin_unlock(&kvm_vmid_lock); + return; + } + + /* First user of a new VMID generation? */ + if (unlikely(kvm_next_vmid == 0)) { + atomic64_inc(&kvm_vmid_gen); + kvm_next_vmid = 1; + + /* + * On SMP we know no other CPUs can use this CPU's or each + * other's VMID after force_vm_exit returns since the + * kvm_vmid_lock blocks them from reentry to the guest. + */ + force_vm_exit(cpu_all_mask); + /* + * Now broadcast TLB + ICACHE invalidation over the inner + * shareable domain to make sure all data structures are + * clean. + */ + kvm_call_hyp(__kvm_flush_vm_context); + } + + kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen); + kvm->arch.vmid = kvm_next_vmid; + kvm_next_vmid++; + + /* update vttbr to be used with the new vmid */ + pgd_phys = virt_to_phys(kvm->arch.pgd); + vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK; + kvm->arch.vttbr = pgd_phys & VTTBR_BADDR_MASK; + kvm->arch.vttbr |= vmid; + + spin_unlock(&kvm_vmid_lock); +} + +/* + * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on + * proper exit to QEMU. + */ +static int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, + int exception_index) +{ + run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + return 0; +} + +static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) +{ + if (likely(vcpu->arch.has_run_once)) + return 0; + + vcpu->arch.has_run_once = true; + return 0; +} + +/** + * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code + * @vcpu: The VCPU pointer + * @run: The kvm_run structure pointer used for userspace state exchange + * + * This function is called through the VCPU_RUN ioctl called from user space. It + * will execute VM code in a loop until the time slice for the process is used + * or some emulation is needed from user space in which case the function will + * return with return value 0 and with the kvm_run structure filled in with the + * required data for the requested emulation. + */ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) { - return -EINVAL; + int ret; + sigset_t sigsaved; + + /* Make sure they initialize the vcpu with KVM_ARM_VCPU_INIT */ + if (unlikely(vcpu->arch.target < 0)) + return -ENOEXEC; + + ret = kvm_vcpu_first_run_init(vcpu); + if (ret) + return ret; + + if (vcpu->sigset_active) + sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved); + + ret = 1; + run->exit_reason = KVM_EXIT_UNKNOWN; + while (ret > 0) { + /* + * Check conditions before entering the guest + */ + cond_resched(); + + update_vttbr(vcpu->kvm); + + local_irq_disable(); + + /* + * Re-check atomic conditions + */ + if (signal_pending(current)) { + ret = -EINTR; + run->exit_reason = KVM_EXIT_INTR; + } + + if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) { + local_irq_enable(); + continue; + } + + /************************************************************** + * Enter the guest + */ + trace_kvm_entry(*vcpu_pc(vcpu)); + kvm_guest_enter(); + vcpu->mode = IN_GUEST_MODE; + + ret = kvm_call_hyp(__kvm_vcpu_run, vcpu); + + vcpu->mode = OUTSIDE_GUEST_MODE; + kvm_guest_exit(); + trace_kvm_exit(*vcpu_pc(vcpu)); + /* + * We may have taken a host interrupt in HYP mode (ie + * while executing the guest). This interrupt is still + * pending, as we haven't serviced it yet! + * + * We're now back in SVC mode, with interrupts + * disabled. Enabling the interrupts now will have + * the effect of taking the interrupt again, in SVC + * mode this time. + */ + local_irq_enable(); + + /* + * Back from guest + *************************************************************/ + + ret = handle_exit(vcpu, run, ret); + } + + if (vcpu->sigset_active) + sigprocmask(SIG_SETMASK, &sigsaved, NULL); + return ret; } static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level) diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S index f701aff31e44..c5400d2e97ca 100644 --- a/arch/arm/kvm/interrupts.S +++ b/arch/arm/kvm/interrupts.S @@ -20,9 +20,12 @@ #include <linux/const.h> #include <asm/unified.h> #include <asm/page.h> +#include <asm/ptrace.h> #include <asm/asm-offsets.h> #include <asm/kvm_asm.h> #include <asm/kvm_arm.h> +#include <asm/vfpmacros.h> +#include "interrupts_head.S" .text @@ -31,23 +34,164 @@ __kvm_hyp_code_start: /******************************************************************** * Flush per-VMID TLBs + * + * void __kvm_tlb_flush_vmid(struct kvm *kvm); + * + * We rely on the hardware to broadcast the TLB invalidation to all CPUs + * inside the inner-shareable domain (which is the case for all v7 + * implementations). If we come across a non-IS SMP implementation, we'll + * have to use an IPI based mechanism. Until then, we stick to the simple + * hardware assisted version. */ ENTRY(__kvm_tlb_flush_vmid) + push {r2, r3} + + add r0, r0, #KVM_VTTBR + ldrd r2, r3, [r0] + mcrr p15, 6, r2, r3, c2 @ Write VTTBR + isb + mcr p15, 0, r0, c8, c3, 0 @ TLBIALLIS (rt ignored) + dsb + isb + mov r2, #0 + mov r3, #0 + mcrr p15, 6, r2, r3, c2 @ Back to VMID #0 + isb @ Not necessary if followed by eret + + pop {r2, r3} bx lr ENDPROC(__kvm_tlb_flush_vmid) /******************************************************************** - * Flush TLBs and instruction caches of current CPU for all VMIDs + * Flush TLBs and instruction caches of all CPUs inside the inner-shareable + * domain, for all VMIDs + * + * void __kvm_flush_vm_context(void); */ ENTRY(__kvm_flush_vm_context) + mov r0, #0 @ rn parameter for c15 flushes is SBZ + + /* Invalidate NS Non-Hyp TLB Inner Shareable (TLBIALLNSNHIS) */ + mcr p15, 4, r0, c8, c3, 4 + /* Invalidate instruction caches Inner Shareable (ICIALLUIS) */ + mcr p15, 0, r0, c7, c1, 0 + dsb + isb @ Not necessary if followed by eret + bx lr ENDPROC(__kvm_flush_vm_context) + /******************************************************************** * Hypervisor world-switch code + * + * + * int __kvm_vcpu_run(struct kvm_vcpu *vcpu) */ ENTRY(__kvm_vcpu_run) - bx lr + @ Save the vcpu pointer + mcr p15, 4, vcpu, c13, c0, 2 @ HTPIDR + + save_host_regs + + @ Store hardware CP15 state and load guest state + read_cp15_state store_to_vcpu = 0 + write_cp15_state read_from_vcpu = 1 + + @ If the host kernel has not been configured with VFPv3 support, + @ then it is safer if we deny guests from using it as well. +#ifdef CONFIG_VFPv3 + @ Set FPEXC_EN so the guest doesn't trap floating point instructions + VFPFMRX r2, FPEXC @ VMRS + push {r2} + orr r2, r2, #FPEXC_EN + VFPFMXR FPEXC, r2 @ VMSR +#endif + + @ Configure Hyp-role + configure_hyp_role vmentry + + @ Trap coprocessor CRx accesses + set_hstr vmentry + set_hcptr vmentry, (HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11)) + set_hdcr vmentry + + @ Write configured ID register into MIDR alias + ldr r1, [vcpu, #VCPU_MIDR] + mcr p15, 4, r1, c0, c0, 0 + + @ Write guest view of MPIDR into VMPIDR + ldr r1, [vcpu, #CP15_OFFSET(c0_MPIDR)] + mcr p15, 4, r1, c0, c0, 5 + + @ Set up guest memory translation + ldr r1, [vcpu, #VCPU_KVM] + add r1, r1, #KVM_VTTBR + ldrd r2, r3, [r1] + mcrr p15, 6, r2, r3, c2 @ Write VTTBR + + @ We're all done, just restore the GPRs and go to the guest + restore_guest_regs + clrex @ Clear exclusive monitor + eret + +__kvm_vcpu_return: + /* + * return convention: + * guest r0, r1, r2 saved on the stack + * r0: vcpu pointer + * r1: exception code + */ + save_guest_regs + + @ Set VMID == 0 + mov r2, #0 + mov r3, #0 + mcrr p15, 6, r2, r3, c2 @ Write VTTBR + + @ Don't trap coprocessor accesses for host kernel + set_hstr vmexit + set_hdcr vmexit + set_hcptr vmexit, (HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11)) + +#ifdef CONFIG_VFPv3 + @ Save floating point registers we if let guest use them. + tst r2, #(HCPTR_TCP(10) | HCPTR_TCP(11)) + bne after_vfp_restore + + @ Switch VFP/NEON hardware state to the host's + add r7, vcpu, #VCPU_VFP_GUEST + store_vfp_state r7 + add r7, vcpu, #VCPU_VFP_HOST + ldr r7, [r7] + restore_vfp_state r7 + +after_vfp_restore: + @ Restore FPEXC_EN which we clobbered on entry + pop {r2} + VFPFMXR FPEXC, r2 +#endif + + @ Reset Hyp-role + configure_hyp_role vmexit + + @ Let host read hardware MIDR + mrc p15, 0, r2, c0, c0, 0 + mcr p15, 4, r2, c0, c0, 0 + + @ Back to hardware MPIDR + mrc p15, 0, r2, c0, c0, 5 + mcr p15, 4, r2, c0, c0, 5 + + @ Store guest CP15 state and restore host state + read_cp15_state store_to_vcpu = 1 + write_cp15_state read_from_vcpu = 0 + + restore_host_regs + clrex @ Clear exclusive monitor + mov r0, r1 @ Return the return code + mov r1, #0 @ Clear upper bits in return value + bx lr @ return to IOCTL /******************************************************************** * Call function in Hyp mode @@ -77,12 +221,258 @@ ENTRY(kvm_call_hyp) /******************************************************************** * Hypervisor exception vector and handlers + * + * + * The KVM/ARM Hypervisor ABI is defined as follows: + * + * Entry to Hyp mode from the host kernel will happen _only_ when an HVC + * instruction is issued since all traps are disabled when running the host + * kernel as per the Hyp-mode initialization at boot time. + * + * HVC instructions cause a trap to the vector page + offset 0x18 (see hyp_hvc + * below) when the HVC instruction is called from SVC mode (i.e. a guest or the + * host kernel) and they cause a trap to the vector page + offset 0xc when HVC + * instructions are called from within Hyp-mode. + * + * Hyp-ABI: Calling HYP-mode functions from host (in SVC mode): + * Switching to Hyp mode is done through a simple HVC #0 instruction. The + * exception vector code will check that the HVC comes from VMID==0 and if + * so will push the necessary state (SPSR, lr_usr) on the Hyp stack. + * - r0 contains a pointer to a HYP function + * - r1, r2, and r3 contain arguments to the above function. + * - The HYP function will be called with its arguments in r0, r1 and r2. + * On HYP function return, we return directly to SVC. + * + * Note that the above is used to execute code in Hyp-mode from a host-kernel + * point of view, and is a different concept from performing a world-switch and + * executing guest code SVC mode (with a VMID != 0). */ +/* Handle undef, svc, pabt, or dabt by crashing with a user notice */ +.macro bad_exception exception_code, panic_str + push {r0-r2} + mrrc p15, 6, r0, r1, c2 @ Read VTTBR + lsr r1, r1, #16 + ands r1, r1, #0xff + beq 99f + + load_vcpu @ Load VCPU pointer + .if \exception_code == ARM_EXCEPTION_DATA_ABORT + mrc p15, 4, r2, c5, c2, 0 @ HSR + mrc p15, 4, r1, c6, c0, 0 @ HDFAR + str r2, [vcpu, #VCPU_HSR] + str r1, [vcpu, #VCPU_HxFAR] + .endif + .if \exception_code == ARM_EXCEPTION_PREF_ABORT + mrc p15, 4, r2, c5, c2, 0 @ HSR + mrc p15, 4, r1, c6, c0, 2 @ HIFAR + str r2, [vcpu, #VCPU_HSR] + str r1, [vcpu, #VCPU_HxFAR] + .endif + mov r1, #\exception_code + b __kvm_vcpu_return + + @ We were in the host already. Let's craft a panic-ing return to SVC. +99: mrs r2, cpsr + bic r2, r2, #MODE_MASK + orr r2, r2, #SVC_MODE +THUMB( orr r2, r2, #PSR_T_BIT ) + msr spsr_cxsf, r2 + mrs r1, ELR_hyp + ldr r2, =BSYM(panic) + msr ELR_hyp, r2 + ldr r0, =\panic_str + eret +.endm + + .text + .align 5 __kvm_hyp_vector: .globl __kvm_hyp_vector - nop + + @ Hyp-mode exception vector + W(b) hyp_reset + W(b) hyp_undef + W(b) hyp_svc + W(b) hyp_pabt + W(b) hyp_dabt + W(b) hyp_hvc + W(b) hyp_irq + W(b) hyp_fiq + + .align +hyp_reset: + b hyp_reset + + .align +hyp_undef: + bad_exception ARM_EXCEPTION_UNDEFINED, und_die_str + + .align +hyp_svc: + bad_exception ARM_EXCEPTION_HVC, svc_die_str + + .align +hyp_pabt: + bad_exception ARM_EXCEPTION_PREF_ABORT, pabt_die_str + + .align +hyp_dabt: + bad_exception ARM_EXCEPTION_DATA_ABORT, dabt_die_str + + .align +hyp_hvc: + /* + * Getting here is either becuase of a trap from a guest or from calling + * HVC from the host kernel, which means "switch to Hyp mode". + */ + push {r0, r1, r2} + + @ Check syndrome register + mrc p15, 4, r1, c5, c2, 0 @ HSR + lsr r0, r1, #HSR_EC_SHIFT +#ifdef CONFIG_VFPv3 + cmp r0, #HSR_EC_CP_0_13 + beq switch_to_guest_vfp +#endif + cmp r0, #HSR_EC_HVC + bne guest_trap @ Not HVC instr. + + /* + * Let's check if the HVC came from VMID 0 and allow simple + * switch to Hyp mode + */ + mrrc p15, 6, r0, r2, c2 + lsr r2, r2, #16 + and r2, r2, #0xff + cmp r2, #0 + bne guest_trap @ Guest called HVC + +host_switch_to_hyp: + pop {r0, r1, r2} + + push {lr} + mrs lr, SPSR + push {lr} + + mov lr, r0 + mov r0, r1 + mov r1, r2 + mov r2, r3 + +THUMB( orr lr, #1) + blx lr @ Call the HYP function + + pop {lr} + msr SPSR_csxf, lr + pop {lr} + eret + +guest_trap: + load_vcpu @ Load VCPU pointer to r0 + str r1, [vcpu, #VCPU_HSR] + + @ Check if we need the fault information + lsr r1, r1, #HSR_EC_SHIFT + cmp r1, #HSR_EC_IABT + mrceq p15, 4, r2, c6, c0, 2 @ HIFAR + beq 2f + cmp r1, #HSR_EC_DABT + bne 1f + mrc p15, 4, r2, c6, c0, 0 @ HDFAR + +2: str r2, [vcpu, #VCPU_HxFAR] + + /* + * B3.13.5 Reporting exceptions taken to the Non-secure PL2 mode: + * + * Abort on the stage 2 translation for a memory access from a + * Non-secure PL1 or PL0 mode: + * + * For any Access flag fault or Translation fault, and also for any + * Permission fault on the stage 2 translation of a memory access + * made as part of a translation table walk for a stage 1 translation, + * the HPFAR holds the IPA that caused the fault. Otherwise, the HPFAR + * is UNKNOWN. + */ + + /* Check for permission fault, and S1PTW */ + mrc p15, 4, r1, c5, c2, 0 @ HSR + and r0, r1, #HSR_FSC_TYPE + cmp r0, #FSC_PERM + tsteq r1, #(1 << 7) @ S1PTW + mrcne p15, 4, r2, c6, c0, 4 @ HPFAR + bne 3f + + /* Resolve IPA using the xFAR */ + mcr p15, 0, r2, c7, c8, 0 @ ATS1CPR + isb + mrrc p15, 0, r0, r1, c7 @ PAR + tst r0, #1 + bne 4f @ Failed translation + ubfx r2, r0, #12, #20 + lsl r2, r2, #4 + orr r2, r2, r1, lsl #24 + +3: load_vcpu @ Load VCPU pointer to r0 + str r2, [r0, #VCPU_HPFAR] + +1: mov r1, #ARM_EXCEPTION_HVC + b __kvm_vcpu_return + +4: pop {r0, r1, r2} @ Failed translation, return to guest + eret + +/* + * If VFPv3 support is not available, then we will not switch the VFP + * registers; however cp10 and cp11 accesses will still trap and fallback + * to the regular coprocessor emulation code, which currently will + * inject an undefined exception to the guest. + */ +#ifdef CONFIG_VFPv3 +switch_to_guest_vfp: + load_vcpu @ Load VCPU pointer to r0 + push {r3-r7} + + @ NEON/VFP used. Turn on VFP access. + set_hcptr vmexit, (HCPTR_TCP(10) | HCPTR_TCP(11)) + + @ Switch VFP/NEON hardware state to the guest's + add r7, r0, #VCPU_VFP_HOST + ldr r7, [r7] + store_vfp_state r7 + add r7, r0, #VCPU_VFP_GUEST + restore_vfp_state r7 + + pop {r3-r7} + pop {r0-r2} + eret +#endif + + .align +hyp_irq: + push {r0, r1, r2} + mov r1, #ARM_EXCEPTION_IRQ + load_vcpu @ Load VCPU pointer to r0 + b __kvm_vcpu_return + + .align +hyp_fiq: + b hyp_fiq + + .ltorg __kvm_hyp_code_end: .globl __kvm_hyp_code_end + + .section ".rodata" + +und_die_str: + .ascii "unexpected undefined exception in Hyp mode at: %#08x" +pabt_die_str: + .ascii "unexpected prefetch abort in Hyp mode at: %#08x" +dabt_die_str: + .ascii "unexpected data abort in Hyp mode at: %#08x" +svc_die_str: + .ascii "unexpected HVC/SVC trap in Hyp mode at: %#08x" diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S new file mode 100644 index 000000000000..6a95d341e9c5 --- /dev/null +++ b/arch/arm/kvm/interrupts_head.S @@ -0,0 +1,441 @@ +#define VCPU_USR_REG(_reg_nr) (VCPU_USR_REGS + (_reg_nr * 4)) +#define VCPU_USR_SP (VCPU_USR_REG(13)) +#define VCPU_USR_LR (VCPU_USR_REG(14)) +#define CP15_OFFSET(_cp15_reg_idx) (VCPU_CP15 + (_cp15_reg_idx * 4)) + +/* + * Many of these macros need to access the VCPU structure, which is always + * held in r0. These macros should never clobber r1, as it is used to hold the + * exception code on the return path (except of course the macro that switches + * all the registers before the final jump to the VM). + */ +vcpu .req r0 @ vcpu pointer always in r0 + +/* Clobbers {r2-r6} */ +.macro store_vfp_state vfp_base + @ The VFPFMRX and VFPFMXR macros are the VMRS and VMSR instructions + VFPFMRX r2, FPEXC + @ Make sure VFP is enabled so we can touch the registers. + orr r6, r2, #FPEXC_EN + VFPFMXR FPEXC, r6 + + VFPFMRX r3, FPSCR + tst r2, #FPEXC_EX @ Check for VFP Subarchitecture + beq 1f + @ If FPEXC_EX is 0, then FPINST/FPINST2 reads are upredictable, so + @ we only need to save them if FPEXC_EX is set. + VFPFMRX r4, FPINST + tst r2, #FPEXC_FP2V + VFPFMRX r5, FPINST2, ne @ vmrsne + bic r6, r2, #FPEXC_EX @ FPEXC_EX disable + VFPFMXR FPEXC, r6 +1: + VFPFSTMIA \vfp_base, r6 @ Save VFP registers + stm \vfp_base, {r2-r5} @ Save FPEXC, FPSCR, FPINST, FPINST2 +.endm + +/* Assume FPEXC_EN is on and FPEXC_EX is off, clobbers {r2-r6} */ +.macro restore_vfp_state vfp_base + VFPFLDMIA \vfp_base, r6 @ Load VFP registers + ldm \vfp_base, {r2-r5} @ Load FPEXC, FPSCR, FPINST, FPINST2 + + VFPFMXR FPSCR, r3 + tst r2, #FPEXC_EX @ Check for VFP Subarchitecture + beq 1f + VFPFMXR FPINST, r4 + tst r2, #FPEXC_FP2V + VFPFMXR FPINST2, r5, ne +1: + VFPFMXR FPEXC, r2 @ FPEXC (last, in case !EN) +.endm + +/* These are simply for the macros to work - value don't have meaning */ +.equ usr, 0 +.equ svc, 1 +.equ abt, 2 +.equ und, 3 +.equ irq, 4 +.equ fiq, 5 + +.macro push_host_regs_mode mode + mrs r2, SP_\mode + mrs r3, LR_\mode + mrs r4, SPSR_\mode + push {r2, r3, r4} +.endm + +/* + * Store all host persistent registers on the stack. + * Clobbers all registers, in all modes, except r0 and r1. + */ +.macro save_host_regs + /* Hyp regs. Only ELR_hyp (SPSR_hyp already saved) */ + mrs r2, ELR_hyp + push {r2} + + /* usr regs */ + push {r4-r12} @ r0-r3 are always clobbered + mrs r2, SP_usr + mov r3, lr + push {r2, r3} + + push_host_regs_mode svc + push_host_regs_mode abt + push_host_regs_mode und + push_host_regs_mode irq + + /* fiq regs */ + mrs r2, r8_fiq + mrs r3, r9_fiq + mrs r4, r10_fiq + mrs r5, r11_fiq + mrs r6, r12_fiq + mrs r7, SP_fiq + mrs r8, LR_fiq + mrs r9, SPSR_fiq + push {r2-r9} +.endm + +.macro pop_host_regs_mode mode + pop {r2, r3, r4} + msr SP_\mode, r2 + msr LR_\mode, r3 + msr SPSR_\mode, r4 +.endm + +/* + * Restore all host registers from the stack. + * Clobbers all registers, in all modes, except r0 and r1. + */ +.macro restore_host_regs + pop {r2-r9} + msr r8_fiq, r2 + msr r9_fiq, r3 + msr r10_fiq, r4 + msr r11_fiq, r5 + msr r12_fiq, r6 + msr SP_fiq, r7 + msr LR_fiq, r8 + msr SPSR_fiq, r9 + + pop_host_regs_mode irq + pop_host_regs_mode und + pop_host_regs_mode abt + pop_host_regs_mode svc + + pop {r2, r3} + msr SP_usr, r2 + mov lr, r3 + pop {r4-r12} + + pop {r2} + msr ELR_hyp, r2 +.endm + +/* + * Restore SP, LR and SPSR for a given mode. offset is the offset of + * this mode's registers from the VCPU base. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r1, r2, r3, r4. + */ +.macro restore_guest_regs_mode mode, offset + add r1, vcpu, \offset + ldm r1, {r2, r3, r4} + msr SP_\mode, r2 + msr LR_\mode, r3 + msr SPSR_\mode, r4 +.endm + +/* + * Restore all guest registers from the vcpu struct. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers *all* registers. + */ +.macro restore_guest_regs + restore_guest_regs_mode svc, #VCPU_SVC_REGS + restore_guest_regs_mode abt, #VCPU_ABT_REGS + restore_guest_regs_mode und, #VCPU_UND_REGS + restore_guest_regs_mode irq, #VCPU_IRQ_REGS + + add r1, vcpu, #VCPU_FIQ_REGS + ldm r1, {r2-r9} + msr r8_fiq, r2 + msr r9_fiq, r3 + msr r10_fiq, r4 + msr r11_fiq, r5 + msr r12_fiq, r6 + msr SP_fiq, r7 + msr LR_fiq, r8 + msr SPSR_fiq, r9 + + @ Load return state + ldr r2, [vcpu, #VCPU_PC] + ldr r3, [vcpu, #VCPU_CPSR] + msr ELR_hyp, r2 + msr SPSR_cxsf, r3 + + @ Load user registers + ldr r2, [vcpu, #VCPU_USR_SP] + ldr r3, [vcpu, #VCPU_USR_LR] + msr SP_usr, r2 + mov lr, r3 + add vcpu, vcpu, #(VCPU_USR_REGS) + ldm vcpu, {r0-r12} +.endm + +/* + * Save SP, LR and SPSR for a given mode. offset is the offset of + * this mode's registers from the VCPU base. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r2, r3, r4, r5. + */ +.macro save_guest_regs_mode mode, offset + add r2, vcpu, \offset + mrs r3, SP_\mode + mrs r4, LR_\mode + mrs r5, SPSR_\mode + stm r2, {r3, r4, r5} +.endm + +/* + * Save all guest registers to the vcpu struct + * Expects guest's r0, r1, r2 on the stack. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r2, r3, r4, r5. + */ +.macro save_guest_regs + @ Store usr registers + add r2, vcpu, #VCPU_USR_REG(3) + stm r2, {r3-r12} + add r2, vcpu, #VCPU_USR_REG(0) + pop {r3, r4, r5} @ r0, r1, r2 + stm r2, {r3, r4, r5} + mrs r2, SP_usr + mov r3, lr + str r2, [vcpu, #VCPU_USR_SP] + str r3, [vcpu, #VCPU_USR_LR] + + @ Store return state + mrs r2, ELR_hyp + mrs r3, spsr + str r2, [vcpu, #VCPU_PC] + str r3, [vcpu, #VCPU_CPSR] + + @ Store other guest registers + save_guest_regs_mode svc, #VCPU_SVC_REGS + save_guest_regs_mode abt, #VCPU_ABT_REGS + save_guest_regs_mode und, #VCPU_UND_REGS + save_guest_regs_mode irq, #VCPU_IRQ_REGS +.endm + +/* Reads cp15 registers from hardware and stores them in memory + * @store_to_vcpu: If 0, registers are written in-order to the stack, + * otherwise to the VCPU struct pointed to by vcpup + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r2 - r12 + */ +.macro read_cp15_state store_to_vcpu + mrc p15, 0, r2, c1, c0, 0 @ SCTLR + mrc p15, 0, r3, c1, c0, 2 @ CPACR + mrc p15, 0, r4, c2, c0, 2 @ TTBCR + mrc p15, 0, r5, c3, c0, 0 @ DACR + mrrc p15, 0, r6, r7, c2 @ TTBR 0 + mrrc p15, 1, r8, r9, c2 @ TTBR 1 + mrc p15, 0, r10, c10, c2, 0 @ PRRR + mrc p15, 0, r11, c10, c2, 1 @ NMRR + mrc p15, 2, r12, c0, c0, 0 @ CSSELR + + .if \store_to_vcpu == 0 + push {r2-r12} @ Push CP15 registers + .else + str r2, [vcpu, #CP15_OFFSET(c1_SCTLR)] + str r3, [vcpu, #CP15_OFFSET(c1_CPACR)] + str r4, [vcpu, #CP15_OFFSET(c2_TTBCR)] + str r5, [vcpu, #CP15_OFFSET(c3_DACR)] + add r2, vcpu, #CP15_OFFSET(c2_TTBR0) + strd r6, r7, [r2] + add r2, vcpu, #CP15_OFFSET(c2_TTBR1) + strd r8, r9, [r2] + str r10, [vcpu, #CP15_OFFSET(c10_PRRR)] + str r11, [vcpu, #CP15_OFFSET(c10_NMRR)] + str r12, [vcpu, #CP15_OFFSET(c0_CSSELR)] + .endif + + mrc p15, 0, r2, c13, c0, 1 @ CID + mrc p15, 0, r3, c13, c0, 2 @ TID_URW + mrc p15, 0, r4, c13, c0, 3 @ TID_URO + mrc p15, 0, r5, c13, c0, 4 @ TID_PRIV + mrc p15, 0, r6, c5, c0, 0 @ DFSR + mrc p15, 0, r7, c5, c0, 1 @ IFSR + mrc p15, 0, r8, c5, c1, 0 @ ADFSR + mrc p15, 0, r9, c5, c1, 1 @ AIFSR + mrc p15, 0, r10, c6, c0, 0 @ DFAR + mrc p15, 0, r11, c6, c0, 2 @ IFAR + mrc p15, 0, r12, c12, c0, 0 @ VBAR + + .if \store_to_vcpu == 0 + push {r2-r12} @ Push CP15 registers + .else + str r2, [vcpu, #CP15_OFFSET(c13_CID)] + str r3, [vcpu, #CP15_OFFSET(c13_TID_URW)] + str r4, [vcpu, #CP15_OFFSET(c13_TID_URO)] + str r5, [vcpu, #CP15_OFFSET(c13_TID_PRIV)] + str r6, [vcpu, #CP15_OFFSET(c5_DFSR)] + str r7, [vcpu, #CP15_OFFSET(c5_IFSR)] + str r8, [vcpu, #CP15_OFFSET(c5_ADFSR)] + str r9, [vcpu, #CP15_OFFSET(c5_AIFSR)] + str r10, [vcpu, #CP15_OFFSET(c6_DFAR)] + str r11, [vcpu, #CP15_OFFSET(c6_IFAR)] + str r12, [vcpu, #CP15_OFFSET(c12_VBAR)] + .endif +.endm + +/* + * Reads cp15 registers from memory and writes them to hardware + * @read_from_vcpu: If 0, registers are read in-order from the stack, + * otherwise from the VCPU struct pointed to by vcpup + * + * Assumes vcpu pointer in vcpu reg + */ +.macro write_cp15_state read_from_vcpu + .if \read_from_vcpu == 0 + pop {r2-r12} + .else + ldr r2, [vcpu, #CP15_OFFSET(c13_CID)] + ldr r3, [vcpu, #CP15_OFFSET(c13_TID_URW)] + ldr r4, [vcpu, #CP15_OFFSET(c13_TID_URO)] + ldr r5, [vcpu, #CP15_OFFSET(c13_TID_PRIV)] + ldr r6, [vcpu, #CP15_OFFSET(c5_DFSR)] + ldr r7, [vcpu, #CP15_OFFSET(c5_IFSR)] + ldr r8, [vcpu, #CP15_OFFSET(c5_ADFSR)] + ldr r9, [vcpu, #CP15_OFFSET(c5_AIFSR)] + ldr r10, [vcpu, #CP15_OFFSET(c6_DFAR)] + ldr r11, [vcpu, #CP15_OFFSET(c6_IFAR)] + ldr r12, [vcpu, #CP15_OFFSET(c12_VBAR)] + .endif + + mcr p15, 0, r2, c13, c0, 1 @ CID + mcr p15, 0, r3, c13, c0, 2 @ TID_URW + mcr p15, 0, r4, c13, c0, 3 @ TID_URO + mcr p15, 0, r5, c13, c0, 4 @ TID_PRIV + mcr p15, 0, r6, c5, c0, 0 @ DFSR + mcr p15, 0, r7, c5, c0, 1 @ IFSR + mcr p15, 0, r8, c5, c1, 0 @ ADFSR + mcr p15, 0, r9, c5, c1, 1 @ AIFSR + mcr p15, 0, r10, c6, c0, 0 @ DFAR + mcr p15, 0, r11, c6, c0, 2 @ IFAR + mcr p15, 0, r12, c12, c0, 0 @ VBAR + + .if \read_from_vcpu == 0 + pop {r2-r12} + .else + ldr r2, [vcpu, #CP15_OFFSET(c1_SCTLR)] + ldr r3, [vcpu, #CP15_OFFSET(c1_CPACR)] + ldr r4, [vcpu, #CP15_OFFSET(c2_TTBCR)] + ldr r5, [vcpu, #CP15_OFFSET(c3_DACR)] + add r12, vcpu, #CP15_OFFSET(c2_TTBR0) + ldrd r6, r7, [r12] + add r12, vcpu, #CP15_OFFSET(c2_TTBR1) + ldrd r8, r9, [r12] + ldr r10, [vcpu, #CP15_OFFSET(c10_PRRR)] + ldr r11, [vcpu, #CP15_OFFSET(c10_NMRR)] + ldr r12, [vcpu, #CP15_OFFSET(c0_CSSELR)] + .endif + + mcr p15, 0, r2, c1, c0, 0 @ SCTLR + mcr p15, 0, r3, c1, c0, 2 @ CPACR + mcr p15, 0, r4, c2, c0, 2 @ TTBCR + mcr p15, 0, r5, c3, c0, 0 @ DACR + mcrr p15, 0, r6, r7, c2 @ TTBR 0 + mcrr p15, 1, r8, r9, c2 @ TTBR 1 + mcr p15, 0, r10, c10, c2, 0 @ PRRR + mcr p15, 0, r11, c10, c2, 1 @ NMRR + mcr p15, 2, r12, c0, c0, 0 @ CSSELR +.endm + +/* + * Save the VGIC CPU state into memory + * + * Assumes vcpu pointer in vcpu reg + */ +.macro save_vgic_state +.endm + +/* + * Restore the VGIC CPU state from memory + * + * Assumes vcpu pointer in vcpu reg + */ +.macro restore_vgic_state +.endm + +.equ vmentry, 0 +.equ vmexit, 1 + +/* Configures the HSTR (Hyp System Trap Register) on entry/return + * (hardware reset value is 0) */ +.macro set_hstr operation + mrc p15, 4, r2, c1, c1, 3 + ldr r3, =HSTR_T(15) + .if \operation == vmentry + orr r2, r2, r3 @ Trap CR{15} + .else + bic r2, r2, r3 @ Don't trap any CRx accesses + .endif + mcr p15, 4, r2, c1, c1, 3 +.endm + +/* Configures the HCPTR (Hyp Coprocessor Trap Register) on entry/return + * (hardware reset value is 0). Keep previous value in r2. */ +.macro set_hcptr operation, mask + mrc p15, 4, r2, c1, c1, 2 + ldr r3, =\mask + .if \operation == vmentry + orr r3, r2, r3 @ Trap coproc-accesses defined in mask + .else + bic r3, r2, r3 @ Don't trap defined coproc-accesses + .endif + mcr p15, 4, r3, c1, c1, 2 +.endm + +/* Configures the HDCR (Hyp Debug Configuration Register) on entry/return + * (hardware reset value is 0) */ +.macro set_hdcr operation + mrc p15, 4, r2, c1, c1, 1 + ldr r3, =(HDCR_TPM|HDCR_TPMCR) + .if \operation == vmentry + orr r2, r2, r3 @ Trap some perfmon accesses + .else + bic r2, r2, r3 @ Don't trap any perfmon accesses + .endif + mcr p15, 4, r2, c1, c1, 1 +.endm + +/* Enable/Disable: stage-2 trans., trap interrupts, trap wfi, trap smc */ +.macro configure_hyp_role operation + mrc p15, 4, r2, c1, c1, 0 @ HCR + bic r2, r2, #HCR_VIRT_EXCP_MASK + ldr r3, =HCR_GUEST_MASK + .if \operation == vmentry + orr r2, r2, r3 + ldr r3, [vcpu, #VCPU_IRQ_LINES] + orr r2, r2, r3 + .else + bic r2, r2, r3 + .endif + mcr p15, 4, r2, c1, c1, 0 +.endm + +.macro load_vcpu + mrc p15, 4, vcpu, c13, c0, 2 @ HTPIDR +.endm |
