diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 5 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 73 | ||||
| -rw-r--r-- | include/uapi/linux/kvm.h | 6 |
4 files changed, 69 insertions, 18 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 0b8a9ea7a47b..88fce6ab4bbd 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1667,6 +1667,9 @@ extern u64 kvm_mce_cap_supported; int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type); int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, void *insn, int insn_len); +void __kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu, + u64 *data, u8 ndata); +void kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu); void kvm_enable_efer_bits(u64); bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 85ce11dac8fd..71f54d85f104 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5408,10 +5408,7 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) if (vmx->emulation_required && !vmx->rmode.vm86_active && vcpu->arch.exception.pending) { - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = - KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; + kvm_prepare_emulation_failure_exit(vcpu); return 0; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0377e61b8fc0..ac83d873d65b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7664,29 +7664,78 @@ void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip) } EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt); -static void prepare_emulation_failure_exit(struct kvm_vcpu *vcpu) +static void prepare_emulation_failure_exit(struct kvm_vcpu *vcpu, u64 *data, + u8 ndata, u8 *insn_bytes, u8 insn_size) { - struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; - u32 insn_size = ctxt->fetch.end - ctxt->fetch.data; struct kvm_run *run = vcpu->run; + u64 info[5]; + u8 info_start; + + /* + * Zero the whole array used to retrieve the exit info, as casting to + * u32 for select entries will leave some chunks uninitialized. + */ + memset(&info, 0, sizeof(info)); + + static_call(kvm_x86_get_exit_info)(vcpu, (u32 *)&info[0], &info[1], + &info[2], (u32 *)&info[3], + (u32 *)&info[4]); run->exit_reason = KVM_EXIT_INTERNAL_ERROR; run->emulation_failure.suberror = KVM_INTERNAL_ERROR_EMULATION; - run->emulation_failure.ndata = 0; + + /* + * There's currently space for 13 entries, but 5 are used for the exit + * reason and info. Restrict to 4 to reduce the maintenance burden + * when expanding kvm_run.emulation_failure in the future. + */ + if (WARN_ON_ONCE(ndata > 4)) + ndata = 4; + + /* Always include the flags as a 'data' entry. */ + info_start = 1; run->emulation_failure.flags = 0; if (insn_size) { - run->emulation_failure.ndata = 3; + BUILD_BUG_ON((sizeof(run->emulation_failure.insn_size) + + sizeof(run->emulation_failure.insn_bytes) != 16)); + info_start += 2; run->emulation_failure.flags |= KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES; run->emulation_failure.insn_size = insn_size; memset(run->emulation_failure.insn_bytes, 0x90, sizeof(run->emulation_failure.insn_bytes)); - memcpy(run->emulation_failure.insn_bytes, - ctxt->fetch.data, insn_size); + memcpy(run->emulation_failure.insn_bytes, insn_bytes, insn_size); } + + memcpy(&run->internal.data[info_start], info, sizeof(info)); + memcpy(&run->internal.data[info_start + ARRAY_SIZE(info)], data, + ndata * sizeof(data[0])); + + run->emulation_failure.ndata = info_start + ARRAY_SIZE(info) + ndata; } +static void prepare_emulation_ctxt_failure_exit(struct kvm_vcpu *vcpu) +{ + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; + + prepare_emulation_failure_exit(vcpu, NULL, 0, ctxt->fetch.data, + ctxt->fetch.end - ctxt->fetch.data); +} + +void __kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu, u64 *data, + u8 ndata) +{ + prepare_emulation_failure_exit(vcpu, data, ndata, NULL, 0); +} +EXPORT_SYMBOL_GPL(__kvm_prepare_emulation_failure_exit); + +void kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu) +{ + __kvm_prepare_emulation_failure_exit(vcpu, NULL, 0); +} +EXPORT_SYMBOL_GPL(kvm_prepare_emulation_failure_exit); + static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type) { struct kvm *kvm = vcpu->kvm; @@ -7701,16 +7750,14 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type) if (kvm->arch.exit_on_emulation_error || (emulation_type & EMULTYPE_SKIP)) { - prepare_emulation_failure_exit(vcpu); + prepare_emulation_ctxt_failure_exit(vcpu); return 0; } kvm_queue_exception(vcpu, UD_VECTOR); if (!is_guest_mode(vcpu) && static_call(kvm_x86_get_cpl)(vcpu) == 0) { - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; + prepare_emulation_ctxt_failure_exit(vcpu); return 0; } @@ -12336,9 +12383,7 @@ int kvm_handle_memory_failure(struct kvm_vcpu *vcpu, int r, * doesn't seem to be a real use-case behind such requests, just return * KVM_EXIT_INTERNAL_ERROR for now. */ - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; + kvm_prepare_emulation_failure_exit(vcpu); return 0; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 2c8aa8d4dac1..78f0719cc2a3 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -398,6 +398,11 @@ struct kvm_run { * "ndata" is correct, that new fields are enumerated in "flags", * and that each flag enumerates fields that are 64-bit aligned * and sized (so that ndata+internal.data[] is valid/accurate). + * + * Space beyond the defined fields may be used to store arbitrary + * debug information relating to the emulation failure. It is + * accounted for in "ndata" but the format is unspecified and is + * not represented in "flags". Any such information is *not* ABI! */ struct { __u32 suberror; @@ -409,6 +414,7 @@ struct kvm_run { __u8 insn_bytes[15]; }; }; + /* Arbitrary debug data may follow. */ } emulation_failure; /* KVM_EXIT_OSI */ struct { |