From e516cebb4f2b2057a5a421fea589079502acfff6 Mon Sep 17 00:00:00 2001 From: Andrey Smetanin Date: Wed, 16 Sep 2015 12:29:48 +0300 Subject: [PATCH] kvm/x86: Hyper-V HV_X64_MSR_RESET msr HV_X64_MSR_RESET msr is used by Hyper-V based Windows guest to reset guest VM by hypervisor. Necessary to support loading of winhv.sys in guest, which in turn is required to support Windows VMBus. Signed-off-by: Andrey Smetanin Reviewed-by: Roman Kagan Signed-off-by: Denis V. Lunev CC: Paolo Bonzini CC: Gleb Natapov Signed-off-by: Paolo Bonzini --- arch/x86/include/uapi/asm/hyperv.h | 3 +++ arch/x86/kvm/hyperv.c | 10 ++++++++++ arch/x86/kvm/x86.c | 7 +++++++ include/linux/kvm_host.h | 1 + 4 files changed, 21 insertions(+) diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h index f0412c50c47b..dab584bf7ddf 100644 --- a/arch/x86/include/uapi/asm/hyperv.h +++ b/arch/x86/include/uapi/asm/hyperv.h @@ -153,6 +153,9 @@ /* MSR used to provide vcpu index */ #define HV_X64_MSR_VP_INDEX 0x40000002 +/* MSR used to reset the guest OS. */ +#define HV_X64_MSR_RESET 0x40000003 + /* MSR used to read the per-partition time reference counter */ #define HV_X64_MSR_TIME_REF_COUNT 0x40000020 diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index a8160d2ae362..0ad11a232474 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -41,6 +41,7 @@ static bool kvm_hv_msr_partition_wide(u32 msr) case HV_X64_MSR_TIME_REF_COUNT: case HV_X64_MSR_CRASH_CTL: case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4: + case HV_X64_MSR_RESET: r = true; break; } @@ -163,6 +164,12 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data, data); case HV_X64_MSR_CRASH_CTL: return kvm_hv_msr_set_crash_ctl(vcpu, data, host); + case HV_X64_MSR_RESET: + if (data == 1) { + vcpu_debug(vcpu, "hyper-v reset requested\n"); + kvm_make_request(KVM_REQ_HV_RESET, vcpu); + } + break; default: vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n", msr, data); @@ -241,6 +248,9 @@ static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) pdata); case HV_X64_MSR_CRASH_CTL: return kvm_hv_msr_get_crash_ctl(vcpu, pdata); + case HV_X64_MSR_RESET: + data = 0; + break; default: vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr); return 1; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b90ad01c617d..297b36fa3b80 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -952,6 +952,7 @@ static u32 emulated_msrs[] = { HV_X64_MSR_TIME_REF_COUNT, HV_X64_MSR_REFERENCE_TSC, HV_X64_MSR_CRASH_P0, HV_X64_MSR_CRASH_P1, HV_X64_MSR_CRASH_P2, HV_X64_MSR_CRASH_P3, HV_X64_MSR_CRASH_P4, HV_X64_MSR_CRASH_CTL, + HV_X64_MSR_RESET, HV_X64_MSR_APIC_ASSIST_PAGE, MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME, MSR_KVM_PV_EOI_EN, @@ -6321,6 +6322,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) r = 0; goto out; } + if (kvm_check_request(KVM_REQ_HV_RESET, vcpu)) { + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; + vcpu->run->system_event.type = KVM_SYSTEM_EVENT_RESET; + r = 0; + goto out; + } } if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index d754f2d826e9..cd0ba2e931e1 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -141,6 +141,7 @@ static inline bool is_error_page(struct page *page) #define KVM_REQ_SMI 26 #define KVM_REQ_HV_CRASH 27 #define KVM_REQ_IOAPIC_EOI_EXIT 28 +#define KVM_REQ_HV_RESET 29 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1 -- GitLab