On Mon, Jun 22, 2015 at 9:05 AM, Denis V. Lunev <[email protected]> wrote:
> From: Andrey Smetanin <[email protected]>
>
> Previous patches allowes userspace to setup Hyper-V crash ctl msr.
> This msr should expose HV_X64_MSR_CRASH_CTL_NOTIFY value to Hyper-V
> guest to allow to send crash data. Unfortunately Hyper-V guest notifies
> hardware about crash by writing the same HV_X64_MSR_CRASH_CTL_NOTIFY value
> into crash ctl msr. Thus both user space and guest writes inside ctl msr the
> same value and this patch distingiush the moment of actual guest crash
> by checking host initiated value from msr info.
>
> Signed-off-by: Andrey Smetanin <[email protected]>
> Signed-off-by: Denis V. Lunev <[email protected]>
> CC: Paolo Bonzini <[email protected]>
> CC: Gleb Natapov <[email protected]>
> ---
> arch/x86/kvm/hyperv.c | 17 +++++++++--------
> arch/x86/kvm/hyperv.h | 2 +-
> arch/x86/kvm/x86.c | 3 ++-
> 3 files changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index 6b18015..f49502a 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/arch/x86/kvm/hyperv.c
> @@ -54,12 +54,12 @@ static int kvm_hv_msr_get_crash_ctl(struct kvm_vcpu
> *vcpu, u64 *pdata)
> return 0;
> }
>
> -static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data)
> +static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data, bool
> host)
> {
> struct kvm_arch_hyperv *hv = &vcpu->kvm->arch.hyperv;
>
> hv->hv_crash_ctl = data;
Should we allow hv_crash_ctl to be set if !host? It's a small detail,
but it doesn't seem like the guest should be able to disable crash
actions that userspace has enabled in hv_crash_ctl.
> - if ((data & HV_X64_MSR_CRASH_CTL_NOTIFY)) {
> + if ((data & HV_X64_MSR_CRASH_CTL_NOTIFY) && !host) {
> vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx "
> "0x%llx)\n", hv->hv_crash_param[0],
> hv->hv_crash_param[1],
> @@ -99,7 +99,8 @@ static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu,
> return 0;
> }
>
> -static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
> +static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu,
> + u32 msr, u64 data, bool host)
> {
> struct kvm *kvm = vcpu->kvm;
> struct kvm_arch_hyperv *hv = &kvm->arch.hyperv;
> @@ -156,7 +157,7 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32
> msr, u64 data)
> msr - HV_X64_MSR_CRASH_P0,
> data);
> case HV_X64_MSR_CRASH_CTL:
> - return kvm_hv_msr_set_crash_ctl(vcpu, data);
> + return kvm_hv_msr_set_crash_ctl(vcpu, data, host);
> default:
> vcpu_unimpl(vcpu, "Hyper-V unimpl wrmsr: 0x%x data 0x%llx\n",
> msr, data);
> @@ -165,7 +166,7 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32
> msr, u64 data)
> return 0;
> }
>
> -static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
> +static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool
> host)
> {
> struct kvm_vcpu_arch_hyperv *hv = &vcpu->arch.hyperv;
>
> @@ -278,17 +279,17 @@ static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32
> msr, u64 *pdata)
> return 0;
> }
>
> -int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
> +int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool
> host)
> {
> if (kvm_hv_msr_partition_wide(msr)) {
> int r;
>
> mutex_lock(&vcpu->kvm->lock);
> - r = kvm_hv_set_msr_pw(vcpu, msr, data);
> + r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
> mutex_unlock(&vcpu->kvm->lock);
> return r;
> } else
> - return kvm_hv_set_msr(vcpu, msr, data);
> + return kvm_hv_set_msr(vcpu, msr, data, host);
> }
>
> int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
> diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
> index 39aee93..dc49527 100644
> --- a/arch/x86/kvm/hyperv.h
> +++ b/arch/x86/kvm/hyperv.h
> @@ -22,7 +22,7 @@
> #ifndef __ARCH_X86_KVM_HYPERV_H__
> #define __ARCH_X86_KVM_HYPERV_H__
>
> -int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data);
> +int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool
> host);
> int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata);
>
> bool kvm_hv_hypercall_enabled(struct kvm *kvm);
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 111fa83..db4eecb 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2210,7 +2210,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
> msr_data *msr_info)
> case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
> case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
> case HV_X64_MSR_CRASH_CTL:
> - return kvm_hv_set_msr_common(vcpu, msr, data);
> + return kvm_hv_set_msr_common(vcpu, msr, data,
> + msr_info->host_initiated);
> break;
> case MSR_IA32_BBL_CR_CTL3:
> /* Drop writes to this legacy MSR -- see rdmsr
> --
> 1.9.1
>
> --
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