From b4128000e2c9b176a449d748dcb083c61d61cc6e Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov <vkuznets@redhat.com> Date: Fri, 21 May 2021 11:51:38 +0200 Subject: [PATCH] KVM: x86: hyper-v: Prepare to check access to Hyper-V MSRs Introduce hv_check_msr_access() to check if the particular MSR should be accessible by guest, this will be used with KVM_CAP_HYPERV_ENFORCE_CPUID mode. No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210521095204.2161214-5-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/hyperv.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 7e7928fc77ef..ab8dc23f05bf 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1202,12 +1202,21 @@ void kvm_hv_invalidate_tsc_page(struct kvm *kvm) mutex_unlock(&hv->hv_lock); } + +static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr) +{ + return true; +} + static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host) { struct kvm *kvm = vcpu->kvm; struct kvm_hv *hv = to_kvm_hv(kvm); + if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr))) + return 1; + switch (msr) { case HV_X64_MSR_GUEST_OS_ID: hv->hv_guest_os_id = data; @@ -1336,6 +1345,9 @@ static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host) { struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); + if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr))) + return 1; + switch (msr) { case HV_X64_MSR_VP_INDEX: { struct kvm_hv *hv = to_kvm_hv(vcpu->kvm); @@ -1450,6 +1462,9 @@ static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, struct kvm *kvm = vcpu->kvm; struct kvm_hv *hv = to_kvm_hv(kvm); + if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr))) + return 1; + switch (msr) { case HV_X64_MSR_GUEST_OS_ID: data = hv->hv_guest_os_id; @@ -1499,6 +1514,9 @@ static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, u64 data = 0; struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); + if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr))) + return 1; + switch (msr) { case HV_X64_MSR_VP_INDEX: data = hv_vcpu->vp_index; -- GitLab