Commit 1930e5dd authored by Oliver Upton's avatar Oliver Upton Committed by Paolo Bonzini
Browse files

kvm: x86: reads of restricted pv msrs should also result in #GP 



commit 66570e96 ("kvm: x86: only provide PV features if enabled in
guest's CPUID") only protects against disallowed guest writes to KVM
paravirtual msrs, leaving msr reads unchecked. Fix this by enforcing
KVM_CPUID_FEATURES for msr reads as well.

Fixes: 66570e96 ("kvm: x86: only provide PV features if enabled in guest's CPUID")
Signed-off-by: default avatarOliver Upton <oupton@google.com>
Reviewed-by: default avatarPeter Shier <pshier@google.com>
Message-Id: <20201027231044.655110-4-oupton@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent cc4cb017

arch/x86/kvm/x86.c

+34 −0
Original line number Diff line number Diff line
@@ -3465,29 +3465,63 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 
		msr_info->data = vcpu->arch.efer;

		break;

	case MSR_KVM_WALL_CLOCK:

		if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE))

			return 1;



		msr_info->data = vcpu->kvm->arch.wall_clock;

		break;

	case MSR_KVM_WALL_CLOCK_NEW:

		if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))

			return 1;



		msr_info->data = vcpu->kvm->arch.wall_clock;

		break;

	case MSR_KVM_SYSTEM_TIME:

		if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE))

			return 1;



		msr_info->data = vcpu->arch.time;

		break;

	case MSR_KVM_SYSTEM_TIME_NEW:

		if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))

			return 1;



		msr_info->data = vcpu->arch.time;

		break;

	case MSR_KVM_ASYNC_PF_EN:

		if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF))

			return 1;



		msr_info->data = vcpu->arch.apf.msr_en_val;

		break;

	case MSR_KVM_ASYNC_PF_INT:

		if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT))

			return 1;



		msr_info->data = vcpu->arch.apf.msr_int_val;

		break;

	case MSR_KVM_ASYNC_PF_ACK:

		if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF))

			return 1;



		msr_info->data = 0;

		break;

	case MSR_KVM_STEAL_TIME:

		if (!guest_pv_has(vcpu, KVM_FEATURE_STEAL_TIME))

			return 1;



		msr_info->data = vcpu->arch.st.msr_val;

		break;

	case MSR_KVM_PV_EOI_EN:

		if (!guest_pv_has(vcpu, KVM_FEATURE_PV_EOI))

			return 1;



		msr_info->data = vcpu->arch.pv_eoi.msr_val;

		break;

	case MSR_KVM_POLL_CONTROL:

		if (!guest_pv_has(vcpu, KVM_FEATURE_POLL_CONTROL))

			return 1;



		msr_info->data = vcpu->arch.msr_kvm_poll_control;

		break;

	case MSR_IA32_P5_MC_ADDR: