linux-kernel - [PATCH 14/30] KVM: x86: hyper-v: Honor HV_ACCESS_FREQUENCY

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Message-Id: <20210419160127.192712-15-vkuznets@redhat.com>
Date:   Mon, 19 Apr 2021 18:01:11 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Siddharth Chandrasekaran <sidcha@...zon.de>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 14/30] KVM: x86: hyper-v: Honor HV_ACCESS_FREQUENCY_MSRS privilege bit

HV_X64_MSR_TSC_FREQUENCY/HV_X64_MSR_APIC_FREQUENCY are only available to
guest when HV_ACCESS_FREQUENCY_MSRS bit is exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/kvm/hyperv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index a41ad21768ed..8821981e17d3 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1244,6 +1244,10 @@ static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
 		return hv_vcpu->cpuid_cache.features_eax &
 			HV_MSR_APIC_ACCESS_AVAILABLE;
 		break;
+	case HV_X64_MSR_TSC_FREQUENCY:
+	case HV_X64_MSR_APIC_FREQUENCY:
+		return hv_vcpu->cpuid_cache.features_eax &
+			HV_ACCESS_FREQUENCY_MSRS;
 	default:
 		break;
 	}
-- 
2.30.2