diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2022-03-25 14:21:40 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 14:40:38 +0200 |
| commit | 09c771c45c1243e295470225aaee726693fdc242 (patch) | |
| tree | 5dff772475210bd8c9c195a56a1270a68e3fb068 | |
| parent | aea4ffdcf30fc625d5775798ee9862957d0421cb (diff) | |
KVM: x86: Forbid VMM to set SYNIC/STIMER MSRs when SynIC wasn't activated
commit b1e34d325397a33d97d845e312d7cf2a8b646b44 upstream.
Setting non-zero values to SYNIC/STIMER MSRs activates certain features,
this should not happen when KVM_CAP_HYPERV_SYNIC{,2} was not activated.
Note, it would've been better to forbid writing anything to SYNIC/STIMER
MSRs, including zeroes, however, at least QEMU tries clearing
HV_X64_MSR_STIMER0_CONFIG without SynIC. HV_X64_MSR_EOM MSR is somewhat
'special' as writing zero there triggers an action, this also should not
happen when SynIC wasn't activated.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220325132140.25650-4-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 328f37e4fd3a..d806139377bc 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -207,7 +207,7 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic, struct kvm_vcpu *vcpu = synic_to_vcpu(synic); int ret; - if (!synic->active && !host) + if (!synic->active && (!host || data)) return 1; trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host); @@ -253,6 +253,9 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic, case HV_X64_MSR_EOM: { int i; + if (!synic->active) + break; + for (i = 0; i < ARRAY_SIZE(synic->sint); i++) kvm_hv_notify_acked_sint(vcpu, i); break; @@ -636,7 +639,7 @@ static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config, struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); - if (!synic->active && !host) + if (!synic->active && (!host || config)) return 1; trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id, @@ -660,7 +663,7 @@ static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count, struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); - if (!synic->active && !host) + if (!synic->active && (!host || count)) return 1; trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id, |