diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2022-03-25 14:21:40 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-15 14:18:31 +0200 |
| commit | 9e24d03dd4fee589da500861967d9fd9c0e6276d (patch) | |
| tree | 9bd15e1d594b5d2dc781650a5f383aef5c7e8bde /arch | |
| parent | 1553126eccf4fad17afaeaed08db9e5944aa2d55 (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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index be92e8dccda3..ca66459a2e89 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -205,7 +205,7 @@ 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); @@ -251,6 +251,9 @@ 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; @@ -514,6 +517,11 @@ static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config, { union hv_stimer_config new_config = {.as_uint64 = config}, old_config = {.as_uint64 = stimer->config.as_uint64}; + struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); + struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); + + if (!synic->active && (!host || config)) + return 1; trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id, stimer->index, config, host); @@ -533,6 +541,12 @@ static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config, static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count, bool host) { + struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); + struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); + + if (!synic->active && (!host || count)) + return 1; + trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id, stimer->index, count, host); |