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| author | Paolo Bonzini <pbonzini@redhat.com> | 2018-07-26 13:01:52 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-08-06 17:32:01 +0200 |
| commit | 44883f01fe6ae436a8604c47d8435276fef369b0 (patch) | |
| tree | d2339b15742e5f66afb5ea7bf1e825710ac175dd /arch/x86/kvm/x86.c | |
| parent | cf81a7e580ac0d598d3e7e9c06864168b2b4073d (diff) | |
| download | linux-44883f01fe6ae436a8604c47d8435276fef369b0.tar.gz linux-44883f01fe6ae436a8604c47d8435276fef369b0.tar.bz2 linux-44883f01fe6ae436a8604c47d8435276fef369b0.zip | |
KVM: x86: ensure all MSRs can always be KVM_GET/SET_MSR'd
Some of the MSRs returned by GET_MSR_INDEX_LIST currently cannot be sent back
to KVM_GET_MSR and/or KVM_SET_MSR; either they can never be sent back, or you
they are only accepted under special conditions. This makes the API a pain to
use.
To avoid this pain, this patch makes it so that the result of the get-list
ioctl can always be used for host-initiated get and set. Since we don't have
a separate way to check for read-only MSRs, this means some Hyper-V MSRs are
ignored when written. Arguably they should not even be in the result of
GET_MSR_INDEX_LIST, but I am leaving there in case userspace is using the
outcome of GET_MSR_INDEX_LIST to derive the support for the corresponding
Hyper-V feature.
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2b812b3c5088..6f0fabdb2109 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2160,10 +2160,11 @@ static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vcpu->arch.mcg_status = data; break; case MSR_IA32_MCG_CTL: - if (!(mcg_cap & MCG_CTL_P)) + if (!(mcg_cap & MCG_CTL_P) && + (data || !msr_info->host_initiated)) return 1; if (data != 0 && data != ~(u64)0) - return -1; + return 1; vcpu->arch.mcg_ctl = data; break; default: @@ -2551,7 +2552,7 @@ int kvm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) } EXPORT_SYMBOL_GPL(kvm_get_msr); -static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) +static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host) { u64 data; u64 mcg_cap = vcpu->arch.mcg_cap; @@ -2566,7 +2567,7 @@ static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) data = vcpu->arch.mcg_cap; break; case MSR_IA32_MCG_CTL: - if (!(mcg_cap & MCG_CTL_P)) + if (!(mcg_cap & MCG_CTL_P) && !host) return 1; data = vcpu->arch.mcg_ctl; break; @@ -2699,7 +2700,8 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_MCG_CTL: case MSR_IA32_MCG_STATUS: case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1: - return get_msr_mce(vcpu, msr_info->index, &msr_info->data); + return get_msr_mce(vcpu, msr_info->index, &msr_info->data, + msr_info->host_initiated); case MSR_K7_CLK_CTL: /* * Provide expected ramp-up count for K7. All other @@ -2720,7 +2722,8 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case HV_X64_MSR_TSC_EMULATION_CONTROL: case HV_X64_MSR_TSC_EMULATION_STATUS: return kvm_hv_get_msr_common(vcpu, - msr_info->index, &msr_info->data); + msr_info->index, &msr_info->data, + msr_info->host_initiated); break; case MSR_IA32_BBL_CR_CTL3: /* This legacy MSR exists but isn't fully documented in current |