| Message ID | CANRm+CzvN5ypz=Y2moJQph36O5tpDbqzJtB2N_8Hm3guqWXYSg@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 27/02/2018 10:26, Wanpeng Li wrote: > 2018-02-27 16:38 GMT+08:00 Paolo Bonzini <pbonzini@redhat.com>: >> On 27/02/2018 03:35, Wanpeng Li wrote: >>> From: Wanpeng Li <wanpengli@tencent.com> >>> >>> Linux (among the others) has checks to make sure that certain features >>> aren't enabled on a certain family/model/stepping if the microcode version >>> isn't greater than or equal to a known good version. >>> >>> By exposing the real microcode version, we're preventing buggy guests that >>> don't check that they are running virtualized (i.e., they should trust the >>> hypervisor) from disabling features that are effectively not buggy. >>> >>> Suggested-by: Filippo Sironi <sironi@amazon.de> >>> Cc: Paolo Bonzini <pbonzini@redhat.com> >>> Cc: Radim Krčmář <rkrcmar@redhat.com> >>> Cc: Liran Alon <liran.alon@oracle.com> >>> Cc: Nadav Amit <nadav.amit@gmail.com> >>> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> >>> --- >>> v3 -> v4: >>> * add the shifts back >> >> Please wait for a review instead of pushing new versions continuously. >> Leaving the shifts means that MSR_IA32_UCODE_REV's bits 0-31 are zeroed >> even if KVM_SET_MSRS makes them nonzero. > > How about something like this? Yes, that's okay. Paolo
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 938d453..df6720f 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -507,6 +507,7 @@ struct kvm_vcpu_arch { u64 smi_count; bool tpr_access_reporting; u64 ia32_xss; + u64 microcode_version; /* * Paging state of the vcpu diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f874798..312f33f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1907,6 +1907,7 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) u32 dummy; u32 eax = 1; + vcpu->arch.microcode_version = 0x01000065; svm->spec_ctrl = 0; if (!init_event) { @@ -3962,9 +3963,6 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = svm->spec_ctrl; break; - case MSR_IA32_UCODE_REV: - msr_info->data = 0x01000065; - break; case MSR_F15H_IC_CFG: { int family, model; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9968906..2cdbea7 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5781,6 +5781,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) vmx->rmode.vm86_active = 0; vmx->spec_ctrl = 0; + vcpu->arch.microcode_version = 0x100000000ULL; vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val(); kvm_set_cr8(vcpu, 0); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d4985a9..7afffd3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1058,6 +1058,7 @@ static unsigned num_emulated_msrs; static u32 msr_based_features[] = { MSR_IA32_ARCH_CAPABILITIES, MSR_F10H_DECFG, + MSR_IA32_UCODE_REV, }; static unsigned int num_msr_based_features; @@ -1067,8 +1068,14 @@ static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data) struct kvm_msr_entry msr; msr.index = index; - if (kvm_x86_ops->get_msr_feature(&msr)) - return 1; + switch (msr.index) { + case MSR_IA32_UCODE_REV: + rdmsrl(msr.index, msr.data); + break; + default: + if (kvm_x86_ops->get_msr_feature(&msr)) + return 1; + } *data = msr.data;