On 29/01/2018 01:58, KarimAllah Ahmed wrote: > Add direct access to MSR_IA32_SPEC_CTRL for guests. Future intel processors > will use this MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1).
This has to be customizable per-VM (similar to the patches Amazon posted a while ago for UCODE_REV for example). It's not urgent anyway given that no processor has it yet. Thanks, Paolo > Cc: Asit Mallick <asit.k.mall...@intel.com> > Cc: Dave Hansen <dave.han...@intel.com> > Cc: Arjan Van De Ven <arjan.van.de....@intel.com> > Cc: Tim Chen <tim.c.c...@linux.intel.com> > Cc: Linus Torvalds <torva...@linux-foundation.org> > Cc: Andrea Arcangeli <aarca...@redhat.com> > Cc: Andi Kleen <a...@linux.intel.com> > Cc: Thomas Gleixner <t...@linutronix.de> > Cc: Dan Williams <dan.j.willi...@intel.com> > Cc: Jun Nakajima <jun.nakaj...@intel.com> > Cc: Andy Lutomirski <l...@kernel.org> > Cc: Greg KH <gre...@linuxfoundation.org> > Cc: Paolo Bonzini <pbonz...@redhat.com> > Cc: Ashok Raj <ashok....@intel.com> > Signed-off-by: KarimAllah Ahmed <karah...@amazon.de> > --- > arch/x86/kvm/cpuid.c | 4 +++- > arch/x86/kvm/vmx.c | 2 ++ > 2 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 32c0c14..2339b1a 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -71,6 +71,7 @@ u64 kvm_supported_xcr0(void) > #define KVM_CPUID_BIT_AVX512_4VNNIW 2 > #define KVM_CPUID_BIT_AVX512_4FMAPS 3 > #define KVM_CPUID_BIT_IBRS 26 > +#define KVM_CPUID_BIT_ARCH_CAPABILITIES 29 > #define KF(x) bit(KVM_CPUID_BIT_##x) > > int kvm_update_cpuid(struct kvm_vcpu *vcpu) > @@ -394,7 +395,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 > *entry, u32 function, > /* cpuid 7.0.edx*/ > const u32 kvm_cpuid_7_0_edx_x86_features = > KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS) | \ > - (boot_cpu_has(X86_FEATURE_IBRS) ? KF(IBRS) : 0); > + (boot_cpu_has(X86_FEATURE_IBRS) ? KF(IBRS) : 0) | \ > + (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES) ? > KF(ARCH_CAPABILITIES) : 0); > > /* all calls to cpuid_count() should be made on the same cpu */ > get_cpu(); > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index f82a44c..99cb761 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -9617,6 +9617,8 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm > *kvm, unsigned int id) > > if (boot_cpu_has(X86_FEATURE_IBPB)) > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PRED_CMD, > MSR_TYPE_RW); > + if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) > + vmx_disable_intercept_for_msr(msr_bitmap, > MSR_IA32_ARCH_CAPABILITIES, MSR_TYPE_R); > vmx_disable_intercept_for_msr(msr_bitmap, MSR_FS_BASE, MSR_TYPE_RW); > vmx_disable_intercept_for_msr(msr_bitmap, MSR_GS_BASE, MSR_TYPE_RW); > vmx_disable_intercept_for_msr(msr_bitmap, MSR_KERNEL_GS_BASE, > MSR_TYPE_RW); >
