diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0033-x86-KVM-VMX-Expose-SPEC_CTRL-Bit-2-to-the-guest.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0033-x86-KVM-VMX-Expose-SPEC_CTRL-Bit-2-to-the-guest.patch | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0033-x86-KVM-VMX-Expose-SPEC_CTRL-Bit-2-to-the-guest.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0033-x86-KVM-VMX-Expose-SPEC_CTRL-Bit-2-to-the-guest.patch new file mode 100644 index 00000000..743d2a90 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0033-x86-KVM-VMX-Expose-SPEC_CTRL-Bit-2-to-the-guest.patch @@ -0,0 +1,120 @@ +From 8f8f17abbbabcff7ebf353b62bbcfb414f83d77e Mon Sep 17 00:00:00 2001 +From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> +Date: Wed, 25 Apr 2018 22:04:25 -0400 +Subject: [PATCH 33/93] x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +commit da39556f66f5cfe8f9c989206974f1cb16ca5d7c upstream + +Expose the CPUID.7.EDX[31] bit to the guest, and also guard against various +combinations of SPEC_CTRL MSR values. + +The handling of the MSR (to take into account the host value of SPEC_CTRL +Bit(2)) is taken care of in patch: + + KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS + +Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Reviewed-by: Ingo Molnar <mingo@kernel.org> + +[dwmw2: Handle 4.9 guest CPUID differences, rename + guest_cpu_has_ibrs() → guest_cpu_has_spec_ctrl()] +Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kvm/cpuid.c | 2 +- + arch/x86/kvm/cpuid.h | 4 ++-- + arch/x86/kvm/svm.c | 4 ++-- + arch/x86/kvm/vmx.c | 6 +++--- + 4 files changed, 8 insertions(+), 8 deletions(-) + +diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c +index bcebe84..237e926 100644 +--- a/arch/x86/kvm/cpuid.c ++++ b/arch/x86/kvm/cpuid.c +@@ -382,7 +382,7 @@ 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 = +- F(SPEC_CTRL) | F(ARCH_CAPABILITIES); ++ F(SPEC_CTRL) | F(RDS) | F(ARCH_CAPABILITIES); + + /* all calls to cpuid_count() should be made on the same cpu */ + get_cpu(); +diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h +index 841e80d..39dd457 100644 +--- a/arch/x86/kvm/cpuid.h ++++ b/arch/x86/kvm/cpuid.h +@@ -163,7 +163,7 @@ static inline bool guest_cpuid_has_ibpb(struct kvm_vcpu *vcpu) + return best && (best->edx & bit(X86_FEATURE_SPEC_CTRL)); + } + +-static inline bool guest_cpuid_has_ibrs(struct kvm_vcpu *vcpu) ++static inline bool guest_cpuid_has_spec_ctrl(struct kvm_vcpu *vcpu) + { + struct kvm_cpuid_entry2 *best; + +@@ -171,7 +171,7 @@ static inline bool guest_cpuid_has_ibrs(struct kvm_vcpu *vcpu) + if (best && (best->ebx & bit(X86_FEATURE_IBRS))) + return true; + best = kvm_find_cpuid_entry(vcpu, 7, 0); +- return best && (best->edx & bit(X86_FEATURE_SPEC_CTRL)); ++ return best && (best->edx & (bit(X86_FEATURE_SPEC_CTRL) | bit(X86_FEATURE_RDS))); + } + + static inline bool guest_cpuid_has_arch_capabilities(struct kvm_vcpu *vcpu) +diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c +index a07579f..43736dd 100644 +--- a/arch/x86/kvm/svm.c ++++ b/arch/x86/kvm/svm.c +@@ -3540,7 +3540,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) + break; + case MSR_IA32_SPEC_CTRL: + if (!msr_info->host_initiated && +- !guest_cpuid_has_ibrs(vcpu)) ++ !guest_cpuid_has_spec_ctrl(vcpu)) + return 1; + + msr_info->data = svm->spec_ctrl; +@@ -3631,7 +3631,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) + break; + case MSR_IA32_SPEC_CTRL: + if (!msr->host_initiated && +- !guest_cpuid_has_ibrs(vcpu)) ++ !guest_cpuid_has_spec_ctrl(vcpu)) + return 1; + + /* The STIBP bit doesn't fault even if it's not advertised */ +diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c +index c386d13..3210add 100644 +--- a/arch/x86/kvm/vmx.c ++++ b/arch/x86/kvm/vmx.c +@@ -3017,7 +3017,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) + break; + case MSR_IA32_SPEC_CTRL: + if (!msr_info->host_initiated && +- !guest_cpuid_has_ibrs(vcpu)) ++ !guest_cpuid_has_spec_ctrl(vcpu)) + return 1; + + msr_info->data = to_vmx(vcpu)->spec_ctrl; +@@ -3129,11 +3129,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) + break; + case MSR_IA32_SPEC_CTRL: + if (!msr_info->host_initiated && +- !guest_cpuid_has_ibrs(vcpu)) ++ !guest_cpuid_has_spec_ctrl(vcpu)) + return 1; + + /* The STIBP bit doesn't fault even if it's not advertised */ +- if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP)) ++ if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_RDS)) + return 1; + + vmx->spec_ctrl = data; +-- +2.7.4 + |