diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0032-KVM-x86-Remove-indirect-MSR-op-calls-from-SPEC_CTRL.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0032-KVM-x86-Remove-indirect-MSR-op-calls-from-SPEC_CTRL.patch | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0032-KVM-x86-Remove-indirect-MSR-op-calls-from-SPEC_CTRL.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0032-KVM-x86-Remove-indirect-MSR-op-calls-from-SPEC_CTRL.patch new file mode 100644 index 00000000..4f0b4222 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0032-KVM-x86-Remove-indirect-MSR-op-calls-from-SPEC_CTRL.patch @@ -0,0 +1,105 @@ +From 0ebeae5f6b25b48c0559950e2b7c2f0a1ffd641c Mon Sep 17 00:00:00 2001 +From: Paolo Bonzini <pbonzini@redhat.com> +Date: Thu, 22 Feb 2018 16:43:17 +0100 +Subject: [PATCH 32/33] KVM/x86: Remove indirect MSR op calls from SPEC_CTRL +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +commit ecb586bd29c99fb4de599dec388658e74388daad upstream. + +Having a paravirt indirect call in the IBRS restore path is not a +good idea, since we are trying to protect from speculative execution +of bogus indirect branch targets. It is also slower, so use +native_wrmsrl() on the vmentry path too. + +Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> +Reviewed-by: Jim Mattson <jmattson@google.com> +Cc: David Woodhouse <dwmw@amazon.co.uk> +Cc: KarimAllah Ahmed <karahmed@amazon.de> +Cc: Linus Torvalds <torvalds@linux-foundation.org> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: Radim Krčmář <rkrcmar@redhat.com> +Cc: Thomas Gleixner <tglx@linutronix.de> +Cc: kvm@vger.kernel.org +Cc: stable@vger.kernel.org +Fixes: d28b387fb74da95d69d2615732f50cceb38e9a4d +Link: http://lkml.kernel.org/r/20180222154318.20361-2-pbonzini@redhat.com +Signed-off-by: Ingo Molnar <mingo@kernel.org> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kvm/svm.c | 7 ++++--- + arch/x86/kvm/vmx.c | 7 ++++--- + 2 files changed, 8 insertions(+), 6 deletions(-) + +diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c +index 4a36977..8d33396 100644 +--- a/arch/x86/kvm/svm.c ++++ b/arch/x86/kvm/svm.c +@@ -44,6 +44,7 @@ + #include <asm/debugreg.h> + #include <asm/kvm_para.h> + #include <asm/irq_remapping.h> ++#include <asm/microcode.h> + #include <asm/nospec-branch.h> + + #include <asm/virtext.h> +@@ -4907,7 +4908,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu) + * being speculatively taken. + */ + if (svm->spec_ctrl) +- wrmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl); ++ native_wrmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl); + + asm volatile ( + "push %%" _ASM_BP "; \n\t" +@@ -5017,10 +5018,10 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu) + * save it. + */ + if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL)) +- rdmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl); ++ svm->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL); + + if (svm->spec_ctrl) +- wrmsrl(MSR_IA32_SPEC_CTRL, 0); ++ native_wrmsrl(MSR_IA32_SPEC_CTRL, 0); + + /* Eliminate branch target predictions from guest mode */ + vmexit_fill_RSB(); +diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c +index f6c0568..aa2684a 100644 +--- a/arch/x86/kvm/vmx.c ++++ b/arch/x86/kvm/vmx.c +@@ -49,6 +49,7 @@ + #include <asm/kexec.h> + #include <asm/apic.h> + #include <asm/irq_remapping.h> ++#include <asm/microcode.h> + #include <asm/nospec-branch.h> + + #include "trace.h" +@@ -8888,7 +8889,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) + * being speculatively taken. + */ + if (vmx->spec_ctrl) +- wrmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl); ++ native_wrmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl); + + vmx->__launched = vmx->loaded_vmcs->launched; + asm( +@@ -9024,10 +9025,10 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) + * save it. + */ + if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL)) +- rdmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl); ++ vmx->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL); + + if (vmx->spec_ctrl) +- wrmsrl(MSR_IA32_SPEC_CTRL, 0); ++ native_wrmsrl(MSR_IA32_SPEC_CTRL, 0); + + /* Eliminate branch target predictions from guest mode */ + vmexit_fill_RSB(); +-- +2.7.4 + |