From f676aa34b4027d1a7a4bbcc58b81b20c68c7ce0c Mon Sep 17 00:00:00 2001 From: Wei Wang <wei.w.wang@intel.com> Date: Tue, 7 Nov 2017 16:47:53 +0800 Subject: [PATCH] x86/kvm: add MSR_IA32_SPEC_CTRL and MSR_IA32_PRED_CMD to kvm CVE-2017-5715 (Spectre v2 Intel) Add field to access guest MSR_IA332_SPEC_CTRL and MSR_IA32_PRED_CMD state. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Andy Whitcroft <apw@canonical.com> (backported from commit f93ba2a9b5ab2c275e9adc10876cc0425a33eec0) Signed-off-by: Andy Whitcroft <apw@canonical.com> Acked-by: Colin Ian King <colin.king@canonical.com> Acked-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com> --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/vmx.c | 10 ++++++++++ arch/x86/kvm/x86.c | 2 +- 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 9e279405d198..71d8c7cc569d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -557,6 +557,8 @@ struct kvm_vcpu_arch { u64 mcg_ctl; u64 *mce_banks; + u64 spec_ctrl; + /* Cache MMIO info */ u64 mmio_gva; unsigned access; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6e9ddacc97e0..f1f0a2dc6327 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -49,6 +49,7 @@ #include <asm/apic.h> #include <asm/irq_remapping.h> #include <asm/nospec-branch.h> +#include <asm/microcode.h> #include "trace.h" #include "pmu.h" @@ -2804,6 +2805,9 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_TSC: msr_info->data = guest_read_tsc(vcpu); break; + case MSR_IA32_SPEC_CTRL: + msr_info->data = vcpu->arch.spec_ctrl; + break; case MSR_IA32_SYSENTER_CS: msr_info->data = vmcs_read32(GUEST_SYSENTER_CS); break; @@ -2903,6 +2907,9 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_TSC: kvm_write_tsc(vcpu, msr_info); break; + case MSR_IA32_SPEC_CTRL: + vcpu->arch.spec_ctrl = msr_info->data; + break; case MSR_IA32_CR_PAT: if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) { if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data)) @@ -5681,6 +5688,7 @@ static int handle_rdmsr(struct kvm_vcpu *vcpu) msr_info.index = ecx; msr_info.host_initiated = false; + if (vmx_get_msr(vcpu, &msr_info)) { trace_kvm_msr_read_ex(ecx); kvm_inject_gp(vcpu, 0); @@ -6274,6 +6282,8 @@ static __init int hardware_setup(void) vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_CS, false); vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_ESP, false); vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP, false); + vmx_disable_intercept_for_msr(MSR_IA32_SPEC_CTRL, false); + vmx_disable_intercept_for_msr(MSR_IA32_PRED_CMD, false); memcpy(vmx_msr_bitmap_legacy_x2apic, vmx_msr_bitmap_legacy, PAGE_SIZE); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d2db7598a9de..201469f0bbb5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -960,7 +960,7 @@ static u32 msrs_to_save[] = { MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR, #endif MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA, - MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX, + MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX, MSR_IA32_SPEC_CTRL, }; static unsigned num_msrs_to_save; -- 2.30.9