diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 56 |
3 files changed, 56 insertions, 10 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 2b6f168436c8..39707e72b062 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1477,6 +1477,8 @@ void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector); int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index, int reason, bool has_error_code, u32 error_code); +void kvm_free_guest_fpu(struct kvm_vcpu *vcpu); + void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned long cr0); void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned long cr4); int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 6064a6035dbb..f1c32cdc9d49 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1317,6 +1317,14 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) vmsa_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); if (!vmsa_page) goto error_free_vmcb_page; + + /* + * SEV-ES guests maintain an encrypted version of their FPU + * state which is restored and saved on VMRUN and VMEXIT. + * Free the fpu structure to prevent KVM from attempting to + * access the FPU state. + */ + kvm_free_guest_fpu(vcpu); } err = avic_init_vcpu(svm); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ba8e6a9b1a77..eea0e9fed62a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4503,6 +4503,9 @@ static void load_xsave(struct kvm_vcpu *vcpu, u8 *src) static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu, struct kvm_xsave *guest_xsave) { + if (!vcpu->arch.guest_fpu) + return; + if (boot_cpu_has(X86_FEATURE_XSAVE)) { memset(guest_xsave, 0, sizeof(struct kvm_xsave)); fill_xsave((u8 *) guest_xsave->region, vcpu); @@ -4520,9 +4523,14 @@ static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu, static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu, struct kvm_xsave *guest_xsave) { - u64 xstate_bv = - *(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)]; - u32 mxcsr = *(u32 *)&guest_xsave->region[XSAVE_MXCSR_OFFSET / sizeof(u32)]; + u64 xstate_bv; + u32 mxcsr; + + if (!vcpu->arch.guest_fpu) + return 0; + + xstate_bv = *(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)]; + mxcsr = *(u32 *)&guest_xsave->region[XSAVE_MXCSR_OFFSET / sizeof(u32)]; if (boot_cpu_has(X86_FEATURE_XSAVE)) { /* @@ -9245,9 +9253,14 @@ static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) kvm_save_current_fpu(vcpu->arch.user_fpu); - /* PKRU is separately restored in kvm_x86_ops.run. */ - __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu->state, - ~XFEATURE_MASK_PKRU); + /* + * Guests with protected state can't have it set by the hypervisor, + * so skip trying to set it. + */ + if (vcpu->arch.guest_fpu) + /* PKRU is separately restored in kvm_x86_ops.run. */ + __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu->state, + ~XFEATURE_MASK_PKRU); fpregs_mark_activate(); fpregs_unlock(); @@ -9260,7 +9273,12 @@ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) { fpregs_lock(); - kvm_save_current_fpu(vcpu->arch.guest_fpu); + /* + * Guests with protected state can't have it read by the hypervisor, + * so skip trying to save it. + */ + if (vcpu->arch.guest_fpu) + kvm_save_current_fpu(vcpu->arch.guest_fpu); copy_kernel_to_fpregs(&vcpu->arch.user_fpu->state); @@ -9770,6 +9788,9 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) { struct fxregs_state *fxsave; + if (!vcpu->arch.guest_fpu) + return 0; + vcpu_load(vcpu); fxsave = &vcpu->arch.guest_fpu->state.fxsave; @@ -9790,6 +9811,9 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) { struct fxregs_state *fxsave; + if (!vcpu->arch.guest_fpu) + return 0; + vcpu_load(vcpu); fxsave = &vcpu->arch.guest_fpu->state.fxsave; @@ -9848,6 +9872,9 @@ static int sync_regs(struct kvm_vcpu *vcpu) static void fx_init(struct kvm_vcpu *vcpu) { + if (!vcpu->arch.guest_fpu) + return; + fpstate_init(&vcpu->arch.guest_fpu->state); if (boot_cpu_has(X86_FEATURE_XSAVES)) vcpu->arch.guest_fpu->state.xsave.header.xcomp_bv = @@ -9861,6 +9888,15 @@ static void fx_init(struct kvm_vcpu *vcpu) vcpu->arch.cr0 |= X86_CR0_ET; } +void kvm_free_guest_fpu(struct kvm_vcpu *vcpu) +{ + if (vcpu->arch.guest_fpu) { + kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu); + vcpu->arch.guest_fpu = NULL; + } +} +EXPORT_SYMBOL_GPL(kvm_free_guest_fpu); + int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) { if (kvm_check_tsc_unstable() && atomic_read(&kvm->online_vcpus) != 0) @@ -9956,7 +9992,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) return 0; free_guest_fpu: - kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu); + kvm_free_guest_fpu(vcpu); free_user_fpu: kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu); free_emulate_ctxt: @@ -10010,7 +10046,7 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) kmem_cache_free(x86_emulator_cache, vcpu->arch.emulate_ctxt); free_cpumask_var(vcpu->arch.wbinvd_dirty_mask); kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu); - kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu); + kvm_free_guest_fpu(vcpu); kvm_hv_vcpu_uninit(vcpu); kvm_pmu_destroy(vcpu); @@ -10058,7 +10094,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) kvm_async_pf_hash_reset(vcpu); vcpu->arch.apf.halted = false; - if (kvm_mpx_supported()) { + if (vcpu->arch.guest_fpu && kvm_mpx_supported()) { void *mpx_state_buffer; /* |