diff options
Diffstat (limited to 'arch/x86/kvm/vmx/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 7b5abe25e1e5..84f6904cdb6e 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -36,6 +36,7 @@ #include <asm/debugreg.h> #include <asm/desc.h> #include <asm/fpu/api.h> +#include <asm/fpu/xstate.h> #include <asm/idtentry.h> #include <asm/io.h> #include <asm/irq_remapping.h> @@ -761,6 +762,13 @@ void vmx_update_exception_bitmap(struct kvm_vcpu *vcpu) vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, match); } + /* + * Trap #NM if guest xfd contains a non-zero value so guest XFD_ERR + * can be saved timely. + */ + if (vcpu->arch.guest_fpu.fpstate->xfd) + eb |= (1u << NM_VECTOR); + vmcs_write32(EXCEPTION_BITMAP, eb); } @@ -1967,6 +1975,12 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_KERNEL_GS_BASE: vmx_write_guest_kernel_gs_base(vmx, data); break; + case MSR_IA32_XFD: + ret = kvm_set_msr_common(vcpu, msr_info); + /* Update #NM interception according to guest xfd */ + if (!ret) + vmx_update_exception_bitmap(vcpu); + break; #endif case MSR_IA32_SYSENTER_CS: if (is_guest_mode(vcpu)) @@ -4798,6 +4812,17 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) if (is_machine_check(intr_info) || is_nmi(intr_info)) return 1; /* handled by handle_exception_nmi_irqoff() */ + /* + * Queue the exception here instead of in handle_nm_fault_irqoff(). + * This ensures the nested_vmx check is not skipped so vmexit can + * be reflected to L1 (when it intercepts #NM) before reaching this + * point. + */ + if (is_nm_fault(intr_info)) { + kvm_queue_exception(vcpu, NM_VECTOR); + return 1; + } + if (is_invalid_opcode(intr_info)) return handle_ud(vcpu); @@ -6399,6 +6424,26 @@ static void handle_interrupt_nmi_irqoff(struct kvm_vcpu *vcpu, kvm_after_interrupt(vcpu); } +static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu) +{ + /* + * Save xfd_err to guest_fpu before interrupt is enabled, so the + * MSR value is not clobbered by the host activity before the guest + * has chance to consume it. + * + * Do not blindly read xfd_err here, since this exception might + * be caused by L1 interception on a platform which doesn't + * support xfd at all. + * + * Do it conditionally upon guest_fpu::xfd. xfd_err matters + * only when xfd contains a non-zero value. + * + * Queuing exception is done in vmx_handle_exit. See comment there. + */ + if (vcpu->arch.guest_fpu.fpstate->xfd) + rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err); +} + static void handle_exception_nmi_irqoff(struct vcpu_vmx *vmx) { const unsigned long nmi_entry = (unsigned long)asm_exc_nmi_noist; @@ -6407,6 +6452,9 @@ static void handle_exception_nmi_irqoff(struct vcpu_vmx *vmx) /* if exit due to PF check for async PF */ if (is_page_fault(intr_info)) vmx->vcpu.arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags(); + /* if exit due to NM, handle before interrupts are enabled */ + else if (is_nm_fault(intr_info)) + handle_nm_fault_irqoff(&vmx->vcpu); /* Handle machine checks before interrupts are enabled */ else if (is_machine_check(intr_info)) kvm_machine_check(); |