>From d5ad36ae7d7aef4c6b97cf624bc38b3b0ec37515 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 13 Jun 2024 10:28:29 -0700 Subject: [PATCH 14/28] KVM: VMX: Pass XFD_ERR as pseudo-payload when injecting #NM Pass XFD_ERR via KVM's exception payload mechanism when injecting an #NM after interception so that XFD_ERR can be propagated to FRED's event_data field without needing a dedicated field (which would need to be migrated). For non-FRED vCPUs, this is a glorified NOP as kvm_deliver_exception_payload() will simply do nothing (which is desirable and correct). Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d916199f1e60..f0643aa1f4ef 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5316,6 +5316,12 @@ bool vmx_guest_inject_ac(struct kvm_vcpu *vcpu) (kvm_get_rflags(vcpu) & X86_EFLAGS_AC); } +static bool is_xfd_nm_fault(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.guest_fpu.fpstate->xfd && + !kvm_is_cr0_bit_set(vcpu, X86_CR0_TS); +} + static int handle_exception_nmi(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -5342,7 +5348,8 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) * point. */ if (is_nm_fault(intr_info)) { - kvm_queue_exception(vcpu, NM_VECTOR); + kvm_queue_exception_p(vcpu, NM_VECTOR, + is_xfd_nm_fault(vcpu) ? vcpu->arch.guest_fpu.xfd_err : 0); return 1; } @@ -7075,14 +7082,13 @@ static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu) * * Update the guest's XFD_ERR if and only if XFD is enabled, as the #NM * interception may have been caused by L1 interception. Per the SDM, - * XFD_ERR is not modified if CR0.TS=1. + * XFD_ERR is not modified for non-XFD #NM, i.e. if CR0.TS=1. * * Note, XFD_ERR is updated _before_ the #NM interception check, i.e. * unlike CR2 and DR6, the value is not a payload that is attached to * the #NM exception. */ - if (vcpu->arch.guest_fpu.fpstate->xfd && - !kvm_is_cr0_bit_set(vcpu, X86_CR0_TS)) + if (is_xfd_nm_fault(vcpu)) rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err); } -- 2.45.2.627.g7a2c4fd464-goog