From: Tom Lendacky <[email protected]> The guest FPU is automatically restored on VMRUN and saved on VMEXIT by the hardware, so there is no reason to do this in KVM.
Signed-off-by: Tom Lendacky <[email protected]> --- arch/x86/kvm/svm/svm.c | 8 ++++++-- arch/x86/kvm/x86.c | 18 ++++++++++++++---- 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index b35c2de1130c..48699c41b62a 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3682,7 +3682,9 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) svm_set_dr6(svm, DR6_FIXED_1 | DR6_RTM); clgi(); - kvm_load_guest_xsave_state(vcpu); + + if (!sev_es_guest(svm->vcpu.kvm)) + kvm_load_guest_xsave_state(vcpu); if (lapic_in_kernel(vcpu) && vcpu->arch.apic->lapic_timer.timer_advance_ns) @@ -3728,7 +3730,9 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI)) kvm_before_interrupt(&svm->vcpu); - kvm_load_host_xsave_state(vcpu); + if (!sev_es_guest(svm->vcpu.kvm)) + kvm_load_host_xsave_state(vcpu); + stgi(); /* Any pending NMI will happen here */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 76efe70cd635..a53e24c1c5d1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8896,9 +8896,14 @@ 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); + /* + * An encrypted save area means that the guest state can't be + * set by the hypervisor, so skip trying to set it. + */ + if (!vcpu->arch.vmsa_encrypted) + /* 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(); @@ -8911,7 +8916,12 @@ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) { fpregs_lock(); - kvm_save_current_fpu(vcpu->arch.guest_fpu); + /* + * An encrypted save area means that the guest state can't be + * read/saved by the hypervisor, so skip trying to save it. + */ + if (!vcpu->arch.vmsa_encrypted) + kvm_save_current_fpu(vcpu->arch.guest_fpu); copy_kernel_to_fpregs(&vcpu->arch.user_fpu->state); -- 2.28.0
