From ed02b213098a90c2a415a0da18f05841f8cf0a81 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Thu, 10 Dec 2020 11:10:01 -0600 Subject: KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest The guest FPU state is automatically restored on VMRUN and saved on VMEXIT by the hardware, so there is no reason to do this in KVM. Eliminate the allocation of the guest_fpu save area and key off that to skip operations related to the guest FPU state. Signed-off-by: Tom Lendacky Message-Id: <173e429b4d0d962c6a443c4553ffdaf31b7665a4.1607620209.git.thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/svm.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/x86/kvm/svm') 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); -- cgit v1.2.3