KVM: SVM: use .prepare_guest_switch() to handle CPU register save/setup
Currently we save host state like user-visible host MSRs, and do some
initial guest register setup for MSR_TSC_AUX and MSR_AMD64_TSC_RATIO
in svm_vcpu_load(). Defer this until just before we enter the guest by
moving the handling to kvm_x86_ops.prepare_guest_switch() similarly to
how it is done for the VMX implementation.
Additionally, since handling of saving/restoring host user MSRs is the
same both with/without SEV-ES enabled, move that handling to common
code.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-Id: <20210202190126.2185715-4-michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 87167ef..874ea30 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2066,11 +2066,10 @@ void sev_es_create_vcpu(struct vcpu_svm *svm)
sev_enc_bit));
}
-void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu)
+void sev_es_prepare_guest_switch(struct vcpu_svm *svm, unsigned int cpu)
{
struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
struct vmcb_save_area *hostsa;
- unsigned int i;
/*
* As an SEV-ES guest, hardware will restore the host state on VMEXIT,
@@ -2079,13 +2078,6 @@ void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu)
*/
vmsave(__sme_page_pa(sd->save_area));
- /*
- * Certain MSRs are restored on VMEXIT, only save ones that aren't
- * restored.
- */
- for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
- rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
-
/* XCR0 is restored on VMEXIT, save the current host value */
hostsa = (struct vmcb_save_area *)(page_address(sd->save_area) + 0x400);
hostsa->xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
@@ -2097,18 +2089,6 @@ void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu)
hostsa->xss = host_xss;
}
-void sev_es_vcpu_put(struct vcpu_svm *svm)
-{
- unsigned int i;
-
- /*
- * Certain MSRs are restored on VMEXIT and were saved with vmsave in
- * sev_es_vcpu_load() above. Only restore ones that weren't.
- */
- for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
- wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
-}
-
void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
{
struct vcpu_svm *svm = to_svm(vcpu);