[PATCH Part2 v6 43/49] KVM: SVM: Use a VMSA physical address variable for populating VMCB

Ashish Kalra
2022-06-20T23:14:12Z

From: Tom Lendacky <thomas.lendacky@amd.com>

In preparation to support SEV-SNP AP Creation, use a variable that holds
the VMSA physical address rather than converting the virtual address.
This will allow SEV-SNP AP Creation to set the new physical address that
will be used should the vCPU reset path be taken.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/kvm/svm/sev.c | 5 ++---
arch/x86/kvm/svm/svm.c | 9 ++++++++-
arch/x86/kvm/svm/svm.h | 1 +
3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 089af21a4efe..d5584551f3dd 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3980,10 +3980,9 @@ void sev_es_init_vmcb(struct vcpu_svm *svm)

/*
* An SEV-ES guest requires a VMSA area that is a separate from the
- * VMCB page. Do not include the encryption mask on the VMSA physical
- * address since hardware will access it using the guest key.
+ * VMCB page.
*/
- svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
+ svm->vmcb->control.vmsa_pa = svm->sev_es.vmsa_pa;

/* Can't intercept CR register access, HV can't modify CR registers */
svm_clr_intercept(svm, INTERCEPT_CR0_READ);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 7742bc986afc..f7155abe7567 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1296,9 +1296,16 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu)
svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT);
svm_switch_vmcb(svm, &svm->vmcb01);

- if (vmsa_page)
+ if (vmsa_page) {
svm->sev_es.vmsa = page_address(vmsa_page);

+ /*
+ * Do not include the encryption mask on the VMSA physical
+ * address since hardware will access it using the guest key.
+ */
+ svm->sev_es.vmsa_pa = __pa(svm->sev_es.vmsa);
+ }
+
svm->guest_state_loaded = false;

return 0;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 3be24da1a743..46790bab07a8 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -197,6 +197,7 @@ struct svm_nested_state {
struct vcpu_sev_es_state {
/* SEV-ES support */
struct sev_es_save_area *vmsa;
+ hpa_t vmsa_pa;
bool ghcb_in_use;
bool received_first_sipi;
unsigned int ap_reset_hold_type;
--
2.25.1