[PATCH v12 18/29] KVM: SEV: Use a VMSA physical address variable for populating VMCB

Michael Roth
2024-03-29T23:02:40Z

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>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
arch/x86/kvm/svm/sev.c | 3 +--
arch/x86/kvm/svm/svm.c | 9 ++++++++-
arch/x86/kvm/svm/svm.h | 1 +
3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index a0a88471f9ab..ce1c727bad23 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3780,8 +3780,7 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
* the VMSA will be NULL if this vCPU is the destination for intrahost
* migration, and will be copied later.
*/
- if (svm->sev_es.vmsa)
- 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 648a05ca53fc..e036a8927717 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1451,9 +1451,16 @@ 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 c0675ff2d8a2..8cce3315b46c 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -199,6 +199,7 @@ struct vcpu_sev_es_state {
struct ghcb *ghcb;
u8 valid_bitmap[16];
struct kvm_host_map ghcb_map;
+ hpa_t vmsa_pa;
bool received_first_sipi;
unsigned int ap_reset_hold_type;

--
2.25.1