[PATCH Part2 RFC v3 36/37] KVM: SVM: Use a VMSA physical address variable for populating VMCB

Brijesh Singh
2021-06-02T14:17:01Z

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 5718e2e07788..047f4dbde99b 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3409,10 +3409,9 @@ 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->vmsa);
+ svm->vmcb->control.vmsa_pa = svm->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 32e35d396508..74bc635c9608 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1379,9 +1379,16 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu)
svm->vmcb01.ptr = page_address(vmcb01_page);
svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT);

- if (vmsa_page)
+ if (vmsa_page) {
svm->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->vmsa_pa = __pa(svm->vmsa);
+ }
+
svm->guest_state_loaded = false;

svm_switch_vmcb(svm, &svm->vmcb01);
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index d4efcda3070d..52fd3cf30ad9 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -176,6 +176,7 @@ struct vcpu_svm {

/* SEV-ES support */
struct sev_es_save_area *vmsa;
+ hpa_t vmsa_pa;
struct ghcb *ghcb;
struct kvm_host_map ghcb_map;
bool received_first_sipi;
--
2.17.1