[PATCH Part1 RFC v4 16/36] KVM: SVM: define new SEV_FEATURES field in the VMCB Save State Area

Brijesh Singh
2021-07-07T18:17:21Z

The hypervisor uses the SEV_FEATURES field (offset 3B0h) in the Save State
Area to control the SEV-SNP guest features such as SNPActive, vTOM,
ReflectVC etc. An SEV-SNP guest can read the SEV_FEATURES fields through
the SEV_STATUS MSR.

While at it, update the dump_vmcb() to log the VMPL level.

See APM2 Table 15-34 and B-4 for more details.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/include/asm/svm.h | 15 +++++++++++++--
arch/x86/kvm/svm/svm.c | 4 ++--
2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 772e60efe243..ff614cdcf628 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -212,6 +212,15 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
#define SVM_NESTED_CTL_SEV_ENABLE BIT(1)
#define SVM_NESTED_CTL_SEV_ES_ENABLE BIT(2)

+#define SVM_SEV_FEATURES_SNP_ACTIVE BIT(0)
+#define SVM_SEV_FEATURES_VTOM BIT(1)
+#define SVM_SEV_FEATURES_REFLECT_VC BIT(2)
+#define SVM_SEV_FEATURES_RESTRICTED_INJECTION BIT(3)
+#define SVM_SEV_FEATURES_ALTERNATE_INJECTION BIT(4)
+#define SVM_SEV_FEATURES_DEBUG_SWAP BIT(5)
+#define SVM_SEV_FEATURES_PREVENT_HOST_IBS BIT(6)
+#define SVM_SEV_FEATURES_BTB_ISOLATION BIT(7)
+
struct vmcb_seg {
u16 selector;
u16 attrib;
@@ -230,7 +239,8 @@ struct vmcb_save_area {
struct vmcb_seg ldtr;
struct vmcb_seg idtr;
struct vmcb_seg tr;
- u8 reserved_1[43];
+ u8 reserved_1[42];
+ u8 vmpl;
u8 cpl;
u8 reserved_2[4];
u64 efer;
@@ -295,7 +305,8 @@ struct vmcb_save_area {
u64 sw_exit_info_1;
u64 sw_exit_info_2;
u64 sw_scratch;
- u8 reserved_11[56];
+ u64 sev_features;
+ u8 reserved_11[48];
u64 xcr0;
u8 valid_bitmap[16];
u64 x87_state_gpa;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index e088086f3de6..293c9e03da5a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3184,8 +3184,8 @@ static void dump_vmcb(struct kvm_vcpu *vcpu)
"tr:",
save01->tr.selector, save01->tr.attrib,
save01->tr.limit, save01->tr.base);
- pr_err("cpl: %d efer: %016llx\n",
- save->cpl, save->efer);
+ pr_err("vmpl: %d cpl: %d efer: %016llx\n",
+ save->vmpl, save->cpl, save->efer);
pr_err("%-15s %016llx %-13s %016llx\n",
"cr0:", save->cr0, "cr2:", save->cr2);
pr_err("%-15s %016llx %-13s %016llx\n",
--
2.17.1