[Part2,RFC,v2,20/37] KVM: SVM: define new SEV_FEATURES field in the VMCB Save State Area

Commit Message

Brijesh Singh April 30, 2021, 12:38 p.m. UTC

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, define the VMPL field and update the dump_vmcb().

See APM2 Table 15-34 and B-4 for more details.
---
 arch/x86/include/asm/svm.h | 15 +++++++++++++--
 arch/x86/kvm/svm/svm.c     |  4 ++--
 2 files changed, 15 insertions(+), 4 deletions(-)

Patch

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 ede3cf460894..1b9091d750fc 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3191,8 +3191,8 @@  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",