KVM: SVM: Define sev_features and VMPL field in the VMSA

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 field through
the SEV_STATUS MSR.

While at it, update 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>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>
Link: https://lore.kernel.org/r/20220307213356.2797205-2-brijesh.singh@amd.com

arch/x86/include/asm/svm.h

@@ -282,7 +282,8 @@ 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;
@@ -347,7 +348,8 @@ 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;

arch/x86/kvm/svm/svm.c

@@ -3117,8 +3117,8 @@ 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",