[kvm-unit-tests PATCH v6 09/11] x86: AMD SEV-ES: Handle MSR #VC

[vsntk18@gmail.com]

From: Vasant Karasulli <vkarasulli@suse.de>

Using Linux's MSR #VC processing logic.

Signed-off-by: Varad Gautam <varad.gautam@suse.com>
Signed-off-by: Vasant Karasulli <vkarasulli@suse.de>
Reviewed-by: Marc Orr <marcorr@google.com>
---
 lib/x86/amd_sev_vc.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/lib/x86/amd_sev_vc.c b/lib/x86/amd_sev_vc.c
index 3a5e593c..6238f1ec 100644
--- a/lib/x86/amd_sev_vc.c
+++ b/lib/x86/amd_sev_vc.c
@@ -152,6 +152,31 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
 	return ES_OK;
 }

+static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+	struct ex_regs *regs = ctxt->regs;
+	enum es_result ret;
+	u64 exit_info_1;
+
+	/* Is it a WRMSR? */
+	exit_info_1 = (ctxt->insn.opcode.bytes[1] == 0x30) ? 1 : 0;
+
+	ghcb_set_rcx(ghcb, regs->rcx);
+	if (exit_info_1) {
+		ghcb_set_rax(ghcb, regs->rax);
+		ghcb_set_rdx(ghcb, regs->rdx);
+	}
+
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+
+	if ((ret == ES_OK) && (!exit_info_1)) {
+		regs->rax = ghcb->save.rax;
+		regs->rdx = ghcb->save.rdx;
+	}
+
+	return ret;
+}
+
 static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
 					 struct ghcb *ghcb,
 					 unsigned long exit_code)
@@ -162,6 +187,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
 	case SVM_EXIT_CPUID:
 		result = vc_handle_cpuid(ghcb, ctxt);
 		break;
+	case SVM_EXIT_MSR:
+		result = vc_handle_msr(ghcb, ctxt);
+		break;
 	default:
 		/*
 		 * Unexpected #VC exception
--
2.34.1