From: Vasant Karasulli <vkarasulli@xxxxxxx>
Using Linux's MSR #VC processing logic.
Signed-off-by: Varad Gautam <varad.gautam@xxxxxxxx>
Signed-off-by: Vasant Karasulli <vkarasulli@xxxxxxx>
Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
---
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
