Using Linux's RDTSC #VC processing logic.
Signed-off-by: Varad Gautam <varad.gautam@xxxxxxxx>
---
lib/x86/amd_sev_vc.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/lib/x86/amd_sev_vc.c b/lib/x86/amd_sev_vc.c
index 91f57e0..45b7ad1 100644
--- a/lib/x86/amd_sev_vc.c
+++ b/lib/x86/amd_sev_vc.c
@@ -153,6 +153,29 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
return ES_OK;
}
+static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ unsigned long exit_code)
+{
+ bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
+ enum es_result ret;
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb) &&
+ (!rdtscp || ghcb_rcx_is_valid(ghcb))))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->rax = ghcb->save.rax;
+ ctxt->regs->rdx = ghcb->save.rdx;
+ if (rdtscp)
+ ctxt->regs->rcx = ghcb->save.rcx;
+
+ return ES_OK;
+}
+
static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
struct ghcb *ghcb,
unsigned long exit_code)
@@ -166,6 +189,10 @@ 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_RDTSC:
+ case SVM_EXIT_RDTSCP:
+ result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
+ break;
default:
/*
* Unexpected #VC exception
--
2.32.0
