From: Tom Lendacky <thomas.lendacky@xxxxxxx>
Implement a handler for #VC exceptions caused by VMMCALL instructions.
This patch is only a starting point, VMMCALL emulation under SEV-ES
needs further hypervisor-specific changes to provide additional state.
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
[ jroedel@xxxxxxx: Adapt to #VC handling infrastructure ]
Co-developed-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/kernel/sev-es.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 0d0b6e15f7d9..db8e33280f7a 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -889,6 +889,26 @@ static enum es_result vc_handle_mwait(struct ghcb *ghcb,
return ES_OK;
}
+static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ enum es_result ret;
+
+ ghcb_set_rax(ghcb, ctxt->regs->ax);
+ ghcb_set_cpl(ghcb, user_mode(ctxt->regs) ? 3 : 0);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!ghcb_rax_is_valid(ghcb))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+
+ return ES_OK;
+}
+
static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
struct ghcb *ghcb,
unsigned long exit_code)
@@ -922,6 +942,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
case SVM_EXIT_MSR:
result = vc_handle_msr(ghcb, ctxt);
break;
+ case SVM_EXIT_VMMCALL:
+ result = vc_handle_vmmcall(ghcb, ctxt);
+ break;
case SVM_EXIT_WBINVD:
result = vc_handle_wbinvd(ghcb, ctxt);
break;
--
2.28.0
