[PATCH v6 60/76] x86/sev-es: Handle MONITOR/MONITORX Events

[Joerg Roedel]

From: Tom Lendacky <thomas.lendacky@xxxxxxx>

Implement a handler for #VC exceptions caused by MONITOR and MONITORX
instructions.

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>
Link: https://lore.kernel.org/r/20200724160336.5435-60-joro@xxxxxxxxxx
---
 arch/x86/kernel/sev-es.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 4e1989c58df8..c7324cd0a4d6 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -872,6 +872,16 @@ static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt
 	return ES_OK;
 }
 
+static enum es_result vc_handle_monitor(struct ghcb *ghcb,
+					struct es_em_ctxt *ctxt)
+{
+	/*
+	 * Treat it as a NOP and do not leak a physical address to the
+	 * hypervisor
+	 */
+	return ES_OK;
+}
+
 static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
 					 struct ghcb *ghcb,
 					 unsigned long exit_code)
@@ -908,6 +918,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
 	case SVM_EXIT_WBINVD:
 		result = vc_handle_wbinvd(ghcb, ctxt);
 		break;
+	case SVM_EXIT_MONITOR:
+		result = vc_handle_monitor(ghcb, ctxt);
+		break;
 	case SVM_EXIT_NPF:
 		result = vc_handle_mmio(ghcb, ctxt);
 		break;
-- 
2.28.0