[tip: x86/seves] x86/sev-es: Handle MONITOR/MONITORX Events

[tip-bot2 for Tom Lendacky]

The following commit has been merged into the x86/seves branch of tip:

Commit-ID:     0c2fd2ef64ef1a91d81c2f61309735ac438b68a4
Gitweb:        https://git.kernel.org/tip/0c2fd2ef64ef1a91d81c2f61309735ac438b68a4
Author:        Tom Lendacky <thomas.lendacky@xxxxxxx>
AuthorDate:    Mon, 07 Sep 2020 15:15:58 +02:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Wed, 09 Sep 2020 11:33:20 +02:00

x86/sev-es: Handle MONITOR/MONITORX Events

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>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lkml.kernel.org/r/20200907131613.12703-58-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 236cfc1..b9976e7 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;