From: Tom Lendacky <[email protected]>

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

Signed-off-by: Tom Lendacky <[email protected]>
[ [email protected]: Adapt to #VC handling infrastructure ]
Co-developed-by: Joerg Roedel <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
---
 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 2d19a5e8388d..826a9f704d5b 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;
-- 
2.27.0

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