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@amd.com>
[ jroedel@suse.de: Adapt to #VC handling infrastructure ]
Co-developed-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-58-joro@8bytes.org

diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 236cfc1..b9976e7 100644 (file)
--- 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;