This produces a good error message instead of:

KVM: unknown exit reason 24
EAX=00000000 EBX=00000000 ECX=00000000 EDX=00a00f11
ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
EIP=0000b004 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=1
ES =0000 00000000 0000ffff 00009300
CS =f000 00800000 0000ffff 00009b00
SS =0000 00000000 0000ffff 00009300
DS =0000 00000000 0000ffff 00009300
FS =0000 00000000 0000ffff 00009300
GS =0000 00000000 0000ffff 00009300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 0000ffff
IDT=     00000000 0000ffff
CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Reported-by: Jin Liu <jinl@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 qapi/run-state.json      | 23 +++++++++++++++++++++--
 accel/kvm/kvm-all.c      |  1 +
 system/runstate.c        |  4 ++++
 target/i386/cpu-system.c | 22 ++++++++++++++++++++++
 4 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/qapi/run-state.json b/qapi/run-state.json
index a6bc94a44bb..a5771ad4681 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -504,10 +504,12 @@
 #
 # @tdx: tdx guest panic information type (Since: 10.1)
 #
+# @sev: AMD SEV-ES guest termination information type (Since: 11.0)
+#
 # Since: 2.9
 ##
 { 'enum': 'GuestPanicInformationType',
-  'data': [ 'hyper-v', 's390', 'tdx' ] }
+  'data': [ 'hyper-v', 's390', 'tdx', 'sev' ] }
 
 ##
 # @GuestPanicInformation:
@@ -523,7 +525,8 @@
  'discriminator': 'type',
  'data': {'hyper-v': 'GuestPanicInformationHyperV',
           's390': 'GuestPanicInformationS390',
-          'tdx' : 'GuestPanicInformationTdx'}}
+          'tdx': 'GuestPanicInformationTdx',
+          'sev': 'GuestPanicInformationSev' }}
 
 ##
 # @GuestPanicInformationHyperV:
@@ -625,6 +628,22 @@
           'message': 'str',
           '*gpa': 'uint64'}}
 
+##
+# @GuestPanicInformationSev:
+#
+# Information for AMD SEV-specific termination request (GHCB MSR
+# contents)
+#
+# @set: The reason code set provided by the guest
+#
+# @code: The reason code provided by the guest
+#
+# Since: 11.0
+##
+{'struct': 'GuestPanicInformationSev',
+ 'data': {'set': 'uint32',
+          'code': 'uint32'}}
+
 ##
 # @MEMORY_FAILURE:
 #
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 8301a512e7f..0d8b0c43470 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -3300,6 +3300,7 @@ int kvm_cpu_exec(CPUState *cpu)
                 qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
                 ret = EXCP_INTERRUPT;
                 break;
+            case KVM_SYSTEM_EVENT_SEV_TERM:
             case KVM_SYSTEM_EVENT_CRASH:
                 kvm_cpu_synchronize_state(cpu);
                 bql_lock();
diff --git a/system/runstate.c b/system/runstate.c
index ed2db564806..d091a2bdddb 100644
--- a/system/runstate.c
+++ b/system/runstate.c
@@ -669,6 +669,10 @@ void qemu_system_guest_panicked(GuestPanicInformation *info)
                               "can be found at gpa page: 0x%" PRIx64 "\n",
                               info->u.tdx.gpa);
             }
+        } else if (info->type == GUEST_PANIC_INFORMATION_TYPE_SEV) {
+            qemu_log_mask(LOG_GUEST_ERROR, "SEV termination (reason set: %d code: %d)",
+                          info->u.sev.set,
+                          info->u.sev.code);
         }
 
         qapi_free_GuestPanicInformation(info);
diff --git a/target/i386/cpu-system.c b/target/i386/cpu-system.c
index b1494aa6740..c8bbf0cbafd 100644
--- a/target/i386/cpu-system.c
+++ b/target/i386/cpu-system.c
@@ -18,6 +18,8 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "system/kvm.h"
 #include "cpu.h"
 #include "qapi/error.h"
 #include "qapi/qapi-visit-run-state.h"
@@ -272,6 +274,26 @@ GuestPanicInformation *x86_cpu_get_crash_info(CPUState *cs)
     CPUX86State *env = &cpu->env;
     GuestPanicInformation *panic_info = NULL;
 
+#ifdef CONFIG_KVM
+    if (kvm_enabled()) {
+        struct kvm_run *run = cs->kvm_run;
+
+        if (run->exit_reason == KVM_EXIT_SYSTEM_EVENT &&
+            run->system_event.type == KVM_SYSTEM_EVENT_SEV_TERM) {
+            panic_info = g_new0(GuestPanicInformation, 1);
+
+            panic_info->type = GUEST_PANIC_INFORMATION_TYPE_SEV;
+            /* There should always be one data item, otherwise use zeroes.  */
+            if (run->system_event.ndata > 0) {
+                panic_info->u.sev.set = (run->system_event.data[0] >> 12) & 0xf;
+                panic_info->u.sev.code = (run->system_event.data[0] >> 16) & 0xff;
+            } else {
+                warn_report("Hypervisor did not provide any data for SEV-ES termination");
+            }
+        }
+    } else
+#endif
+
     if (hyperv_feat_enabled(cpu, HYPERV_FEAT_CRASH)) {
         panic_info = g_new0(GuestPanicInformation, 1);
 
-- 
2.52.0