[PATCH v6 29/60] i386/tdx: Handle KVM_SYSTEM_EVENT_TDX_FATAL

[Xiaoyao Li <xiaoyao.li@intel.com>]

TD guest can use TDG.VP.VMCALL<REPORT_FATAL_ERROR> to request
termination. KVM translates such request into KVM_EXIT_SYSTEM_EVENT with
type of KVM_SYSTEM_EVENT_TDX_FATAL.

Add hanlder for such exit. Parse and print the error message, and
terminate the TD guest in the handler.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
Changes in v6:
 - replace the patch " i386/tdx: Handle TDG.VP.VMCALL<REPORT_FATAL_ERROR>"
   in v5;
---
 target/i386/kvm/kvm.c      | 10 ++++++++++
 target/i386/kvm/tdx-stub.c |  5 +++++
 target/i386/kvm/tdx.c      | 24 ++++++++++++++++++++++++
 target/i386/kvm/tdx.h      |  2 ++
 4 files changed, 41 insertions(+)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 4fafc003e9a7..dea0f83370d5 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -6116,6 +6116,16 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
     case KVM_EXIT_HYPERCALL:
         ret = kvm_handle_hypercall(run);
         break;
+    case KVM_EXIT_SYSTEM_EVENT:
+        switch (run->system_event.type) {
+        case KVM_SYSTEM_EVENT_TDX_FATAL:
+            ret = tdx_handle_report_fatal_error(cpu, run);
+            break;
+        default:
+            ret = -1;
+            break;
+        }
+        break;
     default:
         fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
         ret = -1;
diff --git a/target/i386/kvm/tdx-stub.c b/target/i386/kvm/tdx-stub.c
index a064d583d393..b5cb6d56c46a 100644
--- a/target/i386/kvm/tdx-stub.c
+++ b/target/i386/kvm/tdx-stub.c
@@ -11,3 +11,8 @@ int tdx_parse_tdvf(void *flash_ptr, int size)
 {
     return -EINVAL;
 }
+
+int tdx_handle_report_fatal_error(X86CPU *cpu, struct kvm_run *run)
+{
+    return -EINVAL;
+}
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index b34707e93f4d..3f44dfbf6585 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -574,6 +574,30 @@ int tdx_parse_tdvf(void *flash_ptr, int size)
     return tdvf_parse_metadata(&tdx_guest->tdvf, flash_ptr, size);
 }
 
+int tdx_handle_report_fatal_error(X86CPU *cpu, struct kvm_run *run)
+{
+    uint64_t error_code = run->system_event.data[0];
+    char *message = NULL;
+
+    if (error_code & 0xffff) {
+        error_report("TDX: REPORT_FATAL_ERROR: invalid error code: 0x%lx",
+                     error_code);
+        return -1;
+    }
+
+    /* It has optional message */
+    if (run->system_event.data[2]) {
+#define TDX_FATAL_MESSAGE_MAX        64
+        message = g_malloc0(TDX_FATAL_MESSAGE_MAX + 1);
+
+        memcpy(message, &run->system_event.data[2], TDX_FATAL_MESSAGE_MAX);
+        message[TDX_FATAL_MESSAGE_MAX] = '\0';
+    }
+
+    error_report("TD guest reports fatal error. %s", message ? : "");
+    return -1;
+}
+
 static bool tdx_guest_get_sept_ve_disable(Object *obj, Error **errp)
 {
     TdxGuest *tdx = TDX_GUEST(obj);
diff --git a/target/i386/kvm/tdx.h b/target/i386/kvm/tdx.h
index c669e0d0daca..7222a5d31359 100644
--- a/target/i386/kvm/tdx.h
+++ b/target/i386/kvm/tdx.h
@@ -6,6 +6,7 @@
 #endif
 
 #include "confidential-guest.h"
+#include "cpu.h"
 #include "hw/i386/tdvf.h"
 
 #define TYPE_TDX_GUEST "tdx-guest"
@@ -57,5 +58,6 @@ bool is_tdx_vm(void);
 int tdx_pre_create_vcpu(CPUState *cpu, Error **errp);
 void tdx_set_tdvf_region(MemoryRegion *tdvf_mr);
 int tdx_parse_tdvf(void *flash_ptr, int size);
+int tdx_handle_report_fatal_error(X86CPU *cpu, struct kvm_run *run);
 
 #endif /* QEMU_I386_TDX_H */
-- 
2.34.1