[PATCH v3 57/70] i386/tdx: Wire TDX_REPORT_FATAL_ERROR with GuestPanic facility

Xiaoyao Li
2023-11-15T07:23:00Z

Integrate TDX's TDX_REPORT_FATAL_ERROR into QEMU GuestPanic facility

Originated-from: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
Changes from v2:
- Add docmentation of new type and struct (Daniel)
- refine the error message handling (Daniel)
---
qapi/run-state.json | 27 ++++++++++++++++++++--
system/runstate.c | 54 +++++++++++++++++++++++++++++++++++++++++++
target/i386/kvm/tdx.c | 24 +++++++++++++++++--
3 files changed, 101 insertions(+), 4 deletions(-)

diff --git a/qapi/run-state.json b/qapi/run-state.json
index f216ba54ec4c..e18f62eaef77 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -496,10 +496,12 @@
#
# @s390: s390 guest panic information type (Since: 2.12)
#
+# @tdx: tdx guest panic information type (Since: 8.2)
+#
# Since: 2.9
##
{ 'enum': 'GuestPanicInformationType',
- 'data': [ 'hyper-v', 's390' ] }
+ 'data': [ 'hyper-v', 's390', 'tdx' ] }

##
# @GuestPanicInformation:
@@ -514,7 +516,8 @@
'base': {'type': 'GuestPanicInformationType'},
'discriminator': 'type',
'data': {'hyper-v': 'GuestPanicInformationHyperV',
- 's390': 'GuestPanicInformationS390'}}
+ 's390': 'GuestPanicInformationS390',
+ 'tdx' : 'GuestPanicInformationTdx'}}

##
# @GuestPanicInformationHyperV:
@@ -577,6 +580,26 @@
'psw-addr': 'uint64',
'reason': 'S390CrashReason'}}

+##
+# @GuestPanicInformationTdx:
+#
+# TDX GHCI TDG.VP.VMCALL<ReportFatalError> specific guest panic information
+#
+# @error-code: TD-specific error code
+#
+# @gpa: 4KB-aligned guest physical address of the page that containing
+# additional error data
+#
+# @message: TD guest provided message string. (It's not so trustable
+# and cannot be assumed to be well formed because it comes from guest)
+#
+# Since: 8.2
+##
+{'struct': 'GuestPanicInformationTdx',
+ 'data': {'error-code': 'uint64',
+ 'gpa': 'uint64',
+ 'message': 'str'}}
+
##
# @MEMORY_FAILURE:
#
diff --git a/system/runstate.c b/system/runstate.c
index ea9d6c2a32a4..9275e2f265f3 100644
--- a/system/runstate.c
+++ b/system/runstate.c
@@ -518,6 +518,52 @@ static void qemu_system_wakeup(void)
}
}

+static char* tdx_parse_panic_message(char *message)
+{
+ bool printable = false;
+ char *buf = NULL;
+ int len = 0, i;
+
+ /*
+ * Although message is defined as a json string, we shouldn't
+ * unconditionally treat it as is because the guest generated it and
+ * it's not necessarily trustable.
+ */
+ if (message) {
+ /* The caller guarantees the NUL-terminated string. */
+ len = strlen(message);
+
+ printable = len > 0;
+ for (i = 0; i < len; i++) {
+ if (!(0x20 <= message[i] && message[i] <= 0x7e)) {
+ printable = false;
+ break;
+ }
+ }
+ }
+
+ if (!printable && len) {
+ /* 3 = length of "%02x " */
+ buf = g_malloc(len * 3);
+ for (i = 0; i < len; i++) {
+ if (message[i] == '\0') {
+ break;
+ } else {
+ sprintf(buf + 3 * i, "%02x ", message[i]);
+ }
+ }
+ if (i > 0)
+ /* replace the last ' '(space) to NUL */
+ buf[i * 3 - 1] = '\0';
+ else
+ buf[0] = '\0';
+
+ return buf;
+ }
+
+ return message;
+}
+
void qemu_system_guest_panicked(GuestPanicInformation *info)
{
qemu_log_mask(LOG_GUEST_ERROR, "Guest crashed");
@@ -559,7 +605,15 @@ void qemu_system_guest_panicked(GuestPanicInformation *info)
S390CrashReason_str(info->u.s390.reason),
info->u.s390.psw_mask,
info->u.s390.psw_addr);
+ } else if (info->type == GUEST_PANIC_INFORMATION_TYPE_TDX) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ " TDX guest reports fatal error:\"%s\""
+ " error code: 0x%016" PRIx64 " gpa page: 0x%016" PRIx64 "\n",
+ tdx_parse_panic_message(info->u.tdx.message),
+ info->u.tdx.error_code,
+ info->u.tdx.gpa);
}
+
qapi_free_GuestPanicInformation(info);
}
}
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index a42b5cea36c5..23504ba3b05e 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -20,6 +20,7 @@
#include "qom/object_interfaces.h"
#include "standard-headers/asm-x86/kvm_para.h"
#include "sysemu/kvm.h"
+#include "sysemu/runstate.h"
#include "sysemu/sysemu.h"
#include "exec/address-spaces.h"
#include "exec/ramblock.h"
@@ -1479,11 +1480,26 @@ static void tdx_handle_get_quote(X86CPU *cpu, struct kvm_tdx_vmcall *vmcall)
vmcall->status_code = TDG_VP_VMCALL_SUCCESS;
}

+static void tdx_panicked_on_fatal_error(X86CPU *cpu, uint64_t error_code,
+ uint64_t gpa, char *message)
+{
+ GuestPanicInformation *panic_info;
+
+ panic_info = g_new0(GuestPanicInformation, 1);
+ panic_info->type = GUEST_PANIC_INFORMATION_TYPE_TDX;
+ panic_info->u.tdx.error_code = error_code;
+ panic_info->u.tdx.gpa = gpa;
+ panic_info->u.tdx.message = message;
+
+ qemu_system_guest_panicked(panic_info);
+}
+
static void tdx_handle_report_fatal_error(X86CPU *cpu,
struct kvm_tdx_vmcall *vmcall)
{
uint64_t error_code = vmcall->in_r12;
char *message = NULL;
+ uint64_t gpa = -1ull;

if (error_code & 0xffff) {
error_report("invalid error code of TDG.VP.VMCALL<REPORT_FATAL_ERROR>\n");
@@ -1511,8 +1527,12 @@ static void tdx_handle_report_fatal_error(X86CPU *cpu,
assert((char *)tmp == message + GUEST_PANIC_INFO_TDX_MESSAGE_MAX);
}

- error_report("TD guest reports fatal error. %s\n", message ? : "");
- exit(1);
+#define TDX_REPORT_FATAL_ERROR_GPA_VALID BIT_ULL(63)
+ if (error_code & TDX_REPORT_FATAL_ERROR_GPA_VALID) {
+ gpa = vmcall->in_r13;
+ }
+
+ tdx_panicked_on_fatal_error(cpu, error_code, gpa, message);
}

static void tdx_handle_setup_event_notify_interrupt(X86CPU *cpu,
--
2.34.1