On 9/23/22 09:33, Chenyi Qiang wrote:
For the direct triple faults, i.e. hardware detected and KVM morphed
to VM-Exit, KVM will never lose them. But for triple faults sythesized
by KVM, e.g. the RSM path, if KVM exits to userspace before the request
is serviced, userspace could migrate the VM and lose the triple fault.
A new flag KVM_VCPUEVENT_VALID_TRIPLE_FAULT is defined to signal that
the event.triple_fault_pending field contains a valid state if the
KVM_CAP_X86_TRIPLE_FAULT_EVENT capability is enabled.
Note that you are not transmitting the field on migration. You need
this on top:
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index b97d182e28..d4124973ce 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1739,7 +1739,7 @@ typedef struct CPUArchState {
uint8_t has_error_code;
uint8_t exception_has_payload;
uint64_t exception_payload;
- bool triple_fault_pending;
+ uint8_t triple_fault_pending;
uint32_t ins_len;
uint32_t sipi_vector;
bool tsc_valid;
diff --git a/target/i386/machine.c b/target/i386/machine.c
index cecd476e98..310b125235 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -1562,6 +1562,25 @@ static const VMStateDescription vmstate_arch_lbr = {
}
};
+static bool triple_fault_needed(void *opaque)
+{
+ X86CPU *cpu = opaque;
+ CPUX86State *env = &cpu->env;
+
+ return env->triple_fault_pending;
+}
+
+static const VMStateDescription vmstate_triple_fault = {
+ .name = "cpu/triple_fault",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = triple_fault_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT8(env.triple_fault_pending, X86CPU),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
const VMStateDescription vmstate_x86_cpu = {
.name = "cpu",
.version_id = 12,
@@ -1706,6 +1725,7 @@ const VMStateDescription vmstate_x86_cpu = {
&vmstate_amx_xtile,
#endif
&vmstate_arch_lbr,
+ &vmstate_triple_fault,
NULL
}
};