From: Tom Lendacky <thomas.lendacky@xxxxxxx>
An SEV-ES guest does not allow register state to be altered once it has
been measured. When a SEV-ES guest issues a reboot command, Qemu will
reset the vCPU state and resume the guest. This will cause failures under
SEV-ES, so prevent that from occurring.
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
accel/kvm/kvm-all.c | 9 +++++++++
include/sysemu/cpus.h | 2 ++
include/sysemu/hw_accel.h | 5 +++++
include/sysemu/kvm.h | 2 ++
softmmu/cpus.c | 5 +++++
softmmu/vl.c | 5 ++++-
6 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 20725b0368..63153b6e53 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2388,6 +2388,15 @@ void kvm_flush_coalesced_mmio_buffer(void)
s->coalesced_flush_in_progress = false;
}
+bool kvm_cpu_check_resettable(void)
+{
+ /*
+ * If we have a valid reset vector override, then SEV-ES is active
+ * and the CPU can't be reset.
+ */
+ return !kvm_state->reset_valid;
+}
+
static void do_kvm_cpu_synchronize_state(CPUState *cpu, run_on_cpu_data arg)
{
if (!cpu->vcpu_dirty) {
diff --git a/include/sysemu/cpus.h b/include/sysemu/cpus.h
index 3c1da6a018..6d688c757f 100644
--- a/include/sysemu/cpus.h
+++ b/include/sysemu/cpus.h
@@ -24,6 +24,8 @@ void dump_drift_info(void);
void qemu_cpu_kick_self(void);
void qemu_timer_notify_cb(void *opaque, QEMUClockType type);
+bool cpu_is_resettable(void);
+
void cpu_synchronize_all_states(void);
void cpu_synchronize_all_post_reset(void);
void cpu_synchronize_all_post_init(void);
diff --git a/include/sysemu/hw_accel.h b/include/sysemu/hw_accel.h
index e128f8b06b..8b4536e7ae 100644
--- a/include/sysemu/hw_accel.h
+++ b/include/sysemu/hw_accel.h
@@ -17,6 +17,11 @@
#include "sysemu/hvf.h"
#include "sysemu/whpx.h"
+static inline bool cpu_check_resettable(void)
+{
+ return kvm_enabled() ? kvm_cpu_check_resettable() : true;
+}
+
static inline void cpu_synchronize_state(CPUState *cpu)
{
if (kvm_enabled()) {
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index f74cfa85ab..eb94bbbff9 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -494,6 +494,8 @@ int kvm_physical_memory_addr_from_host(KVMState *s, void *ram_addr,
#endif /* NEED_CPU_H */
+bool kvm_cpu_check_resettable(void);
+
void kvm_cpu_synchronize_state(CPUState *cpu);
void kvm_cpu_synchronize_post_reset(CPUState *cpu);
void kvm_cpu_synchronize_post_init(CPUState *cpu);
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index a802e899ab..32f286643f 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -927,6 +927,11 @@ void hw_error(const char *fmt, ...)
abort();
}
+bool cpu_is_resettable(void)
+{
+ return cpu_check_resettable();
+}
+
void cpu_synchronize_all_states(void)
{
CPUState *cpu;
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 4eb9d1f7fd..422fbb1650 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1475,7 +1475,10 @@ void qemu_system_guest_crashloaded(GuestPanicInformation *info)
void qemu_system_reset_request(ShutdownCause reason)
{
- if (no_reboot && reason != SHUTDOWN_CAUSE_SUBSYSTEM_RESET) {
+ if (!cpu_is_resettable()) {
+ error_report("cpus are not resettable, terminating");
+ shutdown_requested = reason;
+ } else if (no_reboot && reason != SHUTDOWN_CAUSE_SUBSYSTEM_RESET) {
shutdown_requested = reason;
} else {
reset_requested = reason;
--
2.28.0
