| Message ID | 20230127150727.612594-16-jean-philippe@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | arm: Run Arm CCA VMs with KVM | expand |
On 1/27/23 05:07, Jean-Philippe Brucker wrote: > A realm cannot be reset, it must be recreated from scratch. The RMM > specification defines states of a Realm as NEW -> ACTIVE -> SYSTEM_OFF, > after which the Realm can only be destroyed. A PCSI_SYSTEM_RESET call, > which normally reboots the system, puts the Realm in SYSTEM_OFF state. > > QEMU does not support recreating a VM. Normally, a reboot request by the > guest causes all devices to reset, which cannot work for a Realm. > Indeed, loading images into Realm memory and changing the PC is only > allowed for a Realm in NEW state. Resetting the images for a Realm in > SYSTEM_OFF state will cause QEMU to crash with a bus error. > > Handle reboot requests by the guest more gracefully, by indicating to > runstate.c that the vCPUs of a Realm are not resettable, and that QEMU > should exit. > > Signed-off-by: Jean-Philippe Brucker<jean-philippe@linaro.org> > --- > target/arm/kvm.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/target/arm/kvm.c b/target/arm/kvm.c index d8655d9041..02b5e8009f 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -1071,7 +1071,8 @@ int kvm_arch_msi_data_to_gsi(uint32_t data) bool kvm_arch_cpu_check_are_resettable(void) { - return true; + /* A Realm cannot be reset */ + return !kvm_arm_rme_enabled(); } void kvm_arch_accel_class_init(ObjectClass *oc)
A realm cannot be reset, it must be recreated from scratch. The RMM specification defines states of a Realm as NEW -> ACTIVE -> SYSTEM_OFF, after which the Realm can only be destroyed. A PCSI_SYSTEM_RESET call, which normally reboots the system, puts the Realm in SYSTEM_OFF state. QEMU does not support recreating a VM. Normally, a reboot request by the guest causes all devices to reset, which cannot work for a Realm. Indeed, loading images into Realm memory and changing the PC is only allowed for a Realm in NEW state. Resetting the images for a Realm in SYSTEM_OFF state will cause QEMU to crash with a bus error. Handle reboot requests by the guest more gracefully, by indicating to runstate.c that the vCPUs of a Realm are not resettable, and that QEMU should exit. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> --- target/arm/kvm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)