cpu: Don't set vcpu_dirty when guest_state_protected

QEMU calls kvm_arch_put_registers() when vcpu_dirty is true in
kvm_vcpu_exec(). However, for confidential guest, like TDX, putting
registers is disallowed due to guest state is protected.

Only set vcpu_dirty to true with guest state is not protected when
creating the vcpu.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-43-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 71e6060458560a03708452a474fcd86d837943d4..51526d301b9a4ec15652962f15cfa854b3921bb4 100644 (file)
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -471,7 +471,9 @@ int kvm_create_vcpu(CPUState *cpu)
 
     cpu->kvm_fd = kvm_fd;
     cpu->kvm_state = s;
-    cpu->vcpu_dirty = true;
+    if (!s->guest_state_protected) {
+        cpu->vcpu_dirty = true;
+    }
     cpu->dirty_pages = 0;
     cpu->throttle_us_per_full = 0;