KVM: x86: Add debug register saving and restoring

Make use of the new KVM_GET/SET_DEBUGREGS to save/restore the x86 debug
registers.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/kvm-all.c b/kvm-all.c
index 2ede4b9ea7..d05011547d 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -64,6 +64,7 @@ struct KVMState
     int migration_log;
     int vcpu_events;
     int robust_singlestep;
+    int debugregs;
 #ifdef KVM_CAP_SET_GUEST_DEBUG
     struct kvm_sw_breakpoint_head kvm_sw_breakpoints;
 #endif
@@ -664,6 +665,11 @@ int kvm_init(int smp_cpus)
         kvm_check_extension(s, KVM_CAP_X86_ROBUST_SINGLESTEP);
 #endif
 
+    s->debugregs = 0;
+#ifdef KVM_CAP_DEBUGREGS
+    s->debugregs = kvm_check_extension(s, KVM_CAP_DEBUGREGS);
+#endif
+
     ret = kvm_arch_init(s, smp_cpus);
     if (ret < 0)
         goto err;
@@ -939,6 +945,11 @@ int kvm_has_robust_singlestep(void)
     return kvm_state->robust_singlestep;
 }
 
+int kvm_has_debugregs(void)
+{
+    return kvm_state->debugregs;
+}
+
 void kvm_setup_guest_memory(void *start, size_t size)
 {
     if (!kvm_has_sync_mmu()) {