[PATCH 5/5] kvm: add support for KVM_GUESTDBG_BLOCKIRQ

[Paolo Bonzini <pbonzini@redhat.com>]

From: Maxim Levitsky <mlevitsk@redhat.com>

Use the KVM_GUESTDBG_BLOCKIRQ debug flag if supported. 

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
[Extracted from Maxim's patch into a separate commit. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 accel/kvm/kvm-all.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 2f5597572a..0e66ebb497 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -61,6 +61,10 @@
 #endif
 #define PAGE_SIZE qemu_real_host_page_size
 
+#ifndef KVM_GUESTDBG_BLOCKIRQ
+#define KVM_GUESTDBG_BLOCKIRQ 0
+#endif
+
 //#define DEBUG_KVM
 
 #ifdef DEBUG_KVM
@@ -2574,6 +2578,15 @@ static int kvm_init(MachineState *ms)
     kvm_sstep_flags = 0;
     if (kvm_has_guest_debug) {
         kvm_sstep_flags = SSTEP_ENABLE;
+
+#if defined KVM_CAP_SET_GUEST_DEBUG2
+        int guest_debug_flags =
+            kvm_check_extension(s, KVM_CAP_SET_GUEST_DEBUG2);
+
+        if (guest_debug_flags & KVM_GUESTDBG_BLOCKIRQ) {
+            kvm_sstep_flags |= SSTEP_NOIRQ;
+        }
+#endif
     }
 
     kvm_state = s;
@@ -3205,6 +3218,10 @@ int kvm_update_guest_debug(CPUState *cpu, unsigned long reinject_trap)
 
     if (cpu->singlestep_enabled) {
         data.dbg.control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
+
+        if (cpu->singlestep_enabled & SSTEP_NOIRQ) {
+            data.dbg.control |= KVM_GUESTDBG_BLOCKIRQ;
+        }
     }
     kvm_arch_update_guest_debug(cpu, &data.dbg);
 
-- 
2.33.1