[PATCH 8/11] QEMU/KVM: Support for SMP guest debugging

[Jan Kiszka <jan.kiszka@web.de>]

Enables debugging of SMP guests via the new KVM debug interface. It
updates the monitored CPU on breakpoints and unsures that breakpoint
changes are propagested to all virtual CPUs.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
---
 qemu/qemu-kvm.c |   24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

Index: b/qemu/qemu-kvm.c
===================================================================
--- a/qemu/qemu-kvm.c
+++ b/qemu/qemu-kvm.c
@@ -19,6 +19,7 @@ int kvm_pit = 1;
 #include "qemu-common.h"
 #include "console.h"
 #include "block.h"
+#include "monitor.h"
 
 #include "qemu-kvm.h"
 #include <libkvm.h>
@@ -58,7 +59,7 @@ pthread_t io_thread;
 static int io_thread_fd = -1;
 static int io_thread_sigfd = -1;
 
-static int kvm_debug_stop_requested;
+static CPUState *kvm_debug_cpu_requested;
 
 static inline unsigned long kvm_get_thread_id(void)
 {
@@ -534,9 +535,10 @@ int kvm_main_loop(void)
             qemu_system_powerdown();
         else if (qemu_reset_requested())
 	    qemu_kvm_system_reset();
-	else if (kvm_debug_stop_requested) {
+	else if (kvm_debug_cpu_requested) {
+	    mon_set_cpu(kvm_debug_cpu_requested);
 	    vm_stop(EXCP_DEBUG);
-	    kvm_debug_stop_requested = 0;
+	    kvm_debug_cpu_requested = NULL;
 	}
     }
 
@@ -552,7 +554,7 @@ int kvm_debug(void *opaque, int vcpu, st
     int handle = kvm_arch_debug(arch_info);
 
     if (handle) {
-	kvm_debug_stop_requested = 1;
+	kvm_debug_cpu_requested = cpu_single_env;
 	vcpu_info[vcpu].stopped = 1;
     }
     return handle;
@@ -846,7 +848,12 @@ int kvm_insert_breakpoint(CPUState *env,
 	if (err)
 	    return err;
     }
-    return kvm_update_guest_debug(env, 0);
+    foreach_cpu(env) {
+	err = kvm_update_guest_debug(env, 0);
+	if (err)
+	    break;
+    }
+    return err;
 }
 
 int kvm_remove_breakpoint(CPUState *env, target_ulong addr,
@@ -882,7 +889,12 @@ int kvm_remove_breakpoint(CPUState *env,
 	if (err)
 	    return err;
     }
-    return kvm_update_guest_debug(env, 0);
+    foreach_cpu(env) {
+	err = kvm_update_guest_debug(env, 0);
+	if (err)
+	    break;
+    }
+    return err;
 }
 
 #else /* !KVM_CAP_SET_GUEST_DEBUG */