[Qemu-devel] [PATCH v4 0/2] qemu-kvm: Save&restore debug registers

[Qemu-devel] [PATCH v4 0/2] qemu-kvm: Save&restore debug registers

[Jan Kiszka]

Patch 1 is for upstream and should be applied to uq/master as well, patch
2 is for qemu-kvm only.

Jan Kiszka (2):
  KVM: x86: Add debug register saving and restoring
  qemu-kvm: x86: Add support for saving&restoring debug registers

 kvm-all.c         |   11 ++++++++++
 kvm.h             |    1 +
 qemu-kvm-x86.c    |    2 +
 qemu-kvm.c        |    5 ++++
 qemu-kvm.h        |    1 +
 target-i386/kvm.c |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 75 insertions(+), 0 deletions(-)

[Qemu-devel] [PATCH v4 1/2] KVM: x86: Add debug register saving and restoring

[Jan Kiszka]

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>
---
 kvm-all.c         |   11 ++++++++++
 kvm.h             |    1 +
 target-i386/kvm.c |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 0 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 8ca480d..c469b6a 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -67,6 +67,7 @@ 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
@@ -676,6 +677,11 @@ 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;
@@ -955,6 +961,11 @@ 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()) {
diff --git a/kvm.h b/kvm.h
index b0d07c8..c6faf20 100644
--- a/kvm.h
+++ b/kvm.h
@@ -44,6 +44,7 @@ int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size);
 int kvm_has_sync_mmu(void);
 int kvm_has_vcpu_events(void);
 int kvm_has_robust_singlestep(void);
+int kvm_has_debugregs(void);
 
 void kvm_cpu_register_phys_memory_client(void);
 
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 123dcc8..b5c3c27 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -903,6 +903,53 @@ static int kvm_guest_debug_workarounds(CPUState *env)
 }
 
 #ifdef KVM_UPSTREAM
+static int kvm_put_debugregs(CPUState *env)
+{
+#ifdef KVM_CAP_DEBUGREGS
+    struct kvm_debugregs dbgregs;
+    int i;
+
+    if (!kvm_has_debugregs()) {
+        return 0;
+    }
+
+    for (i = 0; i < 4; i++) {
+        dbgregs.db[i] = env->dr[i];
+    }
+    dbgregs.dr6 = env->dr[6];
+    dbgregs.dr7 = env->dr[7];
+    dbgregs.flags = 0;
+
+    return kvm_vcpu_ioctl(env, KVM_SET_DEBUGREGS, &dbgregs);
+#else
+    return 0;
+#endif
+}
+
+static int kvm_get_debugregs(CPUState *env)
+{
+#ifdef KVM_CAP_DEBUGREGS
+    struct kvm_debugregs dbgregs;
+    int i, ret;
+
+    if (!kvm_has_debugregs()) {
+        return 0;
+    }
+
+    ret = kvm_vcpu_ioctl(env, KVM_GET_DEBUGREGS, &dbgregs);
+    if (ret < 0) {
+       return ret;
+    }
+    for (i = 0; i < 4; i++) {
+        env->dr[i] = dbgregs.db[i];
+    }
+    env->dr[4] = env->dr[6] = dbgregs.dr6;
+    env->dr[5] = env->dr[7] = dbgregs.dr7;
+#endif
+
+    return 0;
+}
+
 int kvm_arch_put_registers(CPUState *env, int level)
 {
     int ret;
@@ -938,6 +985,10 @@ int kvm_arch_put_registers(CPUState *env, int level)
     if (ret < 0)
         return ret;
 
+    ret = kvm_put_debugregs(env);
+    if (ret < 0)
+        return ret;
+
     return 0;
 }
 
@@ -969,6 +1020,10 @@ int kvm_arch_get_registers(CPUState *env)
     if (ret < 0)
         return ret;
 
+    ret = kvm_get_debugregs(env);
+    if (ret < 0)
+        return ret;
+
     return 0;
 }
 
-- 
1.6.0.2

[Qemu-devel] [PATCH v4 2/2] qemu-kvm: x86: Add support for saving&restoring debug registers

[Jan Kiszka]

Corresponding support for qemu-kvm.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 qemu-kvm-x86.c    |    2 ++
 qemu-kvm.c        |    5 +++++
 qemu-kvm.h        |    1 +
 target-i386/kvm.c |    2 +-
 4 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index 0160fe9..65a3cfc 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -1012,6 +1012,7 @@ void kvm_arch_load_regs(CPUState *env, int level)
     }
 
     kvm_put_vcpu_events(env, level);
+    kvm_put_debugregs(env);
 
     /* must be last */
     kvm_guest_debug_workarounds(env);
@@ -1185,6 +1186,7 @@ void kvm_arch_save_regs(CPUState *env)
     kvm_arch_save_mpstate(env);
     kvm_save_lapic(env);
     kvm_get_vcpu_events(env);
+    kvm_get_debugregs(env);
 }
 
 static void do_cpuid_ent(struct kvm_cpuid_entry2 *e, uint32_t function,
diff --git a/qemu-kvm.c b/qemu-kvm.c
index e417f21..0e7d594 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -2115,6 +2115,11 @@ static int kvm_create_context(void)
     kvm_state->vcpu_events = kvm_check_extension(kvm_state, KVM_CAP_VCPU_EVENTS);
 #endif
 
+    kvm_state->debugregs = 0;
+#ifdef KVM_CAP_DEBUGREGS
+    kvm_state->debugregs = kvm_check_extension(kvm_state, KVM_CAP_DEBUGREGS);
+#endif
+
     kvm_init_ap();
     if (kvm_irqchip) {
         if (!qemu_kvm_has_gsi_routing()) {
diff --git a/qemu-kvm.h b/qemu-kvm.h
index f5db9e6..0cbc6f7 100644
--- a/qemu-kvm.h
+++ b/qemu-kvm.h
@@ -970,6 +970,7 @@ struct KVMState {
     int migration_log;
     int vcpu_events;
     int robust_singlestep;
+    int debugregs;
 #ifdef KVM_CAP_SET_GUEST_DEBUG
     QTAILQ_HEAD(, kvm_sw_breakpoint) kvm_sw_breakpoints;
 #endif
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index b5c3c27..8d00774 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -902,7 +902,6 @@ static int kvm_guest_debug_workarounds(CPUState *env)
     return ret;
 }
 
-#ifdef KVM_UPSTREAM
 static int kvm_put_debugregs(CPUState *env)
 {
 #ifdef KVM_CAP_DEBUGREGS
@@ -950,6 +949,7 @@ static int kvm_get_debugregs(CPUState *env)
     return 0;
 }
 
+#ifdef KVM_UPSTREAM
 int kvm_arch_put_registers(CPUState *env, int level)
 {
     int ret;
-- 
1.6.0.2

[Qemu-devel] Re: [PATCH v4 0/2] qemu-kvm: Save&restore debug registers

[Marcelo Tosatti]

On Fri, Mar 12, 2010 at 03:20:48PM +0100, Jan Kiszka wrote:
> Patch 1 is for upstream and should be applied to uq/master as well, patch
> 2 is for qemu-kvm only.
> 
> Jan Kiszka (2):
>   KVM: x86: Add debug register saving and restoring
>   qemu-kvm: x86: Add support for saving&restoring debug registers
> 
>  kvm-all.c         |   11 ++++++++++
>  kvm.h             |    1 +
>  qemu-kvm-x86.c    |    2 +
>  qemu-kvm.c        |    5 ++++
>  qemu-kvm.h        |    1 +
>  target-i386/kvm.c |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  6 files changed, 75 insertions(+), 0 deletions(-)

Applied, thanks.