[Qemu-devel] [PATCH v2] introduce on_vcpu

[Qemu-devel] [PATCH v2] introduce on_vcpu

[Glauber Costa]

on_vcpu is a qemu-kvm function that will make sure that a specific
piece of code will run on a requested cpu. We don't need that because
we're restricted to -smp 1 right now, but those days are likely to end soon.

So for the benefit of having qemu-kvm share more code with us, I'm
introducing our own version of on_vcpu(). Right now, we either run
a function on the current cpu, or abort the execution, because it would
mean something is seriously wrong.

As an example code, I "ported" kvm_update_guest_debug to use it,
with some slight differences from qemu-kvm.

This is probably 0.12 material

Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Jan Kiszka <jan.kiszka@siemens.com>
---
 kvm-all.c |   37 +++++++++++++++++++++++++++++++------
 1 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 61194b8..0c881e8 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -39,6 +39,8 @@
     do { } while (0)
 #endif
 
+CPUState *current_env;
+
 typedef struct KVMSlot
 {
     target_phys_addr_t start_addr;
@@ -155,6 +157,15 @@ static void kvm_reset_vcpu(void *opaque)
     }
 }
 
+static void on_vcpu(CPUState *env, void (*func)(void *data), void *data)
+{
+    if (env == cpu_single_env) {
+        func(data);
+        return;
+    }
+    abort();
+}
+
 int kvm_init_vcpu(CPUState *env)
 {
     KVMState *s = kvm_state;
@@ -892,18 +903,32 @@ int kvm_sw_breakpoints_active(CPUState *env)
     return !TAILQ_EMPTY(&env->kvm_state->kvm_sw_breakpoints);
 }
 
+struct kvm_set_guest_debug_data {
+    struct kvm_guest_debug dbg;
+    CPUState *env;
+    int err;
+};
+
+static void kvm_invoke_set_guest_debug(void *data)
+{
+    struct kvm_set_guest_debug_data *dbg_data = data;
+    dbg_data->err = kvm_vcpu_ioctl(dbg_data->env, KVM_SET_GUEST_DEBUG, &dbg_data->dbg);
+}
+
 int kvm_update_guest_debug(CPUState *env, unsigned long reinject_trap)
 {
-    struct kvm_guest_debug dbg;
+    struct kvm_set_guest_debug_data data;
 
-    dbg.control = 0;
+    data.dbg.control = 0;
     if (env->singlestep_enabled)
-        dbg.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
+        data.dbg.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
 
-    kvm_arch_update_guest_debug(env, &dbg);
-    dbg.control |= reinject_trap;
+    kvm_arch_update_guest_debug(env, &data.dbg);
+    data.dbg.control |= reinject_trap;
+    data.env = env;
 
-    return kvm_vcpu_ioctl(env, KVM_SET_GUEST_DEBUG, &dbg);
+    on_vcpu(env, kvm_invoke_set_guest_debug, &data);
+    return data.err;
 }
 
 int kvm_insert_breakpoint(CPUState *current_env, target_ulong addr,
-- 
1.6.2.2

[Qemu-devel] Re: [PATCH v2] introduce on_vcpu

[Anthony Liguori]

Glauber Costa wrote:
> on_vcpu is a qemu-kvm function that will make sure that a specific
> piece of code will run on a requested cpu. We don't need that because
> we're restricted to -smp 1 right now, but those days are likely to end soon.
>
> So for the benefit of having qemu-kvm share more code with us, I'm
> introducing our own version of on_vcpu(). Right now, we either run
> a function on the current cpu, or abort the execution, because it would
> mean something is seriously wrong.
>
> As an example code, I "ported" kvm_update_guest_debug to use it,
> with some slight differences from qemu-kvm.
>
> This is probably 0.12 material
>
> Signed-off-by: Glauber Costa <glommer@redhat.com>
> CC: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  kvm-all.c |   37 +++++++++++++++++++++++++++++++------
>  1 files changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/kvm-all.c b/kvm-all.c
> index 61194b8..0c881e8 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -39,6 +39,8 @@
>      do { } while (0)
>  #endif
>
> +CPUState *current_env;
> +
>   

That shouldn't be there anymore...

-- 
Regards,

Anthony Liguori

[Qemu-devel] Re: [PATCH v2] introduce on_vcpu

[Glauber Costa]

On Thu, Jul 16, 2009 at 04:35:46PM -0500, Anthony Liguori wrote:
> Glauber Costa wrote:
>> on_vcpu is a qemu-kvm function that will make sure that a specific
>> piece of code will run on a requested cpu. We don't need that because
>> we're restricted to -smp 1 right now, but those days are likely to end soon.
>>
>> So for the benefit of having qemu-kvm share more code with us, I'm
>> introducing our own version of on_vcpu(). Right now, we either run
>> a function on the current cpu, or abort the execution, because it would
>> mean something is seriously wrong.
>>
>> As an example code, I "ported" kvm_update_guest_debug to use it,
>> with some slight differences from qemu-kvm.
>>
>> This is probably 0.12 material
>>
>> Signed-off-by: Glauber Costa <glommer@redhat.com>
>> CC: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>>  kvm-all.c |   37 +++++++++++++++++++++++++++++++------
>>  1 files changed, 31 insertions(+), 6 deletions(-)
>>
>> diff --git a/kvm-all.c b/kvm-all.c
>> index 61194b8..0c881e8 100644
>> --- a/kvm-all.c
>> +++ b/kvm-all.c
>> @@ -39,6 +39,8 @@
>>      do { } while (0)
>>  #endif
>>
>> +CPUState *current_env;
>> +
>>   
>
> That shouldn't be there anymore...
oops ;-)

>
> -- 
> Regards,
>
> Anthony Liguori
>