Index: kvm/drivers/kvm/kvm.h
===================================================================
--- kvm.orig/drivers/kvm/kvm.h 2007-08-20 13:23:53.000000000 +0200
+++ kvm/drivers/kvm/kvm.h 2007-08-20 13:23:58.000000000 +0200
@@ -589,6 +589,17 @@ void kvm_mmu_unload(struct kvm_vcpu *vcp
int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);
+static inline void kvm_guest_enter(void)
+{
+#ifdef CONFIG_GUEST_ACCOUNTING
+ current->flags |= PF_VCPU;
+#endif
+}
+
+static inline void kvm_guest_exit(void)
+{
+}
+
static inline int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
u32 error_code)
{
Index: kvm/drivers/kvm/svm.c
===================================================================
--- kvm.orig/drivers/kvm/svm.c 2007-08-20 13:23:53.000000000 +0200
+++ kvm/drivers/kvm/svm.c 2007-08-20 13:23:58.000000000 +0200
@@ -1404,6 +1404,7 @@ again:
clgi();
vcpu->guest_mode = 1;
+ kvm_guest_enter();
if (vcpu->requests)
if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
svm_flush_tlb(vcpu);
@@ -1536,6 +1537,7 @@ again:
#endif
: "cc", "memory" );
+ kvm_guest_exit();
vcpu->guest_mode = 0;
if (vcpu->fpu_active) {
Index: kvm/drivers/kvm/vmx.c
===================================================================
--- kvm.orig/drivers/kvm/vmx.c 2007-08-20 13:23:53.000000000 +0200
+++ kvm/drivers/kvm/vmx.c 2007-08-20 13:23:58.000000000 +0200
@@ -2078,6 +2078,7 @@ again:
local_irq_disable();
vcpu->guest_mode = 1;
+ kvm_guest_enter();
if (vcpu->requests)
if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
vmx_flush_tlb(vcpu);
@@ -2198,6 +2199,7 @@ again:
[cr2]"i"(offsetof(struct kvm_vcpu, cr2))
: "cc", "memory" );
+ kvm_guest_exit();
vcpu->guest_mode = 0;
local_irq_enable();
Index: kvm/drivers/kvm/Kconfig
===================================================================
--- kvm.orig/drivers/kvm/Kconfig 2007-08-20 13:36:58.000000000 +0200
+++ kvm/drivers/kvm/Kconfig 2007-08-20 13:37:36.000000000 +0200
@@ -13,6 +13,7 @@ config KVM
depends on X86 && EXPERIMENTAL
select PREEMPT_NOTIFIERS
select ANON_INODES
+ select GUEST_ACCOUNTING
---help---
Support hosting fully virtualized guest machines using hardware
virtualization extensions. You will need a fairly recent
Laurent Vivier wrote:
> [PATCH 4/4] Modify KVM to update guest time accounting.
>
>
> Index: kvm/drivers/kvm/kvm.h
> ===================================================================
> --- kvm.orig/drivers/kvm/kvm.h 2007-08-20 13:23:53.000000000 +0200
> +++ kvm/drivers/kvm/kvm.h 2007-08-20 13:23:58.000000000 +0200
> @@ -589,6 +589,17 @@ void kvm_mmu_unload(struct kvm_vcpu *vcp
>
> int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);
>
> +static inline void kvm_guest_enter(void)
> +{
> +#ifdef CONFIG_GUEST_ACCOUNTING
> + current->flags |= PF_VCPU;
> +#endif
>
Since you select GUEST_ACCOUNTING, the #ifdef is always true?
> +}
> +
> +static inline void kvm_guest_exit(void)
> +{
>
Missing content?
--
error compiling committee.c: too many arguments to function
Avi Kivity wrote:
> Laurent Vivier wrote:
>> [PATCH 4/4] Modify KVM to update guest time accounting.
>>
>>
>
>> Index: kvm/drivers/kvm/kvm.h
>> ===================================================================
>> --- kvm.orig/drivers/kvm/kvm.h 2007-08-20 13:23:53.000000000 +0200
>> +++ kvm/drivers/kvm/kvm.h 2007-08-20 13:23:58.000000000 +0200
>> @@ -589,6 +589,17 @@ void kvm_mmu_unload(struct kvm_vcpu *vcp
>>
>> int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);
>>
>> +static inline void kvm_guest_enter(void)
>> +{
>> +#ifdef CONFIG_GUEST_ACCOUNTING
>> + current->flags |= PF_VCPU;
>> +#endif
>>
>
> Since you select GUEST_ACCOUNTING, the #ifdef is always true?
It is just to avoid error if we compile kvm module outside of the kernel, with
kernel without support of guest accounting. Can be removed if you want.
>> +}
>> +
>> +static inline void kvm_guest_exit(void)
>> +{
>>
>
> Missing content?
No, empty function.
It is just to introduce "symmetry" in code, the VCPU code begins with
"kvm_guest_start()" and ends with "kvm_guest_exit()". And we have no operation
to do in kvm_guest_exit() (the PF_VCPU is cleared by account_system_time()), so
"empty function", removed by the optimizer (I hope).
Laurent
--
------------- [email protected] --------------
"Software is hard" - Donald Knuth
Laurent Vivier wrote:
> Avi Kivity wrote:
>
>> Laurent Vivier wrote:
>>
>>> [PATCH 4/4] Modify KVM to update guest time accounting.
>>>
>>>
>>>
>>> Index: kvm/drivers/kvm/kvm.h
>>> ===================================================================
>>> --- kvm.orig/drivers/kvm/kvm.h 2007-08-20 13:23:53.000000000 +0200
>>> +++ kvm/drivers/kvm/kvm.h 2007-08-20 13:23:58.000000000 +0200
>>> @@ -589,6 +589,17 @@ void kvm_mmu_unload(struct kvm_vcpu *vcp
>>>
>>> int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);
>>>
>>> +static inline void kvm_guest_enter(void)
>>> +{
>>> +#ifdef CONFIG_GUEST_ACCOUNTING
>>> + current->flags |= PF_VCPU;
>>> +#endif
>>>
>>>
>> Since you select GUEST_ACCOUNTING, the #ifdef is always true?
>>
>
> It is just to avoid error if we compile kvm module outside of the kernel, with
> kernel without support of guest accounting. Can be removed if you want.
>
>
Ah okay. We take care of the external module in
external-module-compat.h (in this case, we can #define PF_VCPU to 0 if
it is undefined).
>>> +}
>>> +
>>> +static inline void kvm_guest_exit(void)
>>> +{
>>>
>>>
>> Missing content?
>>
>
> No, empty function.
>
> It is just to introduce "symmetry" in code, the VCPU code begins with
> "kvm_guest_start()" and ends with "kvm_guest_exit()". And we have no operation
> to do in kvm_guest_exit() (the PF_VCPU is cleared by account_system_time()), so
> "empty function", removed by the optimizer (I hope).
>
But what if account_system_time() is not called (because we exited
before the timer interrupt hit)?
--
error compiling committee.c: too many arguments to function
Avi Kivity wrote:
> Laurent Vivier wrote:
>> Avi Kivity wrote:
>>
>>> Laurent Vivier wrote:
>>>
>>>> [PATCH 4/4] Modify KVM to update guest time accounting.
>>>>
>>>>
>>>>
>>>> Index: kvm/drivers/kvm/kvm.h
>>>> ===================================================================
>>>> --- kvm.orig/drivers/kvm/kvm.h 2007-08-20 13:23:53.000000000 +0200
>>>> +++ kvm/drivers/kvm/kvm.h 2007-08-20 13:23:58.000000000 +0200
>>>> @@ -589,6 +589,17 @@ void kvm_mmu_unload(struct kvm_vcpu *vcp
>>>>
>>>> int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);
>>>>
>>>> +static inline void kvm_guest_enter(void)
>>>> +{
>>>> +#ifdef CONFIG_GUEST_ACCOUNTING
>>>> + current->flags |= PF_VCPU;
>>>> +#endif
>>>>
>>>>
>>> Since you select GUEST_ACCOUNTING, the #ifdef is always true?
>>>
>> It is just to avoid error if we compile kvm module outside of the kernel, with
>> kernel without support of guest accounting. Can be removed if you want.
>>
>>
>
> Ah okay. We take care of the external module in
> external-module-compat.h (in this case, we can #define PF_VCPU to 0 if
> it is undefined).
OK
>>>> +}
>>>> +
>>>> +static inline void kvm_guest_exit(void)
>>>> +{
>>>>
>>>>
>>> Missing content?
>>>
>> No, empty function.
>>
>> It is just to introduce "symmetry" in code, the VCPU code begins with
>> "kvm_guest_start()" and ends with "kvm_guest_exit()". And we have no operation
>> to do in kvm_guest_exit() (the PF_VCPU is cleared by account_system_time()), so
>> "empty function", removed by the optimizer (I hope).
>>
>
> But what if account_system_time() is not called (because we exited
> before the timer interrupt hit)?
account_system_time() is called by the scheduler on tick. If we clear PF_VCPU in
kvm_guest_exit(), the flag is always cleared when account_system_time() is
executed, so we account "0", if we call account_system_time() directly from
kvm_guest_exit() we account "1", so we subtract 1 to system time, and we have
perhaps not used 1 tick in system: in my opinion this implies wrong results.
Laurent
--
------------- [email protected] --------------
"Software is hard" - Donald Knuth