2021-08-15 01:03:23

by Gavin Shan

Subject: [PATCH v4 01/15] KVM: async_pf: Move struct kvm_async_pf around

This moves the definition of "struct kvm_async_pf" and the related
functions after "struct kvm_vcpu" so that newly added inline functions
in the subsequent patches can dereference "struct kvm_vcpu" properly.
Otherwise, the unexpected build error will be raised:

error: dereferencing pointer to incomplete type ‘struct kvm_vcpu’
return !list_empty_careful(&vcpu->async_pf.done);
^~
Since we're here, the sepator between type and field in "struct kvm_vcpu"
is replaced by tab. The empty stub kvm_check_async_pf_completion() is also
added on !CONFIG_KVM_ASYNC_PF, which is needed by subsequent patches to
support asynchronous page fault on ARM64.

Signed-off-by: Gavin Shan <[email protected]>
---
include/linux/kvm_host.h | 44 +++++++++++++++++++++-------------------
1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ae7735b490b4..85b61a456f1c 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -199,27 +199,6 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
gpa_t addr);

-#ifdef CONFIG_KVM_ASYNC_PF
-struct kvm_async_pf {
- struct work_struct work;
- struct list_head link;
- struct list_head queue;
- struct kvm_vcpu *vcpu;
- struct mm_struct *mm;
- gpa_t cr2_or_gpa;
- unsigned long addr;
- struct kvm_arch_async_pf arch;
- bool wakeup_all;
- bool notpresent_injected;
-};
-
-void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
-void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
-bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
- unsigned long hva, struct kvm_arch_async_pf *arch);
-int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
-#endif
-
#ifdef KVM_ARCH_WANT_MMU_NOTIFIER
struct kvm_gfn_range {
struct kvm_memory_slot *slot;
@@ -346,6 +325,29 @@ struct kvm_vcpu {
struct kvm_dirty_ring dirty_ring;
};

+#ifdef CONFIG_KVM_ASYNC_PF
+struct kvm_async_pf {
+ struct work_struct work;
+ struct list_head link;
+ struct list_head queue;
+ struct kvm_vcpu *vcpu;
+ struct mm_struct *mm;
+ gpa_t cr2_or_gpa;
+ unsigned long addr;
+ struct kvm_arch_async_pf arch;
+ bool wakeup_all;
+ bool notpresent_injected;
+};
+
+void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
+void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
+bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
+ unsigned long hva, struct kvm_arch_async_pf *arch);
+int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
+#else
+static inline void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu) { }
+#endif
+
/* must be called with irqs disabled */
static __always_inline void guest_enter_irqoff(void)
{
--
2.23.0

2021-11-10 15:41:13

by Eric Auger

Subject: Re: [PATCH v4 01/15] KVM: async_pf: Move struct kvm_async_pf around

Hi Gavin,

On 8/15/21 2:59 AM, Gavin Shan wrote:
> This moves the definition of "struct kvm_async_pf" and the related
> functions after "struct kvm_vcpu" so that newly added inline functions
> in the subsequent patches can dereference "struct kvm_vcpu" properly.
> Otherwise, the unexpected build error will be raised:
>
> error: dereferencing pointer to incomplete type ‘struct kvm_vcpu’
> return !list_empty_careful(&vcpu->async_pf.done);
> ^~
> Since we're here, the sepator between type and field in "struct kvm_vcpu"
separator
> is replaced by tab. The empty stub kvm_check_async_pf_completion() is also
> added on !CONFIG_KVM_ASYNC_PF, which is needed by subsequent patches to
> support asynchronous page fault on ARM64.
>
> Signed-off-by: Gavin Shan <[email protected]>
> ---
> include/linux/kvm_host.h | 44 +++++++++++++++++++++-------------------
> 1 file changed, 23 insertions(+), 21 deletions(-)
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index ae7735b490b4..85b61a456f1c 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -199,27 +199,6 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
> struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
> gpa_t addr);
>
> -#ifdef CONFIG_KVM_ASYNC_PF
> -struct kvm_async_pf {
> - struct work_struct work;
> - struct list_head link;
> - struct list_head queue;
> - struct kvm_vcpu *vcpu;
> - struct mm_struct *mm;
> - gpa_t cr2_or_gpa;
> - unsigned long addr;
> - struct kvm_arch_async_pf arch;
> - bool wakeup_all;
> - bool notpresent_injected;
> -};
> -
> -void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
> -void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
> -bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
> - unsigned long hva, struct kvm_arch_async_pf *arch);
> -int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
> -#endif
> -
> #ifdef KVM_ARCH_WANT_MMU_NOTIFIER
> struct kvm_gfn_range {
> struct kvm_memory_slot *slot;
> @@ -346,6 +325,29 @@ struct kvm_vcpu {
> struct kvm_dirty_ring dirty_ring;
> };
>
> +#ifdef CONFIG_KVM_ASYNC_PF
> +struct kvm_async_pf {
> + struct work_struct work;
> + struct list_head link;
> + struct list_head queue;
> + struct kvm_vcpu *vcpu;
> + struct mm_struct *mm;
> + gpa_t cr2_or_gpa;
> + unsigned long addr;
> + struct kvm_arch_async_pf arch;
> + bool wakeup_all;
> + bool notpresent_injected;
> +};
> +
> +void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
> +void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
> +bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
> + unsigned long hva, struct kvm_arch_async_pf *arch);
> +int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
> +#else
> +static inline void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu) { }
why is that stub needed on ARM64 and not on the other archs?

Eric
> +#endif
> +
> /* must be called with irqs disabled */
> static __always_inline void guest_enter_irqoff(void)
> {
>

2022-01-13 07:21:44

by Gavin Shan

Subject: Re: [PATCH v4 01/15] KVM: async_pf: Move struct kvm_async_pf around

Hi Eric,

On 11/10/21 11:37 PM, Eric Auger wrote:
> On 8/15/21 2:59 AM, Gavin Shan wrote:
>> This moves the definition of "struct kvm_async_pf" and the related
>> functions after "struct kvm_vcpu" so that newly added inline functions
>> in the subsequent patches can dereference "struct kvm_vcpu" properly.
>> Otherwise, the unexpected build error will be raised:
>>
>> error: dereferencing pointer to incomplete type ‘struct kvm_vcpu’
>> return !list_empty_careful(&vcpu->async_pf.done);
>> ^~
>> Since we're here, the sepator between type and field in "struct kvm_vcpu"
> separator

Thanks, It will be fixed in next respin.

>> is replaced by tab. The empty stub kvm_check_async_pf_completion() is also
>> added on !CONFIG_KVM_ASYNC_PF, which is needed by subsequent patches to
>> support asynchronous page fault on ARM64.
>>
>> Signed-off-by: Gavin Shan <[email protected]>
>> ---
>> include/linux/kvm_host.h | 44 +++++++++++++++++++++-------------------
>> 1 file changed, 23 insertions(+), 21 deletions(-)
>>
>> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
>> index ae7735b490b4..85b61a456f1c 100644
>> --- a/include/linux/kvm_host.h
>> +++ b/include/linux/kvm_host.h
>> @@ -199,27 +199,6 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
>> struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
>> gpa_t addr);
>>
>> -#ifdef CONFIG_KVM_ASYNC_PF
>> -struct kvm_async_pf {
>> - struct work_struct work;
>> - struct list_head link;
>> - struct list_head queue;
>> - struct kvm_vcpu *vcpu;
>> - struct mm_struct *mm;
>> - gpa_t cr2_or_gpa;
>> - unsigned long addr;
>> - struct kvm_arch_async_pf arch;
>> - bool wakeup_all;
>> - bool notpresent_injected;
>> -};
>> -
>> -void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
>> -void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
>> -bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
>> - unsigned long hva, struct kvm_arch_async_pf *arch);
>> -int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
>> -#endif
>> -
>> #ifdef KVM_ARCH_WANT_MMU_NOTIFIER
>> struct kvm_gfn_range {
>> struct kvm_memory_slot *slot;
>> @@ -346,6 +325,29 @@ struct kvm_vcpu {
>> struct kvm_dirty_ring dirty_ring;
>> };
>>
>> +#ifdef CONFIG_KVM_ASYNC_PF
>> +struct kvm_async_pf {
>> + struct work_struct work;
>> + struct list_head link;
>> + struct list_head queue;
>> + struct kvm_vcpu *vcpu;
>> + struct mm_struct *mm;
>> + gpa_t cr2_or_gpa;
>> + unsigned long addr;
>> + struct kvm_arch_async_pf arch;
>> + bool wakeup_all;
>> + bool notpresent_injected;
>> +};
>> +
>> +void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
>> +void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
>> +bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
>> + unsigned long hva, struct kvm_arch_async_pf *arch);
>> +int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
>> +#else
>> +static inline void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu) { }
> why is that stub needed on ARM64 and not on the other archs?
>

We use the following pattern, suggested by James Morse.

int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int r;
switch (ext) {
:
case KVM_CAP_ASYNC_PF:
case KVM_CAP_ASYNC_PF_INT:
r = IS_ENABLED(CONFIG_KVM_ASYNC_PF) ? 1 : 0;
break;
default:
r = 0;
}

return r;
}

Thanks,
Gavin

>> +#endif
>> +
>> /* must be called with irqs disabled */
>> static __always_inline void guest_enter_irqoff(void)
>> {
>>
>