[PATCH v2 0/6] x86/kvm: add boot parameters for max vcpu configs

[PATCH v2 0/6] x86/kvm: add boot parameters for max vcpu configs

[Juergen Gross]

In order to be able to have a single kernel for supporting even huge
numbers of vcpus per guest some arrays should be sized dynamically.

The easiest way to do that is to add boot parameters for the maximum
number of vcpus and to calculate the maximum vcpu-id from that using
either the host topology or a topology hint via another boot parameter.

This patch series is doing that for x86. The same scheme can be easily
adapted to other architectures, but I don't want to do that in the
first iteration.

In the long term I'd suggest to have a per-guest setting of the two
parameters allowing to spare some memory for smaller guests. OTOH this
would require new ioctl()s and respective qemu modifications, so I let
those away for now.

I've tested the series not to break normal guest operation and the new
parameters to be effective on x86. For Arm64 I did a compile test only.

Changes in V2:
- removed old patch 1, as already applied
- patch 1 (old patch 2) only for reference, as the patch is already in
  the kvm tree
- switch patch 2 (old patch 3) to calculate vcpu-id
- added patch 4

Juergen Gross (6):
  x86/kvm: remove non-x86 stuff from arch/x86/kvm/ioapic.h
  x86/kvm: add boot parameter for adding vcpu-id bits
  x86/kvm: introduce per cpu vcpu masks
  kvm: use kvfree() in kvm_arch_free_vm()
  kvm: allocate vcpu pointer array separately
  x86/kvm: add boot parameter for setting max number of vcpus per guest

 .../admin-guide/kernel-parameters.txt         | 25 ++++++
 arch/arm64/include/asm/kvm_host.h             |  1 -
 arch/arm64/kvm/arm.c                          | 23 ++++--
 arch/x86/include/asm/kvm_host.h               | 26 +++++--
 arch/x86/kvm/hyperv.c                         | 25 ++++--
 arch/x86/kvm/ioapic.c                         | 12 ++-
 arch/x86/kvm/ioapic.h                         |  8 +-
 arch/x86/kvm/irq_comm.c                       |  9 ++-
 arch/x86/kvm/x86.c                            | 78 ++++++++++++++++++-
 include/linux/kvm_host.h                      | 26 ++++++-
 10 files changed, 198 insertions(+), 35 deletions(-)

-- 
2.26.2

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v2 4/6] kvm: use kvfree() in kvm_arch_free_vm()

[Juergen Gross]

By switching from kfree() to kvfree() in kvm_arch_free_vm() Arm64 can
use the common variant. This can be accomplished by adding another
macro __KVM_HAVE_ARCH_VM_FREE, which will be used only by x86 for now.

Further simplification can be achieved by adding __kvm_arch_free_vm()
doing the common part.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
V2:
- new patch
---
 arch/arm64/include/asm/kvm_host.h | 1 -
 arch/arm64/kvm/arm.c              | 8 --------
 arch/x86/include/asm/kvm_host.h   | 2 ++
 arch/x86/kvm/x86.c                | 2 +-
 include/linux/kvm_host.h          | 9 ++++++++-
 5 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 41911585ae0c..39601fb87e69 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -767,7 +767,6 @@ int kvm_set_ipa_limit(void);
 
 #define __KVM_HAVE_ARCH_VM_ALLOC
 struct kvm *kvm_arch_alloc_vm(void);
-void kvm_arch_free_vm(struct kvm *kvm);
 
 int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type);
 
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 0ca72f5cda41..38fff5963d9f 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -299,14 +299,6 @@ struct kvm *kvm_arch_alloc_vm(void)
 	return vzalloc(sizeof(struct kvm));
 }
 
-void kvm_arch_free_vm(struct kvm *kvm)
-{
-	if (!has_vhe())
-		kfree(kvm);
-	else
-		vfree(kvm);
-}
-
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 {
 	if (irqchip_in_kernel(kvm) && vgic_initialized(kvm))
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a809a9e4fa5c..f16fadfc030a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1521,6 +1521,8 @@ static inline struct kvm *kvm_arch_alloc_vm(void)
 {
 	return __vmalloc(kvm_x86_ops.vm_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
 }
+
+#define __KVM_HAVE_ARCH_VM_FREE
 void kvm_arch_free_vm(struct kvm *kvm);
 
 #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fd19b72a5733..cc552763f0e4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11129,7 +11129,7 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
 void kvm_arch_free_vm(struct kvm *kvm)
 {
 	kfree(to_kvm_hv(kvm)->hv_pa_pg);
-	vfree(kvm);
+	__kvm_arch_free_vm(kvm);
 }
 
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ae7735b490b4..d75e9c2a00b1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1044,10 +1044,17 @@ static inline struct kvm *kvm_arch_alloc_vm(void)
 {
 	return kzalloc(sizeof(struct kvm), GFP_KERNEL);
 }
+#endif
+
+static inline void __kvm_arch_free_vm(struct kvm *kvm)
+{
+	kvfree(kvm);
+}
 
+#ifndef __KVM_HAVE_ARCH_VM_FREE
 static inline void kvm_arch_free_vm(struct kvm *kvm)
 {
-	kfree(kvm);
+	__kvm_arch_free_vm(kvm);
 }
 #endif
 
-- 
2.26.2

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v2 5/6] kvm: allocate vcpu pointer array separately

[Juergen Gross]

Prepare support of very large vcpu numbers per guest by moving the
vcpu pointer array out of struct kvm.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V2:
- rebase to new kvm_arch_free_vm() implementation
---
 arch/arm64/kvm/arm.c            | 21 +++++++++++++++++++--
 arch/x86/include/asm/kvm_host.h |  5 +----
 arch/x86/kvm/x86.c              | 18 ++++++++++++++++++
 include/linux/kvm_host.h        | 17 +++++++++++++++--
 4 files changed, 53 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 38fff5963d9f..8bb5caeba007 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -293,10 +293,27 @@ long kvm_arch_dev_ioctl(struct file *filp,
 
 struct kvm *kvm_arch_alloc_vm(void)
 {
+	struct kvm *kvm;
+
+	if (!has_vhe())
+		kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
+	else
+		kvm = vzalloc(sizeof(struct kvm));
+
+	if (!kvm)
+		return NULL;
+
 	if (!has_vhe())
-		return kzalloc(sizeof(struct kvm), GFP_KERNEL);
+		kvm->vcpus = kcalloc(KVM_MAX_VCPUS, sizeof(void *), GFP_KERNEL);
+	else
+		kvm->vcpus = vzalloc(KVM_MAX_VCPUS * sizeof(void *));
+
+	if (!kvm->vcpus) {
+		kvm_arch_free_vm(kvm);
+		kvm = NULL;
+	}
 
-	return vzalloc(sizeof(struct kvm));
+	return kvm;
 }
 
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f16fadfc030a..6c28d0800208 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1517,10 +1517,7 @@ static inline void kvm_ops_static_call_update(void)
 }
 
 #define __KVM_HAVE_ARCH_VM_ALLOC
-static inline struct kvm *kvm_arch_alloc_vm(void)
-{
-	return __vmalloc(kvm_x86_ops.vm_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
-}
+struct kvm *kvm_arch_alloc_vm(void);
 
 #define __KVM_HAVE_ARCH_VM_FREE
 void kvm_arch_free_vm(struct kvm *kvm);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cc552763f0e4..ff142b6dd00c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11126,6 +11126,24 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
 	static_call(kvm_x86_sched_in)(vcpu, cpu);
 }
 
+struct kvm *kvm_arch_alloc_vm(void)
+{
+	struct kvm *kvm;
+
+	kvm = __vmalloc(kvm_x86_ops.vm_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+	if (!kvm)
+		return NULL;
+
+	kvm->vcpus = __vmalloc(KVM_MAX_VCPUS * sizeof(void *),
+			       GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+	if (!kvm->vcpus) {
+		vfree(kvm);
+		kvm = NULL;
+	}
+
+	return kvm;
+}
+
 void kvm_arch_free_vm(struct kvm *kvm)
 {
 	kfree(to_kvm_hv(kvm)->hv_pa_pg);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d75e9c2a00b1..9e2a5f1c6f54 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -536,7 +536,7 @@ struct kvm {
 	struct mutex slots_arch_lock;
 	struct mm_struct *mm; /* userspace tied to this vm */
 	struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
-	struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
+	struct kvm_vcpu **vcpus;
 
 	/*
 	 * created_vcpus is protected by kvm->lock, and is incremented
@@ -1042,12 +1042,25 @@ void kvm_arch_pre_destroy_vm(struct kvm *kvm);
  */
 static inline struct kvm *kvm_arch_alloc_vm(void)
 {
-	return kzalloc(sizeof(struct kvm), GFP_KERNEL);
+	struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
+
+	if (!kvm)
+		return NULL;
+
+	kvm->vcpus = kcalloc(KVM_MAX_VCPUS, sizeof(void *), GFP_KERNEL);
+	if (!kvm->vcpus) {
+		kfree(kvm);
+		kvm = NULL;
+	}
+
+	return kvm;
 }
 #endif
 
 static inline void __kvm_arch_free_vm(struct kvm *kvm)
 {
+	if (kvm)
+		kvfree(kvm->vcpus);
 	kvfree(kvm);
 }
 
-- 
2.26.2

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH v2 5/6] kvm: allocate vcpu pointer array separately

[Marc Zyngier]

On Fri, 03 Sep 2021 14:08:06 +0100,
Juergen Gross <jgross@suse.com> wrote:
> 
> Prepare support of very large vcpu numbers per guest by moving the
> vcpu pointer array out of struct kvm.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
> V2:
> - rebase to new kvm_arch_free_vm() implementation
> ---
>  arch/arm64/kvm/arm.c            | 21 +++++++++++++++++++--
>  arch/x86/include/asm/kvm_host.h |  5 +----
>  arch/x86/kvm/x86.c              | 18 ++++++++++++++++++
>  include/linux/kvm_host.h        | 17 +++++++++++++++--
>  4 files changed, 53 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 38fff5963d9f..8bb5caeba007 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -293,10 +293,27 @@ long kvm_arch_dev_ioctl(struct file *filp,
>  
>  struct kvm *kvm_arch_alloc_vm(void)
>  {
> +	struct kvm *kvm;
> +
> +	if (!has_vhe())
> +		kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
> +	else
> +		kvm = vzalloc(sizeof(struct kvm));
> +
> +	if (!kvm)
> +		return NULL;
> +
>  	if (!has_vhe())
> -		return kzalloc(sizeof(struct kvm), GFP_KERNEL);
> +		kvm->vcpus = kcalloc(KVM_MAX_VCPUS, sizeof(void *), GFP_KERNEL);
> +	else
> +		kvm->vcpus = vzalloc(KVM_MAX_VCPUS * sizeof(void *));
> +
> +	if (!kvm->vcpus) {
> +		kvm_arch_free_vm(kvm);
> +		kvm = NULL;
> +	}
>  
> -	return vzalloc(sizeof(struct kvm));
> +	return kvm;
>  }
>  
>  int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index f16fadfc030a..6c28d0800208 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1517,10 +1517,7 @@ static inline void kvm_ops_static_call_update(void)
>  }
>  
>  #define __KVM_HAVE_ARCH_VM_ALLOC
> -static inline struct kvm *kvm_arch_alloc_vm(void)
> -{
> -	return __vmalloc(kvm_x86_ops.vm_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
> -}
> +struct kvm *kvm_arch_alloc_vm(void);
>  
>  #define __KVM_HAVE_ARCH_VM_FREE
>  void kvm_arch_free_vm(struct kvm *kvm);
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index cc552763f0e4..ff142b6dd00c 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -11126,6 +11126,24 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
>  	static_call(kvm_x86_sched_in)(vcpu, cpu);
>  }
>  
> +struct kvm *kvm_arch_alloc_vm(void)
> +{
> +	struct kvm *kvm;
> +
> +	kvm = __vmalloc(kvm_x86_ops.vm_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
> +	if (!kvm)
> +		return NULL;
> +
> +	kvm->vcpus = __vmalloc(KVM_MAX_VCPUS * sizeof(void *),
> +			       GFP_KERNEL_ACCOUNT | __GFP_ZERO);
> +	if (!kvm->vcpus) {
> +		vfree(kvm);
> +		kvm = NULL;
> +	}
> +
> +	return kvm;
> +}
> +
>  void kvm_arch_free_vm(struct kvm *kvm)
>  {
>  	kfree(to_kvm_hv(kvm)->hv_pa_pg);
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index d75e9c2a00b1..9e2a5f1c6f54 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -536,7 +536,7 @@ struct kvm {
>  	struct mutex slots_arch_lock;
>  	struct mm_struct *mm; /* userspace tied to this vm */
>  	struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
> -	struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
> +	struct kvm_vcpu **vcpus;

At this stage, I really wonder why we are not using an xarray instead.

I wrote this [1] a while ago, and nothing caught fire. It was also a
net deletion of code...

	M.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=kvm-arm64/vcpu-xarray

-- 
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH v2 5/6] kvm: allocate vcpu pointer array separately

[Juergen Gross]

[-- Attachment #1.1.1.1: Type: text/plain, Size: 3827 bytes --]

On 03.09.21 16:41, Marc Zyngier wrote:
> On Fri, 03 Sep 2021 14:08:06 +0100,
> Juergen Gross <jgross@suse.com> wrote:
>>
>> Prepare support of very large vcpu numbers per guest by moving the
>> vcpu pointer array out of struct kvm.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>> V2:
>> - rebase to new kvm_arch_free_vm() implementation
>> ---
>>   arch/arm64/kvm/arm.c            | 21 +++++++++++++++++++--
>>   arch/x86/include/asm/kvm_host.h |  5 +----
>>   arch/x86/kvm/x86.c              | 18 ++++++++++++++++++
>>   include/linux/kvm_host.h        | 17 +++++++++++++++--
>>   4 files changed, 53 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
>> index 38fff5963d9f..8bb5caeba007 100644
>> --- a/arch/arm64/kvm/arm.c
>> +++ b/arch/arm64/kvm/arm.c
>> @@ -293,10 +293,27 @@ long kvm_arch_dev_ioctl(struct file *filp,
>>   
>>   struct kvm *kvm_arch_alloc_vm(void)
>>   {
>> +	struct kvm *kvm;
>> +
>> +	if (!has_vhe())
>> +		kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
>> +	else
>> +		kvm = vzalloc(sizeof(struct kvm));
>> +
>> +	if (!kvm)
>> +		return NULL;
>> +
>>   	if (!has_vhe())
>> -		return kzalloc(sizeof(struct kvm), GFP_KERNEL);
>> +		kvm->vcpus = kcalloc(KVM_MAX_VCPUS, sizeof(void *), GFP_KERNEL);
>> +	else
>> +		kvm->vcpus = vzalloc(KVM_MAX_VCPUS * sizeof(void *));
>> +
>> +	if (!kvm->vcpus) {
>> +		kvm_arch_free_vm(kvm);
>> +		kvm = NULL;
>> +	}
>>   
>> -	return vzalloc(sizeof(struct kvm));
>> +	return kvm;
>>   }
>>   
>>   int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
>> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
>> index f16fadfc030a..6c28d0800208 100644
>> --- a/arch/x86/include/asm/kvm_host.h
>> +++ b/arch/x86/include/asm/kvm_host.h
>> @@ -1517,10 +1517,7 @@ static inline void kvm_ops_static_call_update(void)
>>   }
>>   
>>   #define __KVM_HAVE_ARCH_VM_ALLOC
>> -static inline struct kvm *kvm_arch_alloc_vm(void)
>> -{
>> -	return __vmalloc(kvm_x86_ops.vm_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
>> -}
>> +struct kvm *kvm_arch_alloc_vm(void);
>>   
>>   #define __KVM_HAVE_ARCH_VM_FREE
>>   void kvm_arch_free_vm(struct kvm *kvm);
>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>> index cc552763f0e4..ff142b6dd00c 100644
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -11126,6 +11126,24 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
>>   	static_call(kvm_x86_sched_in)(vcpu, cpu);
>>   }
>>   
>> +struct kvm *kvm_arch_alloc_vm(void)
>> +{
>> +	struct kvm *kvm;
>> +
>> +	kvm = __vmalloc(kvm_x86_ops.vm_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
>> +	if (!kvm)
>> +		return NULL;
>> +
>> +	kvm->vcpus = __vmalloc(KVM_MAX_VCPUS * sizeof(void *),
>> +			       GFP_KERNEL_ACCOUNT | __GFP_ZERO);
>> +	if (!kvm->vcpus) {
>> +		vfree(kvm);
>> +		kvm = NULL;
>> +	}
>> +
>> +	return kvm;
>> +}
>> +
>>   void kvm_arch_free_vm(struct kvm *kvm)
>>   {
>>   	kfree(to_kvm_hv(kvm)->hv_pa_pg);
>> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
>> index d75e9c2a00b1..9e2a5f1c6f54 100644
>> --- a/include/linux/kvm_host.h
>> +++ b/include/linux/kvm_host.h
>> @@ -536,7 +536,7 @@ struct kvm {
>>   	struct mutex slots_arch_lock;
>>   	struct mm_struct *mm; /* userspace tied to this vm */
>>   	struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
>> -	struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
>> +	struct kvm_vcpu **vcpus;
> 
> At this stage, I really wonder why we are not using an xarray instead.
> 
> I wrote this [1] a while ago, and nothing caught fire. It was also a
> net deletion of code...

Indeed, I'd prefer that solution!

Are you fine with me swapping my patch with yours in the series?


Juergen


[-- Attachment #1.1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 3135 bytes --]

[-- Attachment #1.2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 495 bytes --]

[-- Attachment #2: Type: text/plain, Size: 151 bytes --]

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH v2 5/6] kvm: allocate vcpu pointer array separately

[Marc Zyngier]

On Mon, 06 Sep 2021 05:33:35 +0100,
Juergen Gross <jgross@suse.com> wrote:
> 
> On 03.09.21 16:41, Marc Zyngier wrote:
>
> > At this stage, I really wonder why we are not using an xarray instead.
> > 
> > I wrote this [1] a while ago, and nothing caught fire. It was also a
> > net deletion of code...
> 
> Indeed, I'd prefer that solution!
> 
> Are you fine with me swapping my patch with yours in the series?

Of course, feel free to grab the whole series. You'll probably need
the initial patches to set the scene for this. On their own, they are
a nice cleanup, and I trust you can write a decent commit message for
the three patches affecting mips/s390/x86.

I would normally do that myself, but my network connectivity is
reduced to almost nothing at the moment.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH v2 5/6] kvm: allocate vcpu pointer array separately

[Sean Christopherson]

On Mon, Sep 06, 2021, Marc Zyngier wrote:
> On Mon, 06 Sep 2021 05:33:35 +0100,
> Juergen Gross <jgross@suse.com> wrote:
> > 
> > On 03.09.21 16:41, Marc Zyngier wrote:
> >
> > > At this stage, I really wonder why we are not using an xarray instead.
> > > 
> > > I wrote this [1] a while ago, and nothing caught fire. It was also a
> > > net deletion of code...
> > 
> > Indeed, I'd prefer that solution!
> > 
> > Are you fine with me swapping my patch with yours in the series?
> 
> Of course, feel free to grab the whole series. You'll probably need
> the initial patches to set the scene for this. On their own, they are
> a nice cleanup, and I trust you can write a decent commit message for
> the three patches affecting mips/s390/x86.

It would also be a good idea to convert kvm_for_each_vcpu() to use xa_for_each(),
I assume that's more performant than 2x atomic_read() + xa_load().  Unless I'm
misreading the code, xa_for_each() is guaranteed to iterate in ascending index
order, i.e. preserves the current vcpu0..vcpuN iteration order.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH v2 4/6] kvm: use kvfree() in kvm_arch_free_vm()

[Paolo Bonzini]

On 03/09/21 15:08, Juergen Gross wrote:
> By switching from kfree() to kvfree() in kvm_arch_free_vm() Arm64 can
> use the common variant. This can be accomplished by adding another
> macro __KVM_HAVE_ARCH_VM_FREE, which will be used only by x86 for now.
> 
> Further simplification can be achieved by adding __kvm_arch_free_vm()
> doing the common part.
> 
> Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Juergen Gross <jgross@suse.com>

Queued this one already, thanks.

Paolo

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm