Re: [PATCH 3/3] migration dirtybitmap support ARMv7

[Mario Smarduch <m.smarduch@samsung.com>]

Hi Eric, Mark -
   what repository should I use to pick up Eric patches?

For kvm_vm_ioctl_get_dirty_log() not sure what to make generic
it appears generic enough and it does what it needs to do?

Thanks,
  Mario

On 04/15/2014 02:06 AM, Marc Zyngier wrote:
> On 15/04/14 02:24, Mario Smarduch wrote:
>>
>> - support QEMU interface for initial VM Write Protect
>> - QEMU Dirty bit map log retrieval
>>
>>
>> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
>> ---
>>  arch/arm/kvm/arm.c |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 61 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
>> index bd18bb8..9076e3d 100644
>> --- a/arch/arm/kvm/arm.c
>> +++ b/arch/arm/kvm/arm.c
>> @@ -241,6 +241,8 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
>>  				   const struct kvm_memory_slot *old,
>>  				   enum kvm_mr_change change)
>>  {
>> +	if ((change != KVM_MR_DELETE) && (mem->flags & KVM_MEM_LOG_DIRTY_PAGES))
>> +		kvm_mmu_slot_remove_write_access(kvm, mem->slot);
>>  }
> 
> There is a patch by Eric Auger doing the same thing. Please use it as a
> dependency.
> 
>>  void kvm_arch_flush_shadow_all(struct kvm *kvm)
>> @@ -773,9 +775,67 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
>>  	}
>>  }
>>  
>> +/*
>> + * Walks the memslot dirty bitmap, write protects dirty pages for next rount,
>> + * and stores the dirty bitmap fo QEMU retrieval.
>> + *
>> + */
>>  int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
>>  {
>> -	return -EINVAL;
>> +	int r;
>> +	struct kvm_memory_slot *memslot;
>> +	unsigned long n, i;
>> +	unsigned long *dirty_bitmap;
>> +	unsigned long *dirty_bitmap_buffer;
>> +	bool is_dirty = false;
>> +	gfn_t offset;
>> +
>> +	mutex_lock(&kvm->slots_lock);
>> +	r = -EINVAL;
>> +
>> +	if (log->slot >= KVM_USER_MEM_SLOTS)
>> +		goto out;
>> +
>> +	memslot = id_to_memslot(kvm->memslots, log->slot);
>> +	dirty_bitmap = memslot->dirty_bitmap;
>> +
>> +	r = -ENOENT;
>> +	if (!dirty_bitmap)
>> +		goto out;
>> +
>> +	n = kvm_dirty_bitmap_bytes(memslot);
>> +	dirty_bitmap_buffer = dirty_bitmap + n / sizeof(long);
>> +	memset(dirty_bitmap_buffer, 0, n);
>> +
>> +	spin_lock(&kvm->mmu_lock);
>> +	for (i = 0; i < n / sizeof(long); i++) {
>> +		unsigned long mask;
>> +
>> +		if (!dirty_bitmap[i])
>> +			continue;
>> +
>> +		is_dirty = true;
>> +		offset = i * BITS_PER_LONG;
>> +		kvm_mmu_write_protect_pt_masked(kvm, memslot, offset,
>> +							dirty_bitmap[i]);
>> +		mask = dirty_bitmap[i];
>> +		dirty_bitmap_buffer[i] = mask;
>> +		dirty_bitmap[i] = 0;
>> +	}
>> +
>> +	if (is_dirty)
>> +		kvm_tlb_flush_vmid(kvm);
>> +
>> +	spin_unlock(&kvm->mmu_lock);
>> +	r = -EFAULT;
>> +
>> +	if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
>> +		goto out;
>> +
>> +	r = 0;
>> +out:
>> +	mutex_unlock(&kvm->slots_lock);
>> +	return r;
>>  }
> 
> This is a direct copy of the x86 code. Please make it generic.
> 
>>  static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
>>
> 
> Thanks,
> 
> 	M.
>