Re: [Qemu-devel] [PATCH v1 6/7] kvm/x86: Hyper-V SynIC message slot pending clearing at SINT ack

[Andrey Smetanin <asmetanin@virtuozzo.com>]

On 11/25/2015 07:52 PM, Paolo Bonzini wrote:
>
>
> On 25/11/2015 16:20, Andrey Smetanin wrote:
>> +static void synic_clear_sint_msg_pending(struct kvm_vcpu_hv_synic *synic,
>> +					u32 sint)
>> +{
>> +	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
>> +	struct page *page;
>> +	gpa_t gpa;
>> +	struct hv_message *msg;
>> +	struct hv_message_page *msg_page;
>> +
>> +	gpa = synic->msg_page & PAGE_MASK;
>> +	page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
>> +	if (is_error_page(page)) {
>> +		vcpu_err(vcpu, "Hyper-V SynIC can't get msg page, gpa 0x%llx\n",
>> +			 gpa);
>> +		return;
>> +	}
>> +	msg_page = kmap_atomic(page);
>
> But the message page is not being pinned, is it?
>
Actually I don't know anything about pinning.
Is it pinning against page swapping ?
Could you please clarify and provide an API to use in this case ?
> Paolo
>
>> +	msg = &msg_page->sint_message[sint];
>> +	msg->header.message_flags.msg_pending = 0;
>> +
>> +	kunmap_atomic(msg_page);
>> +	kvm_release_page_dirty(page);
>> +	kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
>> +}
>> +