Re: [PATCH v5 08/12] Inject asynchronous page fault into a guest if page is swapped out.

Avi Kivity
2010-08-24T12:33:59Z

On 08/24/2010 03:28 PM, Gleb Natapov wrote:
> On Mon, Aug 23, 2010 at 07:17:20PM +0300, Avi Kivity wrote:
>>> +static int apf_put_user(struct kvm_vcpu *vcpu, u32 val)
>>> +{
>>> + if (unlikely(vcpu->arch.apf_memslot_ver !=
>>> + vcpu->kvm->memslot_version)) {
>>> + u64 gpa = vcpu->arch.apf_msr_val& ~0x3f;
>>> + unsigned long addr;
>>> + int offset = offset_in_page(gpa);
>>> +
>>> + addr = gfn_to_hva(vcpu->kvm, gpa>> PAGE_SHIFT);
>>> + vcpu->arch.apf_data = (u32 __user *)(addr + offset);
>>> + if (kvm_is_error_hva(addr)) {
>>> + vcpu->arch.apf_data = NULL;
>>> + return -EFAULT;
>>> + }
>>> + }
>>> +
>>> + return put_user(val, vcpu->arch.apf_data);
>>> +}
>> This nice cache needs to be outside apf to reduce complexity for
>> reviewers and since it is useful for others.
>>
>> Would be good to have memslot-cached kvm_put_guest() and kvm_get_guest().
>>
> Something like this? (only compile tested)

Yes, exactly.

--
error compiling committee.c: too many arguments to function