Re: [PATCH v2 04/22] KVM: x86: introduce vcpu_gva_to_gpa to cleanup the code

Avi Kivity
2011-06-29T11:09:52Z

On 06/29/2011 01:56 PM, Xiao Guangrong wrote:
> On 06/29/2011 04:24 PM, Avi Kivity wrote:
>
> >> +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
> >> + gpa_t *gpa, struct x86_exception *exception,
> >> + bool write)
> >> +{
> >> + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
> >> +
> >> + if (write)
> >> + access |= PFERR_WRITE_MASK;
> >
> > Needs fetch as well so NX/SMEP can work.
> >
>
> This function is only used by read/write emulator, execute permission is
> not needed for read/write, no?

It's not good to have a function which only implements the functionality
partially. It can later be misused.

You can pass the page-fault-error-code instead of the write parameter, I
think it will be simpler.

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