Re: [PATCH 3/8] kvm: Detect guest-memfd flags supported

[Peter Xu <peterx@redhat.com>]

On Thu, Nov 13, 2025 at 04:15:50PM -0500, Peter Xu wrote:
> On Fri, Oct 24, 2025 at 11:52:01AM +0800, Xiaoyao Li wrote:
> > > @@ -2781,6 +2782,11 @@ static int kvm_init(AccelState *as, MachineState *ms)
> > >       kvm_supported_memory_attributes = kvm_vm_check_extension(s, KVM_CAP_MEMORY_ATTRIBUTES);
> > >       kvm_guest_memfd_supported = kvm_vm_check_extension(s, KVM_CAP_GUEST_MEMFD) &&
> > >           kvm_vm_check_extension(s, KVM_CAP_USER_MEMORY2);
> > > +    ret = kvm_vm_check_extension(s, KVM_CAP_GUEST_MEMFD_FLAGS);
> > > +    if (ret > 0)
> > > +        kvm_guest_memfd_flags_supported = (uint64_t)ret;
> > > +    else
> > > +        kvm_guest_memfd_flags_supported = 0;
> > 
> > Nit:
> > 1. QEMU's coding style always requires curly braces.
> > 2. is the (uint64_t) necessary?
> > 3. can we name it "kvm_supported_guest_memfd_flags" to make it consistent
> > with "kvm_supported_memory_attributes"?
> > 
> > so how about
> > 
> > kvm_supported_guest_memfd_flags = kvm_vm_check_extension(s,
> > KVM_CAP_GUEST_MEMFD_FLAGS);
> >     if (kvm_supported_guest_memfd_flags < 0) {
> >         kvm_supported_guest_memfd_flags = 0;
> >     }
> 
> Yep this looks good, I'll use it, thanks.

About naming: note that we already have different styles (both below
variables introduced by your previous commits):

static uint64_t kvm_supported_memory_attributes;
static bool kvm_guest_memfd_supported;

I personally preferred kvm_guest_memfd* as prefix, so I kept it.

-- 
Peter Xu