Re: [PATCH v12 08/20] KVM: pfncache: allow a cache to be activated with a fixed (userspace) HVA

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 2024-02-06 at 20:03 -0800, Sean Christopherson wrote:
> +s390 folks (question on kvm_is_error_gpa() for ya)
> 
> On Mon, Jan 15, 2024, Paul Durrant wrote:
> > @@ -1398,7 +1414,9 @@ void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc);
> >   static inline void kvm_gpc_mark_dirty(struct gfn_to_pfn_cache *gpc)
> >   {
> >         lockdep_assert_held(&gpc->lock);
> > -       mark_page_dirty_in_slot(gpc->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT);
> > +
> > +       if (gpc->gpa != KVM_XEN_INVALID_GPA)
> 
> KVM_XEN_INVALID_GPA absolutely doesn't belong in common code.  Not to mention
> that it will break when Paolo (rightly) moves it to an x86 header.
> 
> https://lore.kernel.org/all/20240131233056.10845-3-pbonzini@xxxxxxxxxx

We can use plain INVALID_GPA for that, I think. ISTR the reason we have
a separate KVM_XEN_INVALID_GPA is because that's a userspace API.

...

> But!  kvm_is_error_gpa() already exists, and it very, very sneakily
> does a memslot lookup and checks for a valid HVA.

Hm, that doesn't sound as fast as simple comparison. We also can't do
it from kvm_gpc_check(), can we?

Attachment: smime.p7s
Description: S/MIME cryptographic signature


[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux