Messages in this thread | | | Date | Wed, 8 Sep 2010 11:20:14 +0200 | From | "Roedel, Joerg" <> | Subject | Re: [PATCH 10/27] KVM: MMU: Add infrastructure for two-level page walker |
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On Mon, Sep 06, 2010 at 02:05:35PM -0400, Avi Kivity wrote: > On 09/06/2010 06:55 PM, Joerg Roedel wrote: > > This patch introduces a mmu-callback to translate gpa > > addresses in the walk_addr code. This is later used to > > translate l2_gpa addresses into l1_gpa addresses. > > > @@ -534,6 +534,11 @@ static inline gpa_t gfn_to_gpa(gfn_t gfn) > > return (gpa_t)gfn<< PAGE_SHIFT; > > } > > > > +static inline gfn_t gpa_to_gfn(gpa_t gpa) > > +{ > > + return (gfn_t)gpa>> PAGE_SHIFT; > > +} > > + > > That's a bug - gfn_t may be smaller than gpa_t, so you're truncating > just before the shift. Note the casts in the surrounding functions are > widening, not narrowing. > > However, gfn_t is u64 so the bug is only theoretical.
Will fix that in v4 too. Thanks.
Joerg
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