Re: [PATCH 11/22] KVM: MMU: Add infrastructure for two-level page walker

Joerg Roedel
2010-04-28T10:52:01Z

On Tue, Apr 27, 2010 at 03:34:10PM +0300, Avi Kivity wrote:
> On 04/27/2010 01:38 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.
> >
> >+static inline gfn_t gpa_to_gfn(gpa_t gpa)
> >+{
> >+ return (gfn_t)gpa>> PAGE_SHIFT;
> >+}
> >+
>
> This overflows on 32-bit, since gpa_t is u64 and gfn_t is ulong.

Hm, this is a problem outside of this patchset too (for 32bit hosts).
The best solution is probably to convert gfn_t to u64 too.

Joerg