Re: [Xen-devel] [PATCH REPOST] pv-grub: Fix for incorrect dom->p2m_host[] list initialization

[Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>]

Hello,

Daniel Kiper, le Fri 22 Apr 2011 23:25:45 +0200, a écrit :
> If pfn of newly allocated page is less than currently requested pfn
> then relevant earlier allocated mfn is overwritten which leads to
> domain crash later.

Oops, good catch! And unfortunately it happens seldomly... I guess it
may be the culprit for a fair number of other issues.

> +     if (new_pfn < i)
> +             for (new_pfn = i; new_pfn < dom->total_pages; ++new_pfn)
> +                     if (dom->p2m_host[new_pfn] == new_mfn)
> +                             break;

Instead of looking for the page, which takes a linear time for each page
and thus potentially quadratic time, we should probably rather record
which PFN the MFNs < allocated have been moved to?

Samuel

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