Re: [Xen-devel] Re: xen crash in tmem: checking a xen pfn for domain ownership

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

On 21/09/2010 00:03, "Dan Magenheimer" <dan.magenheimer@xxxxxxxxxx> wrote:

>     if ( is_hvm_domain(current->domain) )
>     {
>         xmfn = mfn_x(gfn_to_mfn_unshare(current->domain, cmfn, &t, 2));
>         if (t != p2m_ram_rw || xmfn == INVALID_MFN)
>             return NULL;
>     }
>     else
>     {
>         xmfn = cmfn;
>         if (!mfn_valid(xmfn))
>             return NULL;
>     }

This is needlessly cumbersome. You can do it without the if(is_hvm):

    xmfn = mfn_x(gfn_to_mfn(current->domain, cmfn, &t);
    if ((t != p2m_ram_rw) || !mfn_valid(xmfn))
        return NULL;

(Didn't use hfn_to_mfn_unshare as you have decided against it.)

Rest of the code looks fine.

 -- Keir



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