From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: Bug#599089: linux-image-2.6.32-5-xen-686: Kernel
 Panics when using NFS from DomU to Dom0
Date: Tue, 05 Oct 2010 09:54:34 -0700
Message-ID: <4CAB584A.7090909@goop.org>
References: <4CA9EF03.20407@gmail.com>	
	<1286272060.23155.7508.camel@zakaz.uk.xensource.com>
	<1286272348.23155.7527.camel@zakaz.uk.xensource.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xensource.com>
In-Reply-To: <1286272348.23155.7527.camel@zakaz.uk.xensource.com>
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: Ian Campbell <ijc@hellion.org.uk>
Cc: 599089@bugs.debian.org, xen-devel <xen-devel@lists.xensource.com>, Arnd Hannemann <hannemann@nets.rwth-aachen.de>, Jason Kendall <jakendall@gmail.com>
List-Id: xen-devel@lists.xenproject.org

 On 10/05/2010 02:52 AM, Ian Campbell wrote:
> On Tue, 2010-10-05 at 10:47 +0100, Ian Campbell wrote:
>> In addition to the kernel logging of the error I get this from the
>> hypervisor:
>> (XEN) mm.c:2062:d0 Error pfn 16d99: rd=ffff83011fefa000,
>> od=0000000000000000, caf=180000000000000, taf=0000000000000000
>> (XEN) mm.c:658:d0 Could not get page ref for pfn 16d99
>> (XEN) mm.c:3621:d0 Could not get page for mach->phys update
> Adding a bit more logging to the kernel I get:
> gnttb_copy_grant_page old c22ebcd8 P:0x1ec8e M:0xc499d F:0x41000000
> gnttb_copy_grant_page new c2324ce0 P:0x1fe18 M:0x11cd32 F:0x40000000
> (XEN) mm.c:2062:d0 Error pfn 1cd32: rd=ffff83011fefa000, od=0000000000000000, caf=180000000000000, taf=0000000000000000
> (XEN) mm.c:658:d0 Could not get page ref for pfn 1cd32
> (XEN) mm.c:3621:d0 Could not get page for mach->phys update
>
> Notice how MFN 0x11cd32 has become 0x1cd32 by the time it gets to the
> hypervisor!

Oy, more of these.  It might be better to use PFN_PHYS().

    J

> The following fixes it for me.
>
> From: Ian Campbell <ian.campbell@citrix.com>
> Subject: xen: grant table: do not truncate machine address on gnttab_copy_grant_page
>
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
>
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -578,7 +578,7 @@ int gnttab_copy_grant_page(grant_ref_t ref, struct page **pagep)
>  	if (!xen_feature(XENFEAT_auto_translated_physmap)) {
>  		set_phys_to_machine(page_to_pfn(new_page), INVALID_P2M_ENTRY);
>  
> -		mmu.ptr = (new_mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
> +		mmu.ptr = ((u64)new_mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
>  		mmu.val = pfn;
>  		err = HYPERVISOR_mmu_update(&mmu, 1, NULL, DOMID_SELF);
>  		BUG_ON(err);
>