This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


RE: [Xen-devel] Re: xen dependant on pcpu 0 ?

To: Jan Beulich <JBeulich@xxxxxxxxxx>, Sander Eikelenboom <linux@xxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] Re: xen dependant on pcpu 0 ?
From: "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>
Date: Wed, 13 Oct 2010 23:00:21 +0800
Accept-language: en-US
Acceptlanguage: en-US
Cc: Ian <Ian.Campbell@xxxxxxxxxxxxx>, Jeremy Fitzhardinge <jeremy@xxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Keir Fraser <keir.fraser@xxxxxxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Delivery-date: Wed, 13 Oct 2010 08:03:06 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4CB5DDC9020000780001CE31@xxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <1452957126.20101012182813@xxxxxxxxxxxxxx> <20101012164433.GB21567@xxxxxxxxxxxx> <93878465.20101013153641@xxxxxxxxxxxxxx> <4CB5DDC9020000780001CE31@xxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Actq4rjVfCt9pH6kRx+8tYSe1dWGXQAA81xw
Thread-topic: [Xen-devel] Re: xen dependant on pcpu 0 ?

>-----Original Message-----
>From: Jan Beulich [mailto:JBeulich@xxxxxxxxxx]
>Sent: Wednesday, October 13, 2010 10:27 PM
>To: Sander Eikelenboom
>Cc: Ian; Keir Fraser; Jeremy Fitzhardinge; Jiang, Yunhong;
>xen-devel@xxxxxxxxxxxxxxxxxxx; Konrad Rzeszutek Wilk
>Subject: [Xen-devel] Re: xen dependant on pcpu 0 ?
>>>> On 13.10.10 at 15:36, Sander Eikelenboom <linux@xxxxxxxxxxxxxx> wrote:
>> it's this one:
>> WARN_ON(msi->table_base != read_pci_mem_bar(bus, slot, func, bir));
>Yeah, read_pci_mem_bar() uses an inverted mask in two places.
>Would you remove the ~ from the two uses of PCI_BASE_ADDRESS_MEM_MASK
>in that function and try again?
>(Yunhong, you had tested the patch that introduced this, and this
>warning would basically trigger unconditionally as it stands. Didn't
>you notice that in your logs?)

A bit amazing to me, but I do remember I didn't notice such log.
And seems with this bug, the patch itself should not work at all, since the 
PBA_addr is not correct, but I do remember with attached test module, and your 
patch, the write_vector() will cause fault.


>The main thing however, if I correctly remember the context of this
>thread, is that this code was only recently introduced and doesn't
>exist in the 4.0 tree, so your original problem is unlikely caused by it.
>> I have added some printk's .. and read_pci_mem_bar seems to return a bogus
>> value .. the pba_addr is used later in the function, but i can't oversee if
>> and when this could have implications.
>> This also occurs when disabling the pci_resource_align on the kernel line.
>> In the same function it seems to trigger
>>            if ( d )
>>             {
>>                 /* XXX How to deal with existing mappings? */
>>             }
>> Which seems to be a bit odd for a freshly booted system with no domU
>> restarts ?
>No, the comment refers to potentially existing mappings (which
>would need to be actively searched for). It doesn't mean there have
>to be any.

Attachment: ro_msi.c
Description: ro_msi.c

Xen-devel mailing list
<Prev in Thread] Current Thread [Next in Thread>