From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Mueller Subject: Re: XSA-36 / howto fix broken IVRS ACPI table Date: Wed, 24 Apr 2013 22:03:54 +0200 Message-ID: <2822407.UaCHNbxBlk@sheik-lin> References: <123945469.jCKz4Rdygs@sheik-lin> <5856144.PyRpna87yD@sheik-lin> <51779C1D02000078000D0348@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51779C1D02000078000D0348@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Wednesday, 24. April 2013 07:47:25 Jan Beulich wrote: > >>> On 23.04.13 at 19:11, Hans Mueller wrote: > > However the problem seems not really to be fixed: > > Interrupts generated within one domain can still harm other domains which > > at least causes the kernel within these other domains to disable > > interrupts. > "The problem" being which problem? Even after looking back through > the list archives, I haven't been able to spot a corresponding problem > description. And if you resume a thread after several weeks without > sufficiently quoting the original, it would be rather desirable for you > to at least briefly summarize your original problem. Perhaps it was unclear - better than 'the' problem might be 'a' problem - as briefly described regarding interrupts becoming disabled across domain borders. However, I don't want to address that problem in this thread in detail, I just worry that the fixes applied to the BIOS are insufficient and want to check this before starting a perhaps unnecessary discussion about the 'interrupt problem'. Since XSA-36 Xen disabled the I/O virtualisation because there was a conflicting IOAPIC entry within the IVRS table (probably for the disabled northbridge IOAPIC & using the handle/id for the enabled southbridge IOAPIC). The manufacturer just removed this entry from the IVRS table which causes Xen to no longer complain about conflicting IOAPIC entries and enabling per-device vector maps. So currently only the southbridge IOAPIC is enabled. The question is whether the missing/disabled northbridge IOAPIC is a valid setup or might/will it raise any problems. > The same physical IRQ being shared by multiple devices is entirely > independent of XSA-36, and if your Dom0/DomU kernels can't cope > with that they are what need fixing. Is it obvious that such problems are not caused by the missing northbridge IOAPIC? I would then provide related details in a new thread. Best Regards Hans