[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: IOMMU faults after S3
- To: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
- Date: Fri, 27 Mar 2026 12:23:18 +0000
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=dsZnhq0sZwcOoKP17KmNt95ytMCuW07FZhhsS//8P9Y=; b=IRMpWaH4aYpsl1ebpwAjTRs161TLa8RYQ7sXDrBUzieq4rIcEHqMYmL4JBZKoDXbJI86+Ydty+9M/O+PXYKF3r1TOR6AsSXJI3oq4mZDGetVGNT/twszlaqvaHcLpNSEzxwmXw0AbBEam/BdihKz4e1KD/Sfe9W3YsSrPE7DyzLQja/WEfl1HYwEO8RXK/xrwnh3ZqCj3ljYgzcYDxs+8U2UowJKGtD0o3H5qH9iqt8Pke45Tfo173D4P55r5MQJwA31YZgpeInYRa+faq9MStCmIYrg2Jrm9e35o5XXCVQKMcqNsywAmlWaDcQ34VlHYFdv9utC19yrabaxXyuxpQ==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=lDcxe0yhvHeM6sJJYBtYMhqQhHerZ60EJ9dTjZ3VOcEMnoB7WdmMW+4JyGJfF887auxxyquG/fyno6Iy+tzuIwbk+FrFPvTC7C6eKYl3bbpFb9jYaCIuERffbJ7K0gMPLRcGK5wyWNPIa3sBEIPGiF9+L+uedTW67sPY5SmS8L4KusO/AxSsiDiJFNikwHOsxaPYepQ/TxTwWF9cs7z+WIIVfszA7Vb6nuBngeUeOYFemr0j9muY+5HkS5xYwiXrQEoNlQ69UJJfrgYM8aJgtQ3F0lPyQu1ylQGqNKxHjJrc0dnBvVHWbKcR/fo2sZnfyTkP3rKw7UrsKm5zijnjAQ==
- Authentication-results: eu.smtp.expurgate.cloud; dkim=pass header.s=selector1 header.d=citrix.com header.i="@citrix.com" header.h="From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck"
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com;
- Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>
- Delivery-date: Fri, 27 Mar 2026 12:23:37 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 27/03/2026 10:19 am, Marek Marczykowski-Górecki wrote:
> Hi,
>
> I noticed that on some systems, there are a lot of IOMMU faults after
> S3. I can see it also on a laptop with MTL, but it affects also the ADL
> gitlab runner:
>
> https://gitlab.com/xen-project/hardware/xen/-/jobs/13661033722
> (XEN) [ 37.201160] [VT-D]DMAR:[DMA Write] Request device [0000:00:1e.6]
> fault addr 0
> (XEN) [ 37.201164] [VT-D]DMAR: reason 02 - Present bit in context entry
> is clear
> (XEN) [ 37.202332] [VT-D]DMAR:[DMA Write] Request device [0000:00:1e.6]
> fault addr 0
> (XEN) [ 37.202339] [VT-D]DMAR: reason 02 - Present bit in context entry
> is clear
>
> Interestingly, the 0000:00:1e.6 device is not even listed by lspci.
Ah. HPETs and IO-APICs get assigned an otherwise unused PCI address for
the purposes of interrupt remapping.
acpi$ grep -A7 HPET dmar.dsl
[060h 0096 1] Device Scope Type : 04 [Message-capable HPET Device]
[061h 0097 1] Entry Length : 08
[062h 0098 2] Reserved : 0000
[064h 0100 1] Enumeration ID : 00
[065h 0101 1] PCI Bus Number : 00
[066h 0102 2] PCI Path : 1E,06
This is information carried in the DMAR / IVRS ACPI tables, and it seems
to be the same on a random Intel system of mine.
~Andrew
|
