From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 6442F4617B; Mon, 3 Feb 2025 04:39:22 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 2D2234060F; Mon, 3 Feb 2025 04:39:22 +0100 (CET) Received: from inbox.dpdk.org (inbox.dpdk.org [95.142.172.178]) by mails.dpdk.org (Postfix) with ESMTP id 9CD6A400EF for ; Mon, 3 Feb 2025 04:39:20 +0100 (CET) Received: by inbox.dpdk.org (Postfix, from userid 33) id 8800F4617C; Mon, 3 Feb 2025 04:39:20 +0100 (CET) From: bugzilla@dpdk.org To: dev@dpdk.org Subject: [DPDK/vhost/virtio Bug 1642] Devices bound to igb_uio with VT-d enabled do not work on Linux kernel 3.15-3.17 Date: Mon, 03 Feb 2025 03:39:20 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: DPDK X-Bugzilla-Component: vhost/virtio X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: nandinipersad361@gmail.com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: Normal X-Bugzilla-Assigned-To: dev@dpdk.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: multipart/alternative; boundary=17385539600.4C7d1dEa.2139567 Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://bugs.dpdk.org/ Auto-Submitted: auto-generated X-Auto-Response-Suppress: All MIME-Version: 1.0 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org --17385539600.4C7d1dEa.2139567 Date: Mon, 3 Feb 2025 04:39:20 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://bugs.dpdk.org/ Auto-Submitted: auto-generated X-Auto-Response-Suppress: All https://bugs.dpdk.org/show_bug.cgi?id=3D1642 Bug ID: 1642 Summary: Devices bound to igb_uio with VT-d enabled do not work on Linux kernel 3.15-3.17 Product: DPDK Version: unspecified Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: Normal Component: vhost/virtio Assignee: dev@dpdk.org Reporter: nandinipersad361@gmail.com Target Milestone: --- When VT-d is enabled (iommu=3Dpt intel_iommu=3Don), devices are 1:1 mapped.= In the Linux kernel unbinding devices from drivers removes that mapping which resu= lt in IOMMU errors. Introduced in Linux kernel 3.15 commit, solved in Linux ke= rnel 3.18 commit. Implication: Devices will not be allowed to access memory, resulting in following kernel errors: dmar: DRHD: handling fault status reg 2 dmar: DMAR:[DMA Read] Request device [02:00.0] fault addr a0c58000 DMAR:[fault reason 02] Present bit in context entry is clear Resolution/Workaround: Use earlier or later kernel versions, or avoid driver binding on boot by blacklisting the driver modules. I.e., in the case of ixgbe, we can pass the kernel command line option: modprobe.blacklist=3Dixgbe. This way we do not = need to unbind the device to bind it to igb_uio. Affected Environment/Platform: Linux systems with kernel versions 3.15 to 3.17. Driver/Module: igb_uio module. --=20 You are receiving this mail because: You are the assignee for the bug.= --17385539600.4C7d1dEa.2139567 Date: Mon, 3 Feb 2025 04:39:20 +0100 MIME-Version: 1.0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://bugs.dpdk.org/ Auto-Submitted: auto-generated X-Auto-Response-Suppress: All
Bug ID 1642
Summary Devices bound to igb_uio with VT-d enabled do not work on Lin= ux kernel 3.15-3.17
Product DPDK
Version unspecified
Hardware All
OS All
Status UNCONFIRMED
Severity normal
Priority Normal
Component vhost/virtio
Assignee dev@dpdk.org
Reporter nandinipersad361@gmail.com
Target Milestone --- 

When VT-d is enabled (iommu=3Dpt i=
ntel_iommu=3Don), devices are 1:1 mapped. In the
Linux kernel unbinding devices from drivers removes that mapping which resu=
lt
in IOMMU errors. Introduced in Linux kernel 3.15 commit, solved in Linux ke=
rnel
3.18 commit.

Implication:
Devices will not be allowed to access memory, resulting in following kernel
errors:

dmar: DRHD: handling fault status reg 2
dmar: DMAR:[DMA Read] Request device [02:00.0] fault addr a0c58000
DMAR:[fault reason 02] Present bit in context entry is clear
Resolution/Workaround:
Use earlier or later kernel versions, or avoid driver binding on boot by
blacklisting the driver modules. I.e., in the case of ixgbe, we can pass the
kernel command line option: modprobe.blacklist=3Dixgbe. This way we do not =
need
to unbind the device to bind it to igb_uio.

Affected Environment/Platform:
Linux systems with kernel versions 3.15 to 3.17.

Driver/Module:
igb_uio module.

You are receiving this mail because:
  • You are the assignee for the bug.
=20=20=20=20=20=20=20=20=20=20
= --17385539600.4C7d1dEa.2139567--