From: bugzilla-daemon@kernel.org
To: kvm@vger.kernel.org
Subject: [Bug 220776] When passthrough device to KVM guest with iommufd+hugepage, more hugepage are used than assigned, and DMAR error reported from host dmesg
Date: Tue, 11 Nov 2025 09:01:27 +0000 [thread overview]
Message-ID: <bug-220776-28872-BlSJOmrKdb@https.bugzilla.kernel.org/> (raw)
In-Reply-To: <bug-220776-28872@https.bugzilla.kernel.org/>
https://bugzilla.kernel.org/show_bug.cgi?id=220776
chenyi.qiang@intel.com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |chenyi.qiang@intel.com
--- Comment #1 from chenyi.qiang@intel.com ---
After some bisect, it is found that this issue is introduced by the support of
dma_map_file in iommufd [1][2]. With hugetlbfs as backend, it will go to the
path of IOMMU_IOAS_MAP_FILE ioctl. If we fallback to the IOMMU_IOAS_MAP ioctl,
there's no such problem.
[1]
https://lore.kernel.org/qemu-devel/1751493538-202042-9-git-send-email-steven.sistare@oracle.com/
[2]
https://lore.kernel.org/all/1729861919-234514-1-git-send-email-steven.sistare@oracle.com/
--
You may reply to this email to add a comment.
You are receiving this mail because:
You are watching the assignee of the bug.
next prev parent reply other threads:[~2025-11-11 9:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-11 7:48 [Bug 220776] New: When passthrough device to KVM guest with iommufd+hugepage, more hugepage are used than assigned, and DMAR error reported from host dmesg bugzilla-daemon
2025-11-11 9:01 ` bugzilla-daemon [this message]
2025-11-13 6:30 ` [Bug 220776] " Chen, Farrah
2025-11-13 6:30 ` bugzilla-daemon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=bug-220776-28872-BlSJOmrKdb@https.bugzilla.kernel.org/ \
--to=bugzilla-daemon@kernel.org \
--cc=kvm@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox