From: Steve Rutherford <srutherford@google.com>
To: anthony.l.nguyen@intel.com, przemyslaw.kitszel@intel.com,
aleksander.lobakin@intel.com
Cc: andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
Steve Rutherford <srutherford@google.com>
Subject: [RFC PATCH 0/1] IDPF + SWIOTLB Bug
Date: Fri, 27 Feb 2026 02:59:49 +0000 [thread overview]
Message-ID: <20260227025950.174755-1-srutherford@google.com> (raw)
Found an issue with the IDPF driver when SWIOTLB is enabled. The issue
results in empty headers for packets that hit the split queue workaround
path. It's caused by a spurious sync in that path. The header is synced
from the SWIOTLB even when the header was shoved into the payload.
I cooked up a sample patch, but I'm not an expert in this driver, so I have
no idea if it's the right solution. It did allow my QEMU VM to boot with a
superficially functional passed-through IDPF NIC and SWIOTLB=force.
The patch was written against COS's 6.12, so I assume that it will not
apply cleanly elsewhere, but I figured a wrong sample patch was better than
a long paragraph describing the same thing. My read of more recent kernels
is that this problem is still present, but could be mistaken.
Steve Rutherford (1):
Fix header clobber in IDPF with SWIOTLB enabled
drivers/net/ethernet/intel/idpf/idpf_txrx.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--
2.53.0.473.g4a7958ca14-goog
next reply other threads:[~2026-02-27 2:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-27 2:59 Steve Rutherford [this message]
2026-02-27 2:59 ` [RFC PATCH 1/1] Fix header clobber in IDPF with SWIOTLB enabled Steve Rutherford
2026-02-27 17:07 ` [Intel-wired-lan] " Loktionov, Aleksandr
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