From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83B59244670; Sun, 1 Mar 2026 01:44:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772329495; cv=none; b=Sb0GP4AcM9jzjmEx/ZI8tOmbysOcmnu3jdjCXsibWfn6Fb3jEV5NFM+3Z12yrUe6pq3iUeK9JviNbzXX6+ZIupDCa7KwOuTnznLoEVOJ5T6i/3QHt/ysuxUSMTGDCi4xo9t81KJSAcPy5Ws+xATwitwpr00YpKBn0ImlScAa2ZQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772329495; c=relaxed/simple; bh=Zquc+/111xkDdU0/8MD6IGvfZRVRniKj49fw13tZUlo=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=DVt/NCRrxD6fbJwho2VwINhet/8LrxWoCrMumGVWU82Ixsz6GFbMhFTGY+ZLLytcwSBt2g+gSCl+P1K6R/nVA1Hx4+nRbRG4jO7EXuxECGIxWBANNt6Y6PvRsfxrW2EbMgT4jtia7QeBQ2wrNi0EGySUv29HVt+p0UzEtCPzOMA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LsRRA6tp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LsRRA6tp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A2FBC19421; Sun, 1 Mar 2026 01:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772329495; bh=Zquc+/111xkDdU0/8MD6IGvfZRVRniKj49fw13tZUlo=; h=From:To:Cc:Subject:Date:From; b=LsRRA6tp0wWBsNNa7DNKM7gzR3MElvzUIYX4RNVDKt7q7JZ7yWcfxlCtR34qjP/X7 FJWnD4lUqSgRbdOW6hbDFgjDiCqc9cv0aXVNFnMIJhjgzVTEaFAvIxcS3UAwUdk62w aOhBEVcjNT9uOUOayEJi7gBY5tOQ4BaWsMOgPjW72QP0eERQqyKVABH5gPaFUrkTp2 hIwoTIhY5jZR6yp14EgpRKhiq7n7Ph1n1ToBEO3gUIVY5leucW6W60Jas5VQc/AfCl NOmzP9ndeme3BXJAsWIkH3ftIXTTUaZ2grC0awnmb5MYPVeYji70/DRZONrff2HQZL NpI34MWhVd3FQ== From: Sasha Levin To: stable@vger.kernel.org, schnelle@linux.ibm.com Cc: Benjamin Block , Bjorn Helgaas , Gerd Bayer , linux-pci@vger.kernel.org Subject: FAILED: Patch "PCI/IOV: Fix race between SR-IOV enable/disable and hotplug" failed to apply to 6.1-stable tree Date: Sat, 28 Feb 2026 20:44:53 -0500 Message-ID: <20260301014453.1707344-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Hint: ignore X-stable: review Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From a5338e365c4559d7b4d7356116b0eb95b12e08d5 Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Tue, 16 Dec 2025 23:14:03 +0100 Subject: [PATCH] PCI/IOV: Fix race between SR-IOV enable/disable and hotplug Commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV") tried to fix a race between the VF removal inside sriov_del_vfs() and concurrent hot unplug by taking the PCI rescan/remove lock in sriov_del_vfs(). Similarly the PCI rescan/remove lock was also taken in sriov_add_vfs() to protect addition of VFs. This approach however causes deadlock on trying to remove PFs with SR-IOV enabled because PFs disable SR-IOV during removal and this removal happens under the PCI rescan/remove lock. So the original fix had to be reverted. Instead of taking the PCI rescan/remove lock in sriov_add_vfs() and sriov_del_vfs(), fix the race that occurs with SR-IOV enable and disable vs hotplug higher up in the callchain by taking the lock in sriov_numvfs_store() before calling into the driver's sriov_configure() callback. Fixes: 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV") Reported-by: Benjamin Block Signed-off-by: Niklas Schnelle Signed-off-by: Bjorn Helgaas Reviewed-by: Benjamin Block Reviewed-by: Gerd Bayer Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251216-revert_sriov_lock-v3-2-dac4925a7621@linux.ibm.com --- drivers/pci/iov.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 7de5b18647beb..4a659c34935e1 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -495,7 +495,9 @@ static ssize_t sriov_numvfs_store(struct device *dev, if (num_vfs == 0) { /* disable VFs */ + pci_lock_rescan_remove(); ret = pdev->driver->sriov_configure(pdev, 0); + pci_unlock_rescan_remove(); goto exit; } @@ -507,7 +509,9 @@ static ssize_t sriov_numvfs_store(struct device *dev, goto exit; } + pci_lock_rescan_remove(); ret = pdev->driver->sriov_configure(pdev, num_vfs); + pci_unlock_rescan_remove(); if (ret < 0) goto exit; -- 2.51.0