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 7814C37146D; Sat, 28 Feb 2026 17:57:43 +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=1772301463; cv=none; b=hk+agu1GmJlVv/Qgw1qnk8RirExAFe/0vRlplRCGjElsNP0eQ3HwKA72zDMa/pNSwHBuAIwY3tSMthVPLA4tsg89kmUbiUkuJsQm1p2TvN5g+oh3kT4aKoV4kAwg8OyR1uTfeWbHhoI0o239bB/k2fKFdzMowwADSVetzhwWVoQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772301463; c=relaxed/simple; bh=G9GwIaJ9gIxZ5AmUoyBqSUEXGS6+56r2NwHTvwc+K7c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dfgf8k9fRZitUsQKthkLnZzCdHppMuKj2g/ollRcoTuhSgTEdZS8eRD3LwAl2fTrAJgFPehDqa965IEPFhoJtink6950nT5RLzYF6wkbqBMlLVkZH4BEvNv2NBgO6P2lyLdUfjYWY+R8Rr0EiZZHlnxyokPhYOvf8/eqdD9Ih24= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cngIKhSO; 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="cngIKhSO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DC02C116D0; Sat, 28 Feb 2026 17:57:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772301463; bh=G9GwIaJ9gIxZ5AmUoyBqSUEXGS6+56r2NwHTvwc+K7c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cngIKhSO/9DUB48p1SvFvaUcxkPLbAiTeXUJSH21z7TIWiFseiJlXKszgHWd764IK vjGwuHU070lF5X07PVKWPoCikzy+Y3v49uXF/6RS3th9Y69nbYAYjJ2eo4VsVgPaqq 4eZQQr+hWNtAQF/7ExuP5MZjJhm5ARPY8GHdW4kvjCiEcXmEtu+KmXWufSToEylT4M cbaidNa2aplCE9X36GWdtFSBJV9KygQ1z7aXlJRDHzD/3VZcubpcNAUb/n3G2PAqks FCPBZj9m6Zib1EysldqZKtejWNPVSkMwQWhBeqozxUldm39QuNictcZ39Kw79mj8JN mK0bHRDZcp24w== From: Sasha Levin To: patches@lists.linux.dev Cc: Niklas Schnelle , Benjamin Block , Bjorn Helgaas , Gerd Bayer , stable@vger.kernel.org, Sasha Levin Subject: [PATCH 6.18 648/752] PCI/IOV: Fix race between SR-IOV enable/disable and hotplug Date: Sat, 28 Feb 2026 12:45:59 -0500 Message-ID: <20260228174750.1542406-648-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228174750.1542406-1-sashal@kernel.org> References: <20260228174750.1542406-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Niklas Schnelle [ Upstream commit a5338e365c4559d7b4d7356116b0eb95b12e08d5 ] 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 Signed-off-by: Sasha Levin --- drivers/pci/iov.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ac4375954c947..c6dc1b44bf602 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