From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794047626; b=zCMIG3m8DSGtsvwIxLTKIv/H9QOmdDt42evFrtyU7tY9Hh60XD35cy9t5MzfTcaINDbJ R8wjSBvVCrP8JZIBmHlD0HxtxNisU+LXubAzfVkXq+vIfrMSMLrryVtHj2XloKlxGBgrT O/eUkUsqba+9Owb1gla/8uadIHQk1/31+9PL5j1HN5QuLL5nvtXeQTHA/vFAOR+UuR0YV V/fI7a1CgoU4mZwdFaWN1lqfZGw3ifXNxULMvTOg8OOBvIzTU8gBZQMLj06zTnavT6wO+ 0vzMbI7HzZmwglrvgnyS4YXpZCJUHDj8mMPB8QbY54D+H4JxVhzDkzRDA9P7KfmWJgQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047626; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=u4atQQg3s6WzRNzGY4nczJl7wB1smd47eqgk2dbMoJs=; b=KGYn9Yo3cI365IK6cEYkaTiKnfx8W64v+SiYJ9PVnpodTa8e9hsAzrl6CcoGX4jyUGRM vKKFgbcOTMZB3p4ddcRJ1u3A60i2rG4G0dYOUcWksB4raV4Bfhr3vENQ3PKi5uNrLqChm 8vyMWmVuqN+xLQIQnR2CJR6pTDWqIJqmYTExEH1qywZHzZ+CSmzRukMOD2jNyCx0TvRZK d1b03ek5e6Eilh19fdU6wiBl8zsEwQfvRNcZFhPhkPW/u4AOke+Djfpiq81B2XMYc7Rb9 QEE0WzDAOHRCTMZMap3KvsdsZ0zN5jpfrZec2N2PGMHHFND7Z+wDV8zQbS4+n9EFNpw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lJdQWoO4; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BDEA9606A32C for ; Sat, 7 Nov 2026 10:33:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lJdQWoO4 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CD541F0089F; Sat, 7 Nov 2026 10:33:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047625; bh=u4atQQg3s6WzRNzGY4nczJl7wB1smd47eqgk2dbMoJs=; h=From:To:Cc:Subject:Date; b=lJdQWoO4Ts7jHLKQ4YCAq2j43u2t0C68swReWhqK4FBvUy+2xFQO6+A0YPAxQvhJB Gr8kUS/k4iSG0TeZeE1AQ29rHxgo7zGYVX7vhjIgjNrKc+cxwKYmoTF7Ap6IBPqBbI qhbXvylaxrTQ5fYtDeaFYbCZ5D2WTHhZMfgvZRQf2yyPq58zO1vwHMZoJS4plPfT18 +IUbKTgKsFHHVEEd4WVqOfL4jLj8fiTHArz8oOZh9wdGpSZorfRKESFqIDkMokbsLO rbyF2NdtFrZUWvDnwbxgeyKR+fnL7Rsb4yqF+lT6XxOKf6luAhzLxYyiCT17QBbllW 7y0rAoT4w4P8w== From: Sasha Levin To: gvozd188@mail.ru, bhelgaas@google.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] PCI: vmd: Flush DMA writes before handling MSI on Arrow Lake" failed to apply to 6.6-stable tree Date: Sat, 7 Nov 2026 05:33:44 -0500 Message-ID: <20261107053344-failed-6.6-2c88c2dc1852@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-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 . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 2c88c2dc18528489b403fe95741f5731e292f7ba # git commit -s git send-email --to '' --in-reply-to '20261107053344-failed-6.6-2c88c2dc1852@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 2c88c2dc18528489b403fe95741f5731e292f7ba Mon Sep 17 00:00:00 2001 From: Vladimir Nedoshivin Date: Fri, 11 Sep 2026 00:05:39 +0400 Subject: [PATCH] PCI: vmd: Flush DMA writes before handling MSI on Arrow Lake MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Per the Intel Core Ultra Processors (Series 2) Specification Update (ID 834774 of 9/1/2026), the Arrow Lake VMD device 0xad0b is affected by an MSI erratum: ARL004: MSI from VMD-Owned Device May Pass Memory Write Problem When the storage subsystem is configured to operate in RAID 0 or 1 mode, a Message Signaled Interrupt (MSI) from an Intel® Volume Management Device (Intel® VMD) owned device may interrupt a core before a previous write from the device is completed. Workaround None identified. The VMD MSI interrupt-handler should initially perform a dummy register read to the MSI initiator device prior to any writes to ensure proper PCIe ordering. The existing VMD_FEAT_INTERRUPT_QUIRK implements Intel's documented workaround by issuing a configuration-space read to the MSI initiator before dispatching the interrupt. Enable the existing quirk for 0xad0b as well as 0x7d0b and make the comments describe both MTL016 and ARL004. Tested on an MSI Vector 17 HX AI with Intel VMD 8086:ad0b and an NVMe device behind VMD. With the quirk enabled, the NVMe completion stalls observed without the workaround are no longer reproduced. Link: https://bugs.launchpad.net/bugs/2166325 Signed-off-by: Vladimir Nedoshivin [bhelgaas: include erratum source and text, cc: stable] Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260910200539.10862-1-gvozd188@mail.ru --- drivers/pci/controller/vmd.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index e45ef8cb16e47..9d97a832785ee 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -94,7 +94,8 @@ enum vmd_features { VMD_FEAT_USE_BIOS_INFO = (1 << 6), /* - * Meteor Lake VMD (device ID 0x7d0b) is affected by erratum MTL016: + * Some Intel VMD devices are affected by interrupt ordering errata, + * including MTL016 (0x7d0b) and ARL004 (0xad0b): * the VMD may signal its MSI before the posted writes that carry the * child device's DMA data have landed in memory. The demuxed handler * then runs against a not-yet-coherent completion queue and misses the @@ -131,7 +132,7 @@ static DEFINE_RAW_SPINLOCK(list_lock); * @enabled: true if driver enabled IRQ * @virq: the virtual IRQ value provided to the requesting driver. * @flush_addr: config space address of the initiating device, read before - * demuxing to flush its posted writes (MTL016); NULL if the + * demuxing to flush its posted writes; NULL if the * VMD is not affected. * * Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to @@ -1300,7 +1301,7 @@ static const struct pci_device_id vmd_ids[] = { {PCI_VDEVICE(INTEL, 0x7d0b), .driver_data = VMD_FEATS_CLIENT | VMD_FEAT_INTERRUPT_QUIRK,}, {PCI_VDEVICE(INTEL, 0xad0b), - .driver_data = VMD_FEATS_CLIENT,}, + .driver_data = VMD_FEATS_CLIENT | VMD_FEAT_INTERRUPT_QUIRK,}, {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B), .driver_data = VMD_FEATS_CLIENT,}, {PCI_VDEVICE(INTEL, 0xb60b), -- 2.53.0