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smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KmlYJ0BY; 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="KmlYJ0BY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC3BEC433F1; Thu, 29 Feb 2024 21:07:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709240848; bh=J6nl5xudWoaHe5zt2ZmvKLymkNzx1v+WzoPkxo7Ue94=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=KmlYJ0BYjLjSdDhJPfMWjeAbasyaPJyxC5J5JG5g9OpaBI/OR5KF5myyHrzftRLKT 2d7M7lO5gv/wY3vsu9dOs+HU9cVpFI+2Lsea5uCZSwfPxH05KOrOAhVBUnqnaHZGx7 AaACX2V6QPzfh9/UcwVxDoseikUQz2j/mvH/n7Tfc1II+lw45KCiBnVECXD9KFFiky 403mfSB593j48zUgQkxtW24ECMmUNq440NoGr6WNlocpiZkhqmN+rjcMxQ1NRCJsHj ppa89wrCYjojAiPm8lKM+1dRhEF0s3tGyaSGiLIRKFC1qcIFpx6LxxEUbUmC3v3C6h oUmHBZwVqW3PQ== Date: Thu, 29 Feb 2024 15:07:26 -0600 From: Bjorn Helgaas To: Ethan Zhao Cc: baolu.lu@linux.intel.com, bhelgaas@google.com, robin.murphy@arm.com, jgg@ziepe.ca, kevin.tian@intel.com, dwmw2@infradead.org, will@kernel.org, lukas@wunner.de, yi.l.liu@intel.com, dan.carpenter@linaro.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iommu/vt-d: improve ITE fault handling if device was released Message-ID: <20240229210726.GA363458@bhelgaas> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240229040724.3393042-1-haifeng.zhao@linux.intel.com> On Wed, Feb 28, 2024 at 11:07:24PM -0500, Ethan Zhao wrote: > Break the loop to blindly retry the timeout ATS invalidation request > after ITE fault hit if device was released or isn't present anymore. > > This is part of the followup of prior proposed patchset > > https://do-db2.lkml.org/lkml/2024/2/22/350 Use lore URL, please. > Fixes: 6ba6c3a4cacf ("VT-d: add device IOTLB invalidation support") > Signed-off-by: Ethan Zhao > --- > drivers/iommu/intel/dmar.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c > index d14797aabb7a..d01d68205557 100644 > --- a/drivers/iommu/intel/dmar.c > +++ b/drivers/iommu/intel/dmar.c > @@ -1273,6 +1273,9 @@ static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index) > { > u32 fault; > int head, tail; > + u64 iqe_err, ite_sid; > + struct device *dev = NULL; > + struct pci_dev *pdev = NULL; > struct q_inval *qi = iommu->qi; > int shift = qi_shift(iommu); > > @@ -1317,6 +1320,13 @@ static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index) > tail = readl(iommu->reg + DMAR_IQT_REG); > tail = ((tail >> shift) - 1 + QI_LENGTH) % QI_LENGTH; > > + /* > + * SID field is valid only when the ITE field is Set in FSTS_REG > + * see Intel VT-d spec r4.1, section 11.4.9.9 > + */ > + iqe_err = dmar_readq(iommu->reg + DMAR_IQER_REG); > + ite_sid = DMAR_IQER_REG_ITESID(iqe_err); > + > writel(DMA_FSTS_ITE, iommu->reg + DMAR_FSTS_REG); > pr_info("Invalidation Time-out Error (ITE) cleared\n"); > > @@ -1326,6 +1336,21 @@ static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index) > head = (head - 2 + QI_LENGTH) % QI_LENGTH; > } while (head != tail); > > + /* > + * If got ITE, we need to check if the sid of ITE is one of the > + * current valid ATS invalidation target devices, if no, or the > + * target device isn't presnet, don't try this request anymore. > + * 0 value of ite_sid means old VT-d device, no ite_sid value. > + */ > + if (ite_sid) { > + dev = device_rbtree_find(iommu, ite_sid); > + if (!dev || !dev_is_pci(dev)) > + return -ETIMEDOUT; > + pdev = to_pci_dev(dev); > + if (!pci_device_is_present(pdev) && > + ite_sid == pci_dev_id(pci_physfn(pdev))) > + return -ETIMEDOUT; > + } > if (qi->desc_status[wait_index] == QI_ABORT) > return -EAGAIN; > } > -- > 2.31.1 >