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From:   Niklas Schnelle <schnelle@linux.ibm.com>
Date:   Mon, 15 May 2023 11:15:53 +0200
Subject: [PATCH v9 3/6] s390/pci: prepare is_passed_through() for dma-iommu
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To:     Joerg Roedel <joro@8bytes.org>,
        Matthew Rosato <mjrosato@linux.ibm.com>,
        Will Deacon <will@kernel.org>,
        Wenjia Zhang <wenjia@linux.ibm.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Jason Gunthorpe <jgg@ziepe.ca>
Cc:     Gerd Bayer <gbayer@linux.ibm.com>,
        Julian Ruess <julianr@linux.ibm.com>,
        Pierre Morel <pmorel@linux.ibm.com>,
        Alexandra Winter <wintera@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
        Hector Martin <marcan@marcan.st>,
        Sven Peter <sven@svenpeter.dev>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        David Woodhouse <dwmw2@infradead.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Yong Wu <yong.wu@mediatek.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
        Orson Zhai <orsonzhai@gmail.com>,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        Chunyan Zhang <zhang.lyra@gmail.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Samuel Holland <samuel@sholland.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Krishna Reddy <vdumpa@nvidia.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Niklas Schnelle <schnelle@linux.ibm.com>,
        Jonathan Corbet <corbet@lwn.net>, linux-s390@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        iommu@lists.linux.dev, asahi@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org,
        linux-arm-msm@vger.kernel.org, linux-mediatek@lists.infradead.org,
        linux-sunxi@lists.linux.dev, linux-tegra@vger.kernel.org,
        linux-doc@vger.kernel.org
Precedence: bulk

With the IOMMU always controlled through the IOMMU driver testing for
zdev->s390_domain is not a valid indication of the device being
passed-through. Instead test if zdev->kzdev is set.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 arch/s390/pci/pci_event.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index b9324ca2eb94..4ef5a6a1d618 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -59,9 +59,16 @@ static inline bool ers_result_indicates_abort(pci_ers_result_t ers_res)
 	}
 }
 
-static bool is_passed_through(struct zpci_dev *zdev)
+static bool is_passed_through(struct pci_dev *pdev)
 {
-	return zdev->s390_domain;
+	struct zpci_dev *zdev = to_zpci(pdev);
+	bool ret;
+
+	mutex_lock(&zdev->kzdev_lock);
+	ret = !!zdev->kzdev;
+	mutex_unlock(&zdev->kzdev_lock);
+
+	return ret;
 }
 
 static bool is_driver_supported(struct pci_driver *driver)
@@ -176,7 +183,7 @@ static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev)
 	}
 	pdev->error_state = pci_channel_io_frozen;
 
-	if (is_passed_through(to_zpci(pdev))) {
+	if (is_passed_through(pdev)) {
 		pr_info("%s: Cannot be recovered in the host because it is a pass-through device\n",
 			pci_name(pdev));
 		goto out_unlock;
@@ -239,7 +246,7 @@ static void zpci_event_io_failure(struct pci_dev *pdev, pci_channel_state_t es)
 	 * we will inject the error event and let the guest recover the device
 	 * itself.
 	 */
-	if (is_passed_through(to_zpci(pdev)))
+	if (is_passed_through(pdev))
 		goto out;
 	driver = to_pci_driver(pdev->dev.driver);
 	if (driver && driver->err_handler && driver->err_handler->error_detected)

-- 
2.39.2