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From:   Jacob Pan <jacob.jun.pan@linux.intel.com>
To:     iommu@lists.linux-foundation.org,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        "Lu Baolu" <baolu.lu@linux.intel.com>,
        David Woodhouse <dwmw2@infradead.org>
Cc:     "Tian, Kevin" <kevin.tian@intel.com>,
        Raj Ashok <ashok.raj@intel.com>, "Yi Liu" <yi.l.liu@intel.com>,
        Eric Auger <eric.auger@redhat.com>,
        "Mehta, Sohil" <sohil.mehta@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH v3 5/8] iommu/vt-d: Fix off-by-one in PASID allocation
Date:   Tue, 19 Nov 2019 09:56:29 -0800
Message-Id: <1574186193-30457-6-git-send-email-jacob.jun.pan@linux.intel.com>
In-Reply-To: <1574186193-30457-1-git-send-email-jacob.jun.pan@linux.intel.com>
References: <1574186193-30457-1-git-send-email-jacob.jun.pan@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

PASID allocator uses IDR which is exclusive for the end of the
allocation range. There is no need to decrement pasid_max.

Fixes: af39507305fb ("iommu/vt-d: Apply global PASID in SVA")
Reported-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel-svm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 74df10a39dfc..e90d0b914afe 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -338,7 +338,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 		/* Do not use PASID 0 in caching mode (virtualised IOMMU) */
 		ret = intel_pasid_alloc_id(svm,
 					   !!cap_caching_mode(iommu->cap),
-					   pasid_max - 1, GFP_KERNEL);
+					   pasid_max, GFP_KERNEL);
 		if (ret < 0) {
 			kfree(svm);
 			kfree(sdev);
-- 
2.7.4