From: Keir Fraser <keir.fraser@citrix.com>
Date: Tue, 13 Jan 2009 15:16:07 +0000 (+0000)
Subject: AMD IOMMU: Fix a dead lock in device assignment.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14014^2~73
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=334ed7f65e426e7acd7923a23054294de9a4293a;p=xen.git

AMD IOMMU: Fix a dead lock in device assignment.

Do not obtain pcidevs_lock in reassign_device().

Signed-off-by: Wei Wang <wei.wang2@amd.com>
---

diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index ec26a9a19d..53eff979a4 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -271,26 +271,22 @@ static int reassign_device( struct domain *source, struct domain *target,
     struct amd_iommu *iommu;
     int bdf;
 
-    spin_lock(&pcidevs_lock);
+    ASSERT(spin_is_locked(&pcidevs_lock));
     pdev = pci_get_pdev_by_domain(source, bus, devfn);
     if ( !pdev )
-    {
-        spin_unlock(&pcidevs_lock);
         return -ENODEV;
-    }
 
     bdf = (bus << 8) | devfn;
     /* supported device? */
     iommu = (bdf < ivrs_bdf_entries) ?
-	find_iommu_for_device(bus, pdev->devfn) : NULL;
+    find_iommu_for_device(bus, pdev->devfn) : NULL;
 
     if ( !iommu )
     {
-        spin_unlock(&pcidevs_lock);
         amd_iov_error("Fail to find iommu."
-		      " %x:%x.%x cannot be assigned to domain %d\n", 
-		      bus, PCI_SLOT(devfn), PCI_FUNC(devfn), target->domain_id);
-	return -ENODEV;
+            " %x:%x.%x cannot be assigned to domain %d\n", 
+            bus, PCI_SLOT(devfn), PCI_FUNC(devfn), target->domain_id);
+        return -ENODEV;
     }
 
     amd_iommu_disable_domain_device(source, iommu, bdf);