From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 5 Apr 2022 12:44:53 +0000 (+0200)
Subject: VT-d: fix add/remove ordering when RMRRs are in use
X-Git-Tag: archive/raspbian/4.16.1-1+rpi1^2~38^2~24
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=cf0dc7379b9e2aa5f4b3983d81c6e2ed9811c34f;p=xen.git

VT-d: fix add/remove ordering when RMRRs are in use

In the event that the RMRR mappings are essential for device operation,
they should be established before updating the device's context entry,
while they should be torn down only after the device's context entry was
successfully cleared.

Also switch to %pd in related log messages.

Fixes: fa88cfadf918 ("vt-d: Map RMRR in intel_iommu_add_device() if the device has RMRR")
Fixes: 8b99f4400b69 ("VT-d: fix RMRR related error handling")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
master commit: 3221f270cf2eba0a22fd4f92319d664eacb92889
master date: 2022-04-05 14:16:10 +0200
---

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 5e3740feb6..19696a8818 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1997,14 +1997,6 @@ static int intel_iommu_add_device(u8 devfn, struct pci_dev *pdev)
     if ( !pdev->domain )
         return -EINVAL;
 
-    ret = domain_context_mapping(pdev->domain, devfn, pdev);
-    if ( ret )
-    {
-        dprintk(XENLOG_ERR VTDPREFIX, "d%d: context mapping failed\n",
-                pdev->domain->domain_id);
-        return ret;
-    }
-
     for_each_rmrr_device ( rmrr, bdf, i )
     {
         if ( rmrr->segment == pdev->seg &&
@@ -2021,12 +2013,17 @@ static int intel_iommu_add_device(u8 devfn, struct pci_dev *pdev)
                                          rmrr->base_address, rmrr->end_address,
                                          0);
             if ( ret )
-                dprintk(XENLOG_ERR VTDPREFIX, "d%d: RMRR mapping failed\n",
-                        pdev->domain->domain_id);
+                dprintk(XENLOG_ERR VTDPREFIX, "%pd: RMRR mapping failed\n",
+                        pdev->domain);
         }
     }
 
-    return 0;
+    ret = domain_context_mapping(pdev->domain, devfn, pdev);
+    if ( ret )
+        dprintk(XENLOG_ERR VTDPREFIX, "%pd: context mapping failed\n",
+                pdev->domain);
+
+    return ret;
 }
 
 static int intel_iommu_enable_device(struct pci_dev *pdev)
@@ -2048,11 +2045,15 @@ static int intel_iommu_remove_device(u8 devfn, struct pci_dev *pdev)
 {
     struct acpi_rmrr_unit *rmrr;
     u16 bdf;
-    int i;
+    int ret, i;
 
     if ( !pdev->domain )
         return -EINVAL;
 
+    ret = domain_context_unmap(pdev->domain, devfn, pdev);
+    if ( ret )
+        return ret;
+
     for_each_rmrr_device ( rmrr, bdf, i )
     {
         if ( rmrr->segment != pdev->seg ||
@@ -2068,7 +2069,7 @@ static int intel_iommu_remove_device(u8 devfn, struct pci_dev *pdev)
                                rmrr->end_address, 0);
     }
 
-    return domain_context_unmap(pdev->domain, devfn, pdev);
+    return 0;
 }
 
 static int __hwdom_init setup_hwdom_device(u8 devfn, struct pci_dev *pdev)