[Xen-devel] [PATCH v2 06/11] vpci/header: add teardown cleanup

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

In order to unmap the BARs

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
---
Changes since v1:
 - Add comment regarding the fact that memory decoding is not
   disabled when removing a device.
---
 xen/drivers/vpci/header.c | 35 ++++++++++++++++++++++++++++-------
 1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index 4363270a55..17a9dbb0bf 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -131,12 +131,15 @@ bool vpci_process_pending(struct vcpu *v)
         if ( rc == -ERESTART )
             return true;
 
-        spin_lock(&v->vpci.pdev->vpci_lock);
-        if ( v->vpci.pdev->vpci )
-            /* Disable memory decoding unconditionally on failure. */
-            modify_decoding(v->vpci.pdev, !rc && v->vpci.map,
-                            !rc && v->vpci.rom_only);
-        spin_unlock(&v->vpci.pdev->vpci_lock);
+        if ( v->vpci.pdev )
+        {
+            spin_lock(&v->vpci.pdev->vpci_lock);
+            if ( v->vpci.pdev->vpci )
+                /* Disable memory decoding unconditionally on failure. */
+                modify_decoding(v->vpci.pdev, !rc && v->vpci.map,
+                                !rc && v->vpci.rom_only);
+            spin_unlock(&v->vpci.pdev->vpci_lock);
+        }
 
         rangeset_destroy(v->vpci.mem);
         v->vpci.mem = NULL;
@@ -560,7 +563,25 @@ static int init_bars(struct pci_dev *pdev)
 
     return (cmd & PCI_COMMAND_MEMORY) ? modify_bars(pdev, true, false) : 0;
 }
-REGISTER_VPCI_INIT(init_bars, NULL, VPCI_PRIORITY_MIDDLE);
+
+static void teardown_bars(struct pci_dev *pdev)
+{
+    uint16_t cmd = pci_conf_read16(pdev->seg, pdev->bus, PCI_SLOT(pdev->devfn),
+                                   PCI_FUNC(pdev->devfn), PCI_COMMAND);
+
+    if ( cmd & PCI_COMMAND_MEMORY )
+    {
+        /* Unmap all BARs from guest p2m. */
+        modify_bars(pdev, false, false);
+        /*
+         * Since this operation is deferred at the point when it finishes the
+         * device might have been removed, so don't attempt to disable memory
+         * decoding afterwards.
+         */
+        current->vpci.pdev = NULL;
+    }
+}
+REGISTER_VPCI_INIT(init_bars, teardown_bars, VPCI_PRIORITY_MIDDLE);
 
 /*
  * Local variables:
-- 
2.17.1


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