VT-d/ATS: correct and clean up dev_invalidate_iotlb()

While this was intended to only do cleanup (replace the two bogus
"ret |= " constructs, and a simple formatting correction), this now
also
- fixes the bit manipulations for size_order > 0
  a) correct an off-by-one in the use of size_order for shifting (till
     now double the requested size got invalidated)
  b) in fact setting bit 12 and up if necessary (without which too
     small a region might have got invalidated)
  c) making them capable of dealing with regions of 4Gb size and up
- corrects the return value handling, such that a later iteration's
  success won't clear an earlier iteration's error indication
- uses PCI_BDF2() instead of open coding it
- bail immediately on bad passed in invalidation type, rather than
  repeatedly printing the same message for each ATS-capable device, at
  once also no longer hiding that failure from the caller

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Yang Zhang <yang.z.zhang@intel.com>
master commit: fd33987ba27607c3cc7da258cf1d86d21beeb735
master date: 2014-06-30 15:57:40 +0200

diff --git a/xen/drivers/passthrough/vtd/x86/ats.c b/xen/drivers/passthrough/vtd/x86/ats.c
index ea57d7d29f77123a0bbc92afb1265f3aed4fa25d..6b0632b39221f221ce1168e8273edf2a8f0755ae 100644 (file)
--- a/xen/drivers/passthrough/vtd/x86/ats.c
+++ b/xen/drivers/passthrough/vtd/x86/ats.c
@@ -110,21 +110,23 @@ int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
     u64 addr, unsigned int size_order, u64 type)
 {
     struct pci_ats_dev *pdev;
-    int sbit, ret = 0;
-    u16 sid;
+    int ret = 0;
 
     if ( !ecap_dev_iotlb(iommu->ecap) )
         return ret;
 
     list_for_each_entry( pdev, &ats_devices, list )
     {
-        sid = (pdev->bus << 8) | pdev->devfn;
+        u16 sid = PCI_BDF2(pdev->bus, pdev->devfn);
+        bool_t sbit;
+        int rc = 0;
 
         /* Only invalidate devices that belong to this IOMMU */
         if ( pdev->iommu != iommu )
             continue;
 
-        switch ( type ) {
+        switch ( type )
+        {
         case DMA_TLB_DSI_FLUSH:
             if ( !device_in_domain(iommu, pdev, did) )
                 break;
@@ -133,32 +135,37 @@ int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
             /* invalidate all translations: sbit=1,bit_63=0,bit[62:12]=1 */
             sbit = 1;
             addr = (~0 << PAGE_SHIFT_4K) & 0x7FFFFFFFFFFFFFFF;
-            ret |= qinval_device_iotlb(iommu, pdev->ats_queue_depth,
-                                       sid, sbit, addr);
+            rc = qinval_device_iotlb(iommu, pdev->ats_queue_depth,
+                                     sid, sbit, addr);
             break;
         case DMA_TLB_PSI_FLUSH:
             if ( !device_in_domain(iommu, pdev, did) )
                 break;
 
-            addr &= ~0 << (PAGE_SHIFT + size_order);
-
             /* if size <= 4K, set sbit = 0, else set sbit = 1 */
             sbit = size_order ? 1 : 0;
 
             /* clear lower bits */
-            addr &= (~0 << (PAGE_SHIFT + size_order));
+            addr &= ~0 << PAGE_SHIFT_4K;
 
             /* if sbit == 1, zero out size_order bit and set lower bits to 1 */
             if ( sbit )
-                addr &= (~0  & ~(1 << (PAGE_SHIFT + size_order)));
+            {
+                addr &= ~((u64)PAGE_SIZE_4K << (size_order - 1));
+                addr |= (((u64)1 << (size_order - 1)) - 1) << PAGE_SHIFT_4K;
+            }
 
-            ret |= qinval_device_iotlb(iommu, pdev->ats_queue_depth,
-                                       sid, sbit, addr);
+            rc = qinval_device_iotlb(iommu, pdev->ats_queue_depth,
+                                     sid, sbit, addr);
             break;
         default:
             dprintk(XENLOG_WARNING VTDPREFIX, "invalid vt-d flush type\n");
-            break;
+            return -EOPNOTSUPP;
         }
+
+        if ( !ret )
+            ret = rc;
     }
+
     return ret;
 }