[Xen-devel] [PATCH v6 6/7] VT-d: Some cleanups

[Feng Wu <feng.wu@xxxxxxxxx>]

Use type-safe structure assignment instead of memcpy()
Use sizeof(*iremap_entry). Besides that, this patch also
handle another cleanup, in msi_msg_to_remap_entry() we don't
need to copy all the content of old IRTE to the new IRE, we
only need to save the 'IM' field to 'new_ire' if the entry
is present.

Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
---
v6:
- More descripion about the patch

 xen/drivers/passthrough/vtd/intremap.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/intremap.c 
b/xen/drivers/passthrough/vtd/intremap.c
index 97e80a6..39dcb3a 100644
--- a/xen/drivers/passthrough/vtd/intremap.c
+++ b/xen/drivers/passthrough/vtd/intremap.c
@@ -183,8 +183,8 @@ static void free_remap_entry(struct iommu *iommu, int index)
     GET_IREMAP_ENTRY(ir_ctrl->iremap_maddr, index,
                      iremap_entries, iremap_entry);
 
-    memset(iremap_entry, 0, sizeof(struct iremap_entry));
-    iommu_flush_cache_entry(iremap_entry, sizeof(struct iremap_entry));
+    memset(iremap_entry, 0, sizeof(*iremap_entry));
+    iommu_flush_cache_entry(iremap_entry, sizeof(*iremap_entry));
     iommu_flush_iec_index(iommu, 0, index);
 
     unmap_vtd_domain_page(iremap_entries);
@@ -310,7 +310,7 @@ static int ioapic_rte_to_remap_entry(struct iommu *iommu,
     GET_IREMAP_ENTRY(ir_ctrl->iremap_maddr, index,
                      iremap_entries, iremap_entry);
 
-    memcpy(&new_ire, iremap_entry, sizeof(struct iremap_entry));
+    new_ire = *iremap_entry;
 
     if ( rte_upper )
     {
@@ -353,8 +353,8 @@ static int ioapic_rte_to_remap_entry(struct iommu *iommu,
         remap_rte->format = 1;    /* indicate remap format */
     }
 
-    memcpy(iremap_entry, &new_ire, sizeof(struct iremap_entry));
-    iommu_flush_cache_entry(iremap_entry, sizeof(struct iremap_entry));
+    *iremap_entry = new_ire;
+    iommu_flush_cache_entry(iremap_entry, sizeof(*iremap_entry));
     iommu_flush_iec_index(iommu, 0, index);
 
     unmap_vtd_domain_page(iremap_entries);
@@ -643,7 +643,8 @@ static int msi_msg_to_remap_entry(
     GET_IREMAP_ENTRY(ir_ctrl->iremap_maddr, index,
                      iremap_entries, iremap_entry);
 
-    memcpy(&new_ire, iremap_entry, sizeof(struct iremap_entry));
+    if ( iremap_entry->remap.p )
+        new_ire.remap.im = iremap_entry->remap.im;
 
     /* Set interrupt remapping table entry */
     new_ire.remap.fpd = 0;
@@ -691,8 +692,8 @@ static int msi_msg_to_remap_entry(
              new_ire.remap.p && !new_ire.remap.im )
             pi_get_new_irte(&new_ire, iremap_entry);
 
-        memcpy(iremap_entry, &new_ire, sizeof(struct iremap_entry));
-        iommu_flush_cache_entry(iremap_entry, sizeof(struct iremap_entry));
+        *iremap_entry = new_ire;
+        iommu_flush_cache_entry(iremap_entry, sizeof(*iremap_entry));
         iommu_flush_iec_index(iommu, 0, index);
     }
 
-- 
2.1.0


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