fix two flaws in the patch (93358e8e VT-d: introduce update_irte to update
irte safely).
Signed-off-by: Chao Gao <chao....@intel.com>
---
xen/drivers/passthrough/vtd/intremap.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/xen/drivers/passthrough/vtd/intremap.c
b/xen/drivers/passthrough/vtd/intremap.c
index 699239b..8649666 100644
--- a/xen/drivers/passthrough/vtd/intremap.c
+++ b/xen/drivers/passthrough/vtd/intremap.c
@@ -200,8 +200,9 @@ static void update_irte(struct iommu *iommu, struct
iremap_entry *entry,
else
{
/*
- * If the caller requests an atomic update but we can't meet it,
- * a bug will be raised.
+ * VT-d hardware doesn't update IRTEs behind us, nor the software.
+ * If a caller want an atomic update from the views of VT-d
+ * hardware, but we can't meet it, a bug will be raised.
*/
if ( entry->lo == new_ire->lo )
write_atomic(&entry->hi, new_ire->hi);
@@ -690,8 +691,7 @@ static int msi_msg_to_remap_entry(
remap_rte->data = index - i;
update_irte(iommu, iremap_entry, &new_ire, msi_desc->irte_initialized);
- if ( !msi_desc->irte_initialized )
- msi_desc->irte_initialized = true;
+ msi_desc->irte_initialized = true;
iommu_flush_cache_entry(iremap_entry, sizeof(*iremap_entry));
iommu_flush_iec_index(iommu, 0, index);
--
1.8.3.1
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