From: Dongli Zhang <dongli.zh...@oracle.com>
In msix_exclusive_bar the bar_pba_size is more than what the pba is
expected to have, although this never affects the bar size.
Specifically, the math in msix_init_exclusive_bar allocates too much
memory in some cases.
For example consider nentries = 8. msix_exclusive_bar will give us
bar_pba_size = 16. So 16 bytes. However 8 bytes would be enough - this
is all that the spec requires.
So in practice bar_pba_size sometimes allocates an extra 8 bytes but
never more.
Since each MSIX entry size is 16 bytes, and since we make sure that
table+pba is a power of two, this always leaves a multiple of 16 bytes
for the PBA, so extra 8 bytes have no effect.
However, its ugly to have pba size temporary variable have an incorrect
value. For consistency switch to the formula used in msix_init.
Signed-off-by: Dongli Zhang <dongli.zh...@oracle.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
hw/pci/msix.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/pci/msix.c b/hw/pci/msix.c
index c7bdbeda9e..4e336416a7 100644
--- a/hw/pci/msix.c
+++ b/hw/pci/msix.c
@@ -345,7 +345,7 @@ int msix_init_exclusive_bar(PCIDevice *dev, unsigned short
nentries,
char *name;
uint32_t bar_size = 4096;
uint32_t bar_pba_offset = bar_size / 2;
- uint32_t bar_pba_size = (nentries / 8 + 1) * 8;
+ uint32_t bar_pba_size = QEMU_ALIGN_UP(nentries, 64) / 8;
/*
* Migration compatibility dictates that this remains a 4k
--
MST
