[Qemu-devel] [PATCH 3/4] memory: hoist coalesced MMIO flush

[Paolo Bonzini <pbonzini@redhat.com>]

No need to flush the coalesced MMIO buffer multiple times when combining
multiple accesses into one.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 memory.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/memory.c b/memory.c
index 1ade19c..495e693 100644
--- a/memory.c
+++ b/memory.c
@@ -401,9 +401,6 @@ static void memory_region_read_accessor(MemoryRegion *mr,
 {
     uint64_t tmp;
 
-    if (mr->flush_coalesced_mmio) {
-        qemu_flush_coalesced_mmio_buffer();
-    }
     tmp = mr->ops->read(mr->opaque, addr, size);
     trace_memory_region_ops_read(mr, addr, tmp, size);
     *value |= (tmp & mask) << shift;
@@ -432,9 +429,6 @@ static void memory_region_write_accessor(MemoryRegion *mr,
 {
     uint64_t tmp;
 
-    if (mr->flush_coalesced_mmio) {
-        qemu_flush_coalesced_mmio_buffer();
-    }
     tmp = (*value >> shift) & mask;
     trace_memory_region_ops_write(mr, addr, tmp, size);
     mr->ops->write(mr->opaque, addr, tmp, size);
@@ -965,6 +959,10 @@ static bool memory_region_dispatch_read(MemoryRegion *mr,
                                         uint64_t *pval,
                                         unsigned size)
 {
+    if (mr->flush_coalesced_mmio) {
+        qemu_flush_coalesced_mmio_buffer();
+    }
+
     if (!memory_region_access_valid(mr, addr, size, false)) {
         *pval = unassigned_mem_read(mr, addr, size);
         return true;
@@ -1013,6 +1011,10 @@ static bool memory_region_dispatch_write(MemoryRegion *mr,
                                          uint64_t data,
                                          unsigned size)
 {
+    if (mr->flush_coalesced_mmio) {
+        qemu_flush_coalesced_mmio_buffer();
+    }
+
     if (!memory_region_access_valid(mr, addr, size, true)) {
         unassigned_mem_write(mr, addr, data, size);
         return true;
-- 
1.8.4.2