[Qemu-devel] [PATCH 0/3] memory: update coalesced_range on transaction_commit

[Qemu-devel] [PATCH 0/3] memory: update coalesced_range on transaction_commit

[Paolo Bonzini]

The e1000 driver calls memory_region_add_coalescing but
kvm_coalesce_mmio_region is never called for those regions.  The bug
dates back to the introduction of the memory region API; to fix it,
the last patch deletes and re-adds coalesced MMIO ranges when building
the FlatViews.  The first two patches are preparatory changes.

Paolo Bonzini (3):
  memory: extract flat_range_coalesced_io_{del,add}
  memory: avoid unnecessary coalesced_io_del operations
  memory: update coalesced_range on transaction_commit

 memory.c | 78 ++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 53 insertions(+), 25 deletions(-)

-- 
2.19.1

[Qemu-devel] [PATCH 1/3] memory: extract flat_range_coalesced_io_{del, add}

[Paolo Bonzini]

Extract two new functions from memory_region_update_coalesced_range_as.
To avoid duplication in the creation of the MemoryRegionSection, use
MEMORY_LISTENER_UPDATE_REGION instead of MEMORY_LISTENER_CALL
to invoke the listener callback.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 memory.c | 53 +++++++++++++++++++++++++++++------------------------
 1 file changed, 29 insertions(+), 24 deletions(-)

diff --git a/memory.c b/memory.c
index d14c6dec1d..119b6e46d5 100644
--- a/memory.c
+++ b/memory.c
@@ -850,6 +850,33 @@ static void address_space_update_ioeventfds(AddressSpace *as)
     flatview_unref(view);
 }
 
+static void flat_range_coalesced_io_del(FlatRange *fr, AddressSpace *as)
+{
+    MEMORY_LISTENER_UPDATE_REGION(fr, as, Reverse, coalesced_io_del,
+                                  int128_get64(fr->addr.start),
+                                  int128_get64(fr->addr.size));
+}
+
+static void flat_range_coalesced_io_add(FlatRange *fr, AddressSpace *as)
+{
+    MemoryRegion *mr = fr->mr;
+    CoalescedMemoryRange *cmr;
+    AddrRange tmp;
+
+    QTAILQ_FOREACH(cmr, &mr->coalesced, link) {
+        tmp = addrrange_shift(cmr->addr,
+                              int128_sub(fr->addr.start,
+                                         int128_make64(fr->offset_in_region)));
+        if (!addrrange_intersects(tmp, fr->addr)) {
+            continue;
+        }
+        tmp = addrrange_intersection(tmp, fr->addr);
+        MEMORY_LISTENER_UPDATE_REGION(fr, as, Forward, coalesced_io_add,
+                                      int128_get64(tmp.start),
+                                      int128_get64(tmp.size));
+    }
+}
+
 static void address_space_update_topology_pass(AddressSpace *as,
                                                const FlatView *old_view,
                                                const FlatView *new_view,
@@ -2136,34 +2163,12 @@ static void memory_region_update_coalesced_range_as(MemoryRegion *mr, AddressSpa
 {
     FlatView *view;
     FlatRange *fr;
-    CoalescedMemoryRange *cmr;
-    AddrRange tmp;
-    MemoryRegionSection section;
 
     view = address_space_get_flatview(as);
     FOR_EACH_FLAT_RANGE(fr, view) {
         if (fr->mr == mr) {
-            section = (MemoryRegionSection) {
-                .fv = view,
-                .offset_within_address_space = int128_get64(fr->addr.start),
-                .size = fr->addr.size,
-            };
-
-            MEMORY_LISTENER_CALL(as, coalesced_io_del, Reverse, &section,
-                                 int128_get64(fr->addr.start),
-                                 int128_get64(fr->addr.size));
-            QTAILQ_FOREACH(cmr, &mr->coalesced, link) {
-                tmp = addrrange_shift(cmr->addr,
-                                      int128_sub(fr->addr.start,
-                                                 int128_make64(fr->offset_in_region)));
-                if (!addrrange_intersects(tmp, fr->addr)) {
-                    continue;
-                }
-                tmp = addrrange_intersection(tmp, fr->addr);
-                MEMORY_LISTENER_CALL(as, coalesced_io_add, Forward, &section,
-                                     int128_get64(tmp.start),
-                                     int128_get64(tmp.size));
-            }
+            flat_range_coalesced_io_del(fr, as);
+            flat_range_coalesced_io_add(fr, as);
         }
     }
     flatview_unref(view);
-- 
2.19.1

[Qemu-devel] [PATCH 2/3] memory: avoid unnecessary coalesced_io_del operations

[Paolo Bonzini]

Store whether the FlatRange has had any coalesced I/O ranges applied,
and if not avoid calling coalesced_io_del.  This is useful in preparation
for the next patch, which will call coalesced_io_del when rendering
memory regions.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 memory.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/memory.c b/memory.c
index 119b6e46d5..072769aa06 100644
--- a/memory.c
+++ b/memory.c
@@ -217,6 +217,7 @@ struct FlatRange {
     bool romd_mode;
     bool readonly;
     bool nonvolatile;
+    bool has_coalesced_range;
 };
 
 #define FOR_EACH_FLAT_RANGE(var, view)          \
@@ -650,6 +651,7 @@ static void render_memory_region(FlatView *view,
     fr.romd_mode = mr->romd_mode;
     fr.readonly = readonly;
     fr.nonvolatile = nonvolatile;
+    fr.has_coalesced_range = false;
 
     /* Render the region itself into any gaps left by the current view. */
     for (i = 0; i < view->nr && int128_nz(remain); ++i) {
@@ -852,6 +854,10 @@ static void address_space_update_ioeventfds(AddressSpace *as)
 
 static void flat_range_coalesced_io_del(FlatRange *fr, AddressSpace *as)
 {
+    if (!fr->has_coalesced_range) {
+        return;
+    }
+
     MEMORY_LISTENER_UPDATE_REGION(fr, as, Reverse, coalesced_io_del,
                                   int128_get64(fr->addr.start),
                                   int128_get64(fr->addr.size));
@@ -863,6 +869,11 @@ static void flat_range_coalesced_io_add(FlatRange *fr, AddressSpace *as)
     CoalescedMemoryRange *cmr;
     AddrRange tmp;
 
+    if (QTAILQ_EMPTY(&mr->coalesced)) {
+        return;
+    }
+
+    fr->has_coalesced_range = true;
     QTAILQ_FOREACH(cmr, &mr->coalesced, link) {
         tmp = addrrange_shift(cmr->addr,
                               int128_sub(fr->addr.start,
-- 
2.19.1

[Qemu-devel] [PATCH 3/3] memory: update coalesced_range on transaction_commit

[Paolo Bonzini]

The e1000 driver calls memory_region_add_coalescing but
kvm_coalesce_mmio_region is never called for those regions.  The bug
dates back to the introduction of the memory region API; to fix it,
delete and re-add coalesced MMIO ranges when building the FlatViews.

Because coalesced MMIO regions apply to all address spaces, the
has_coalesced_range flag has to be changed into an int.

Fixes: 093bc2cd885e ("Hierarchical memory region API")
Reported-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Tested-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 memory.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/memory.c b/memory.c
index 072769aa06..5759f74034 100644
--- a/memory.c
+++ b/memory.c
@@ -217,7 +217,7 @@ struct FlatRange {
     bool romd_mode;
     bool readonly;
     bool nonvolatile;
-    bool has_coalesced_range;
+    int has_coalesced_range;
 };
 
 #define FOR_EACH_FLAT_RANGE(var, view)          \
@@ -651,7 +651,7 @@ static void render_memory_region(FlatView *view,
     fr.romd_mode = mr->romd_mode;
     fr.readonly = readonly;
     fr.nonvolatile = nonvolatile;
-    fr.has_coalesced_range = false;
+    fr.has_coalesced_range = 0;
 
     /* Render the region itself into any gaps left by the current view. */
     for (i = 0; i < view->nr && int128_nz(remain); ++i) {
@@ -858,6 +858,10 @@ static void flat_range_coalesced_io_del(FlatRange *fr, AddressSpace *as)
         return;
     }
 
+    if (--fr->has_coalesced_range > 0) {
+        return;
+    }
+
     MEMORY_LISTENER_UPDATE_REGION(fr, as, Reverse, coalesced_io_del,
                                   int128_get64(fr->addr.start),
                                   int128_get64(fr->addr.size));
@@ -873,7 +877,10 @@ static void flat_range_coalesced_io_add(FlatRange *fr, AddressSpace *as)
         return;
     }
 
-    fr->has_coalesced_range = true;
+    if (fr->has_coalesced_range++) {
+        return;
+    }
+
     QTAILQ_FOREACH(cmr, &mr->coalesced, link) {
         tmp = addrrange_shift(cmr->addr,
                               int128_sub(fr->addr.start,
@@ -920,6 +927,7 @@ static void address_space_update_topology_pass(AddressSpace *as,
             /* In old but not in new, or in both but attributes changed. */
 
             if (!adding) {
+                flat_range_coalesced_io_del(frold, as);
                 MEMORY_LISTENER_UPDATE_REGION(frold, as, Reverse, region_del);
             }
 
@@ -927,7 +935,9 @@ static void address_space_update_topology_pass(AddressSpace *as,
         } else if (frold && frnew && flatrange_equal(frold, frnew)) {
             /* In both and unchanged (except logging may have changed) */
 
-            if (adding) {
+            if (!adding) {
+                flat_range_coalesced_io_del(frold, as);
+            } else {
                 MEMORY_LISTENER_UPDATE_REGION(frnew, as, Forward, region_nop);
                 if (frnew->dirty_log_mask & ~frold->dirty_log_mask) {
                     MEMORY_LISTENER_UPDATE_REGION(frnew, as, Forward, log_start,
@@ -939,6 +949,7 @@ static void address_space_update_topology_pass(AddressSpace *as,
                                                   frold->dirty_log_mask,
                                                   frnew->dirty_log_mask);
                 }
+                flat_range_coalesced_io_add(frnew, as);
             }
 
             ++iold;
@@ -948,6 +959,7 @@ static void address_space_update_topology_pass(AddressSpace *as,
 
             if (adding) {
                 MEMORY_LISTENER_UPDATE_REGION(frnew, as, Forward, region_add);
+                flat_range_coalesced_io_add(frnew, as);
             }
 
             ++inew;
-- 
2.19.1