Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* device_del fix (Julia)
* FXAM fix (myself)
* memdev refactoring (Igor)
* memory region API cleanups (Peter, Philippe)
* ioeventfd optimization (Stefan)
* new WHPX maintainer (Sunil)
* Large guest startup optimizations (Chen)

# gpg: Signature made Tue 25 Feb 2020 12:42:24 GMT
# gpg:                using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (104 commits)
  WHPX: Assigning maintainer for Windows Hypervisor Platform
  accel/kvm: Check ioctl(KVM_SET_USER_MEMORY_REGION) return value
  target/i386: check for empty register in FXAM
  qdev-monitor: Forbid repeated device_del
  mem-prealloc: optimize large guest startup
  memory: batch allocate ioeventfds[] in address_space_update_ioeventfds()
  Avoid cpu_physical_memory_rw() with a constant is_write argument
  Let cpu_[physical]_memory() calls pass a boolean 'is_write' argument
  exec: Let cpu_[physical]_memory API use a boolean 'is_write' argument
  Avoid address_space_rw() with a constant is_write argument
  Let address_space_rw() calls pass a boolean 'is_write' argument
  exec: Let address_space_unmap() use a boolean 'is_write' argument
  hw/virtio: Let vhost_memory_map() use a boolean 'is_write' argument
  hw/virtio: Let virtqueue_map_iovec() use a boolean 'is_write' argument
  hw/ide: Let the DMAIntFunc prototype use a boolean 'is_write' argument
  hw/ide/internal: Remove unused DMARestartFunc typedef
  Remove unnecessary cast when using the cpu_[physical]_memory API
  exec: Let the cpu_[physical]_memory API use void pointer arguments
  Remove unnecessary cast when using the address_space API
  hw/net: Avoid casting non-const pointer, use address_space_write()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 15 insertions, 3 deletions

diff --git a/memory.c b/memory.c
index aeaa8dcc9e..09be40edd2 100644
--- a/memory.c
+++ b/memory.c
@@ -794,10 +794,19 @@ static void address_space_update_ioeventfds(AddressSpace *as)
     FlatView *view;
     FlatRange *fr;
     unsigned ioeventfd_nb = 0;
-    MemoryRegionIoeventfd *ioeventfds = NULL;
+    unsigned ioeventfd_max;
+    MemoryRegionIoeventfd *ioeventfds;
     AddrRange tmp;
     unsigned i;
 
+    /*
+     * It is likely that the number of ioeventfds hasn't changed much, so use
+     * the previous size as the starting value, with some headroom to avoid
+     * gratuitous reallocations.
+     */
+    ioeventfd_max = QEMU_ALIGN_UP(as->ioeventfd_nb, 4);
+    ioeventfds = g_new(MemoryRegionIoeventfd, ioeventfd_max);
+
     view = address_space_get_flatview(as);
     FOR_EACH_FLAT_RANGE(fr, view) {
         for (i = 0; i < fr->mr->ioeventfd_nb; ++i) {
@@ -806,8 +815,11 @@ static void address_space_update_ioeventfds(AddressSpace *as)
                                              int128_make64(fr->offset_in_region)));
             if (addrrange_intersects(fr->addr, tmp)) {
                 ++ioeventfd_nb;
-                ioeventfds = g_realloc(ioeventfds,
-                                          ioeventfd_nb * sizeof(*ioeventfds));
+                if (ioeventfd_nb > ioeventfd_max) {
+                    ioeventfd_max = MAX(ioeventfd_max * 2, 4);
+                    ioeventfds = g_realloc(ioeventfds,
+                            ioeventfd_max * sizeof(*ioeventfds));
+                }
                 ioeventfds[ioeventfd_nb-1] = fr->mr->ioeventfds[i];
                 ioeventfds[ioeventfd_nb-1].addr = tmp;
             }