diff options
| author | Thomas Huth <thuth@redhat.com> | 2016-04-14 10:50:07 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2016-04-14 16:44:42 +0300 |
| commit | 01310e2aa7ad87f101d56feb8c06898084c9b542 (patch) | |
| tree | ab7ec099d14f3209d276896a08d0d465f5f36882 | |
| parent | e7658fcc4c29a29c578acde26f7714023b93b46e (diff) | |
hw/virtio/balloon: Replace TARGET_PAGE_SIZE with BALLOON_PAGE_SIZE
The balloon code currently calls madvise() with TARGET_PAGE_SIZE as
length parameter. Since the virtio-balloon protocol is always based
on 4k pages, no matter what the host and guest are using as page size,
this could cause problems: If TARGET_PAGE_SIZE is bigger than 4k, the
madvise call also destroys the 4k areas after the current one - which
might be wrong since the guest did not want free that area yet (in
case the guest used as smaller MMU page size than the hard-coded
TARGET_PAGE_SIZE). So to fix this issue, introduce a proper define
called BALLOON_PAGE_SIZE (which is 4096) to use this as the size
parameter for the madvise() call instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | hw/virtio/virtio-balloon.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index c74101e479..9dbe681790 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -19,7 +19,6 @@ #include "qemu-common.h" #include "hw/virtio/virtio.h" #include "hw/i386/pc.h" -#include "cpu.h" #include "sysemu/balloon.h" #include "hw/virtio/virtio-balloon.h" #include "sysemu/kvm.h" @@ -35,12 +34,14 @@ #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" +#define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT) + static void balloon_page(void *addr, int deflate) { #if defined(__linux__) if (!qemu_balloon_is_inhibited() && (!kvm_enabled() || kvm_has_sync_mmu())) { - qemu_madvise(addr, TARGET_PAGE_SIZE, + qemu_madvise(addr, BALLOON_PAGE_SIZE, deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED); } #endif |