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[Qemu-devel] [PULL 6/6] hw/virtio/balloon: Replace TARGET_PAGE_SIZE with
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 6/6] hw/virtio/balloon: Replace TARGET_PAGE_SIZE with BALLOON_PAGE_SIZE |
Date: |
Thu, 14 Apr 2016 16:48:19 +0300 |
From: Thomas Huth <address@hidden>
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 <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
hw/virtio/virtio-balloon.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index c74101e..9dbe681 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
--
MST
- [Qemu-devel] [PULL 0/6] tpm, vhost, virtio: fixes for 2.6, Michael S. Tsirkin, 2016/04/14
- [Qemu-devel] [PULL 1/6] specs/vhost-user: improve VHOST_SET_VRING_NUM documentation, Michael S. Tsirkin, 2016/04/14
- [Qemu-devel] [PULL 2/6] specs/vhost-user: spelling fix, Michael S. Tsirkin, 2016/04/14
- [Qemu-devel] [PULL 4/6] tpm: acpi: remove IRQ from TPM's CRS to make Windows not see conflict, Michael S. Tsirkin, 2016/04/14
- [Qemu-devel] [PULL 3/6] pc: acpi: tpm: add missing MMIO resource to PCI0._CRS, Michael S. Tsirkin, 2016/04/14
- [Qemu-devel] [PULL 5/6] tpm: Fix write to file descriptor function, Michael S. Tsirkin, 2016/04/14
- [Qemu-devel] [PULL 6/6] hw/virtio/balloon: Replace TARGET_PAGE_SIZE with BALLOON_PAGE_SIZE,
Michael S. Tsirkin <=
- Re: [Qemu-devel] [PULL 0/6] tpm, vhost, virtio: fixes for 2.6, Peter Maydell, 2016/04/14