[Xen-changelog] [qemu-upstream-unstable] kvm: fix incorrect length in a loop over kvm dirty pages map

[patchbot@xxxxxxx]

commit 752ced0488806830f18f96b60ae6f3d1fadfd089
Author: Alexey Kardashevskiy <aik@xxxxxxxxx>
Date:   Mon Nov 19 15:40:47 2012 +0000

    kvm: fix incorrect length in a loop over kvm dirty pages map
    
    QEMU allocates a map enough for 4k pages. However the system page size
    can be 64K (for example on POWER) and the host kernel uses only a small
    part of it as one big stores a dirty flag for 16 pages 4K each,
    the hpratio variable stores this ratio and
    the kvm_get_dirty_pages_log_range function handles it correctly.
    
    However kvm_get_dirty_pages_log_range still goes beyond the data
    provided by the host kernel which is not correct. It does not cause
    errors at the moment as the whole bitmap is zeroed before doing KVM ioctl.
    
    The patch reduces number of iterations over the map.
    
    Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
    Signed-off-by: Alexander Graf <agraf@xxxxxxx>
---
 kvm-all.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 3bc3347..8e9a8d8 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -364,7 +364,7 @@ static int 
kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
     unsigned int i, j;
     unsigned long page_number, c;
     hwaddr addr, addr1;
-    unsigned int len = ((section->size / TARGET_PAGE_SIZE) + HOST_LONG_BITS - 
1) / HOST_LONG_BITS;
+    unsigned int len = ((section->size / getpagesize()) + HOST_LONG_BITS - 1) 
/ HOST_LONG_BITS;
     unsigned long hpratio = getpagesize() / TARGET_PAGE_SIZE;
 
     /*
--
generated by git-patchbot for /home/xen/git/qemu-upstream-unstable.git

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