On Fri, Mar 03, 2017 at 11:32:55AM +0000, Daniel P. Berrange wrote: > When using a memory-backend object with prealloc turned on, QEMU > will memset() the first byte in every memory page to zero. While > this might have been acceptable for memory backends associated > with RAM, this corrupts application data for NVDIMMs. > > Instead of setting every page to zero, read the current byte > value and then just write that same value back, so we are not > corrupting the original data. Directly write the value instead > of memset()ing it, since there's no benefit to memset for a > single byte write. > > Signed-off-by: Daniel P. Berrange <[email protected]> > --- > > Changed in v3: > > - Mark the target of the write as volatile, instead of the intermedia > variable (Andrea) > > util/oslib-posix.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-)
Reviewed-by: Stefan Hajnoczi <[email protected]>
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