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author | Paolo Bonzini <pbonzini@redhat.com> | 2011-11-29 12:42:20 +0100 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2014-01-24 17:40:02 +0100 |
commit | c25f53b06eba1575d5d0e92a0132455c97825b83 (patch) | |
tree | cf2b0c8ed726159431608cf097f9c89d022104aa /block.c | |
parent | 1b7fd729559c6d3b273303aa48bc653ceef08747 (diff) | |
download | qemu-c25f53b06eba1575d5d0e92a0132455c97825b83.zip qemu-c25f53b06eba1575d5d0e92a0132455c97825b83.tar.gz qemu-c25f53b06eba1575d5d0e92a0132455c97825b83.tar.bz2 |
raw: Probe required direct I/O alignment
Add a bs->request_alignment field that contains the required
offset/length alignment for I/O requests and fill it in the raw block
drivers. Use ioctls if possible, else see what alignment it takes for
O_DIRECT to succeed.
While at it, also expose the memory alignment requirements, which may be
(and in practice are) different from the disk alignment requirements.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block.c')
-rw-r--r-- | block.c | 3 |
1 files changed, 3 insertions, 0 deletions
@@ -852,6 +852,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, bs->open_flags = flags; bs->guest_block_size = 512; + bs->request_alignment = 512; bs->zero_beyond_eof = true; open_flags = bdrv_open_flags(bs, flags); bs->read_only = !(open_flags & BDRV_O_RDWR); @@ -920,6 +921,8 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, } bdrv_refresh_limits(bs); + assert(bdrv_opt_mem_align(bs) != 0); + assert(bs->request_alignment != 0); #ifndef _WIN32 if (bs->is_temporary) { |