Ahh, I got it! Thanks. 2011/11/25 Paolo Bonzini <pbonz...@redhat.com>
> On 11/25/2011 08:26 AM, Mark Wu wrote: > >> 1. This patch aims to add 4k logical support for qemu running on a host >> with 4k logical block size, right? >> > > No, it adds support for 512b logical block sizes running on a host with 4k > logical block size and cache=none. This is suboptimal as it requires > bounce buffers, but it can happen with migration and until libvirt provides > a knob for the guest's logical block size. > > > For guest, we can use >> logical_block_size=4096 to achieve that even on a host with the >> logical_block_size of 512. Am I right? >> > > Yes. > > > 2. Can we just call bdrv_get_alignment in bdrv_open_common once and use >> the stored buffer_alignment for future usage instead of always >> calling bdrv_get_alignment in qemu_blockalign/qiov_is_**aligned. What's >> the benefit of the dynamic way? >> > > Yes, I think it's possible. > > Paolo >
