Re: [Qemu-devel] [PATCH 2/2] Add AT24Cxx I2C EEPROM device model

[Stefan Hajnoczi]

On Mon, Nov 19, 2012 at 03:24:39PM +0100, Jan Kiszka wrote:
> +static void at24_flush_transfer_buffer(AT24State *s)
> +{
> +    if (s->cached_sector < 0 || !s->cache_dirty) {
> +        return;
> +    }
> +    bdrv_write(s->bs, s->cached_sector, s->sector_buffer, 1);
[...]
> +static int at24_cache_sector(AT24State *s, int sector)
> +{
> +    int ret;
> +
> +    if (s->cached_sector == sector) {
> +        return 0;
> +    }
> +    ret = bdrv_read(s->bs, sector, s->sector_buffer, 1);

Can you use bdrv_aio_writev()/bdrv_aio_readv()?  We should avoid adding
new synchronous block I/O.  Because it forces us to run a nested event
loop that blocks the guest until I/O completes.

Stefan