Re: [Qemu-devel] GSoC: Improved image format compatibility

[Lyu Mitnick]

Hello Stefan,

Let me summarize the ideas of "Improved image format compatibility"  now:

(1) add support of "Fixed hard disk image" into block/vpc.c

(2) add support of "Differencing hard disk image" into block/vpc.c

(3) add asynchronous i/o into block/vpc,c

(4) have some optimization of block/vpc.c

Would you mind to tell me the project containing four topics above is suitable for GSoC of size and skill level??

And would anyone is interested in this project and being my mentor??

thanks very much

2011/3/31 Stefan Weil <address@hidden>

Am 30.03.2011 20:40, schrieb Lyu Mitnick:

Hello Stefan,

I have spent a whole night to trace the code of block/vpc.c and compare against the VHD specifications

(at http://www.microsoft.com/downloads/en/details.aspx?FamilyID=C2D03242-2FFB-48EF-A211-F0C44741109E&amp;displaylang=en <http://www.microsoft.com/downloads/en/details.aspx?FamilyID=C2D03242-2FFB-48EF-A211-F0C44741109E&amp;displaylang=en>).

It seems that there isn't Fixed hard disk image and Differencing hard disk image support now. I am wondering whether what I has
learned from tracing code is true or false? I also found some possibility of optimization in block/vpc.c. Should I contact mentor
assigned to this project in private or post the whole idea on the mailing list??

thanks very much

Mitnick

Hello Mitnick,

asynchronous i/o is also missing in block/vpc.c.

All newer block drivers support asynchronous reads and writes,
only some old drivers don't.

So adding asynchronous i/o to at least some of the old drivers
would improve their usability.

Look for "aio" in block/*.c to get a starting point.

Regards
Stefan (W.)