qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Re: [PATCH] qemu: make virtio-blk PCI compliant by defa


From: Anthony Liguori
Subject: Re: [Qemu-devel] Re: [PATCH] qemu: make virtio-blk PCI compliant by default
Date: Tue, 22 Sep 2009 20:59:02 -0500
User-agent: Thunderbird 2.0.0.23 (X11/20090825)

john cooper wrote:
Avi Kivity wrote:
On 09/22/2009 05:21 PM, john cooper wrote:
Can we just read this page as a virtqueue command instead of having it
mapped permanently?
Probably although I hadn't looked specifically
at doing so.   Mapping the data via an unused
pci bar is pretty trivial and seemed minimally
intrusive to the existing driver.
We'll run out of bars if we expend them like that.

Agreed.  However my motivation here was to use a
single additional bar specifically to compensate
for the PCI spec imposed 256 byte size limitation
of the config space mapping.  As we're defining the
content/size of this area, future use to accommodate
additional data should be unrestricted.

Why expose the whole ATAPI page instead of just the serial number?

I think the proper solution is to move the config to a separate bar that's MMIO instead of PIO. config access is never performance sensitive and an MMIO bar has less restrictions on size.

Regards,

Anthony Liguori




reply via email to

[Prev in Thread] Current Thread [Next in Thread]