Good day, I''m toying around with a kernel mode caching layer that, at the moment, crashes into the ground if the driver is called from kernel space. I''ve been toying around with pvops dom0 kernels in the 2.6.3x family with the understanding that their lack of xen-blkback module would lead to an automatic fallback to a userspace blockdevice backend. Is there a secret switch to Xen 4.0/4.1 I need to be aware of to make this magic happen? Or is this a missing feature and does every pvops dom0-kernel that is not 3.0.1 need backports for xen-blkback? Cheers, Pim van Riezen _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Thu, Aug 11, 2011 at 02:53:47PM +0200, Pim van Riezen wrote:> Good day, > > I''m toying around with a kernel mode caching layer that, at the moment, > crashes into the ground if the driver is called from kernel space. > I''ve been toying around with pvops dom0 kernels in the 2.6.3x family > with the understanding that their lack of xen-blkback module would lead > to an automatic fallback to a userspace blockdevice backend. >Which exact 2.6.3x kernels/branches are you using? Jeremy''s xen.git xen/stable-2.6.32.x branch definitely does have a xen-blkback driver included.> Is there a secret switch to Xen 4.0/4.1 I need to be aware of to make this magic happen? Or is this a missing feature and does every pvops dom0-kernel that is not 3.0.1 need backports for xen-blkback? >Xen 4.0 won''t work, but afaik Xen 4.1 should fallback to qemu/userspace block backend if kernel xen-blkback is not available. -- Pasi _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Hi, On Aug 12, 2011, at 18:21 , Pasi Kärkkäinen wrote:> Which exact 2.6.3x kernels/branches are you using?I tried vanilla 2.6.39.4. Obviously xen-specific git trees will have xen-blkback. And 3.0.1 vanilla has it.> Jeremy''s xen.git xen/stable-2.6.32.x branch definitely does have a xen-blkback driver included.Yeah, found that one. Thanks.>> Is there a secret switch to Xen 4.0/4.1 I need to be aware of to make this magic happen? Or is this a missing feature and does every pvops dom0-kernel that is not 3.0.1 need backports for xen-blkback? >> > > Xen 4.0 won''t work, but afaik Xen 4.1 should fallback to qemu/userspace block backend if kernel xen-blkback is not available.Ah, perhaps I''m an idiot and didn''t retest with a kernel with no blkback once I upgraded to 4.1. Thanks. Cheers, Pim _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel