Re: [Xen-devel] kexec-ed kernel possibly needing low memory

2014-11-14 Thread Konrad Rzeszutek Wilk
On Fri, Nov 14, 2014 at 11:02:54AM +, David Vrabel wrote: > On 14/11/14 10:00, Jan Beulich wrote: > > David, > > > > we're being approached with the situation where a disk driver in the > > kexec-ed kernel needs memory below 4G in order to perform DMA > > (e.g. for the swiotlb to be set up). L

Re: [Xen-devel] kexec-ed kernel possibly needing low memory

2014-11-14 Thread David Vrabel
On 14/11/14 10:00, Jan Beulich wrote: > David, > > we're being approached with the situation where a disk driver in the > kexec-ed kernel needs memory below 4G in order to perform DMA > (e.g. for the swiotlb to be set up). Linux not so long ago invented a > two area approach, which doesn't fit wit