On Fri, Jun 19, 2015 at 08:49:00AM +0200, Markus Armbruster wrote: > David Gibson <da...@gibson.dropbear.id.au> writes: > > > On Thu, Jun 18, 2015 at 09:35:44PM +1000, Alexey Kardashevskiy wrote: > >> On 05/05/2015 10:49 PM, David Gibson wrote: > >> >On Sat, Apr 25, 2015 at 10:24:43PM +1000, Alexey Kardashevskiy wrote: > >> >>This adds support for Dynamic DMA Windows (DDW) option defined by > >> >>the SPAPR specification which allows to have additional DMA window(s) > >> >> > >> >>This implements DDW for emulated and VFIO devices. As all TCE root > >> >>regions > >> >>are mapped at 0 and 64bit long (and actual tables are child regions), > >> >>this replaces memory_region_add_subregion() with _overlap() to make > >> >>QEMU memory API happy. > >> >> > >> >>This reserves RTAS token numbers for DDW calls. > >> >> > >> >>This implements helpers to interact with VFIO kernel interface. > >> >> > >> >>This changes the TCE table migration descriptor to support dynamic > >> >>tables as from now on, PHB will create as many stub TCE table objects > >> >>as PHB can possibly support but not all of them might be initialized at > >> >>the time of migration because DDW might or might not be requested by > >> >>the guest. > >> >> > >> >>The "ddw" property is enabled by default on a PHB but for compatibility > >> >>the pseries-2.3 machine and older disable it. > >> >> > >> >>This implements DDW for VFIO. The host kernel support is required. > >> >>This adds a "levels" property to PHB to control the number of levels > >> >>in the actual TCE table allocated by the host kernel, 0 is the default > >> >>value to tell QEMU to calculate the correct value. Current hardware > >> >>supports up to 5 levels. > >> >> > >> >>The existing linux guests try creating one additional huge DMA window > >> >>with 64K or 16MB pages and map the entire guest RAM to. If succeeded, > >> >>the guest switches to dma_direct_ops and never calls TCE hypercalls > >> >>(H_PUT_TCE,...) again. This enables VFIO devices to use the entire RAM > >> >>and not waste time on map/unmap later. > >> >> > >> >>This adds 4 RTAS handlers: > >> >>* ibm,query-pe-dma-window > >> >>* ibm,create-pe-dma-window > >> >>* ibm,remove-pe-dma-window > >> >>* ibm,reset-pe-dma-window > >> >>These are registered from type_init() callback. > >> >> > >> >>These RTAS handlers are implemented in a separate file to avoid polluting > >> >>spapr_iommu.c with PCI. > >> >> > >> >>Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > >> > > >> >Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> > >> > >> I saw this and decided there are no more coments but I was wrong :) > > > > Right. Note that if I add a Reviewed-by but also make comments, then > > those comments are seeking clarification and maybe suggesting later > > cleanups, but I think the problems are small enough that the patch is > > still ready to go as it is. > > You can help the recipient of your comments by putting your R-by behind > the last comment.
Noted for future reference. > Wouldn't be necessary if people never left reams of quoted material > at the end of their replies, but that's a pipe dream :) I do usually try to trim quoted material - looks like I forgot this time though. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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