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. Wouldn't be necessary if people never left reams of quoted material at the end of their replies, but that's a pipe dream :) [...]