Re: [RFC][PATCH 1/6] HVM PCI Passthrough (non-IOMMU)

[Muli Ben-Yehuda <muli@il.ibm.com>]

On Thu, May 31, 2007 at 07:04:40PM -0400, Guy Zana wrote:
> conf.patch:
> 
>     - Compile in x86_32 (disable PAE)
>     - Additional compilation switches (found in Config.mk):
>       mapping_1to1 - enables the 1:1 layout that allows DMA
>       passthrough  - enables non-IOMMU pass-through
> 
> Signed-off-by: Guy Zana <guy@neocleus.com>
> 
> --- a/Config.mk	Sat May 05 13:48:05 2007 +0100
> +++ b/Config.mk	Thu May 31 21:05:07 2007 +0300
> @@ -1,7 +1,11 @@
>  # -*- mode: Makefile; -*-
>  
>  # A debug build of Xen and tools?
> -debug ?= n
> +debug ?= n 

Whitespace damage.

> +
> +# PCI pass-through flags 
> +mapping_1to1 ?= y
> +passthrough ?= y

Does one make sense without the other?


>  XEN_COMPILE_ARCH    ?= $(shell uname -m | sed -e s/i.86/x86_32/ \
>                           -e s/ppc/powerpc/ -e s/i86pc/x86_32/)
> @@ -9,7 +13,7 @@ XEN_OS              ?= $(shell uname -s)
>  XEN_OS              ?= $(shell uname -s)
>  
>  ifeq ($(XEN_TARGET_ARCH),x86_32)
> -XEN_TARGET_X86_PAE  ?= y
> +XEN_TARGET_X86_PAE  ?= n 

Is there a dependency between 1-1 / passthrough and !PAE, or is this
just for convenience?

>  endif
>  
>  CONFIG_$(XEN_OS) := y
> --- a/tools/Rules.mk	Sat May 05 13:48:05 2007 +0100
> +++ b/tools/Rules.mk	Thu May 31 21:04:53 2007 +0300
> @@ -13,6 +13,14 @@ X11_LDPATH = -L/usr/X11R6/$(LIBDIR)
>  X11_LDPATH = -L/usr/X11R6/$(LIBDIR)
>  
>  CFLAGS += -D__XEN_TOOLS__
> +
> +ifeq ($(passthrough),y)
> +    CFLAGS += -DCONFIG_NEO
> +endif

You probably want a better name than CONFIG_NEO, much to the
disappointment of matrix fans everywhere.

> +
> +ifeq ($(mapping_1to1),y)
> +    CFLAGS += -DCONFIG_1TO1
> +endif
>  
>  # Enable implicit LFS support *and* explicit LFS names.
>  CFLAGS  += $(shell getconf LFS_CFLAGS)
> --- a/xen/Rules.mk	Sat May 05 13:48:05 2007 +0100
> +++ b/xen/Rules.mk	Thu May 31 21:04:53 2007 +0300
> @@ -50,12 +50,16 @@ ALL_OBJS-$(ACM_SECURITY) += $(BASEDIR)/a
>  ALL_OBJS-$(ACM_SECURITY) += $(BASEDIR)/acm/built_in.o
>  ALL_OBJS-y               += $(BASEDIR)/arch/$(TARGET_ARCH)/built_in.o
>  
> -CFLAGS-y               += -g -D__XEN__
> -CFLAGS-$(ACM_SECURITY) += -DACM_SECURITY
> -CFLAGS-$(verbose)      += -DVERBOSE
> -CFLAGS-$(crash_debug)  += -DCRASH_DEBUG
> -CFLAGS-$(perfc)        += -DPERF_COUNTERS
> -CFLAGS-$(perfc_arrays) += -DPERF_ARRAYS
> +CFLAGS-y                        += -g -D__XEN__
> +# NEO stuff
> +CFLAGS-$(passthrough)           += -DCONFIG_NEO
> +CFLAGS-$(mapping_1to1)          += -DCONFIG_1TO1
> +
> +CFLAGS-$(ACM_SECURITY)          += -DACM_SECURITY
> +CFLAGS-$(verbose)               += -DVERBOSE
> +CFLAGS-$(crash_debug)           += -DCRASH_DEBUG
> +CFLAGS-$(perfc)                 += -DPERF_COUNTERS
> +CFLAGS-$(perfc_arrays)          += -DPERF_ARRAYS

This should be changed to only touch the new bits, makes it easier to
review.

Cheers,
Muli