kvmtool : [PATCH] PowerPc : Fix compilation for ppc64

kvmtool : [PATCH] PowerPc : Fix compilation for ppc64

[Prerna Saxena]

'lkvm' compilation on ppc64 fails with the following error :
...[snip]..
  LINK     guest/init
  LINK     lkvm
/usr/bin/ld: powerpc:common architecture of input file `guest/guest_init.o'
is incompatible with powerpc:common64 output
collect2: ld returned 1 exit status
make: *** [lkvm] Error 1

This patch corrects the error above, and enables 'lkvm' to compile on ppc64
architecture.

Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
---
 tools/kvm/Makefile |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
index 0c59faa..269e29e 100644
--- a/tools/kvm/Makefile
+++ b/tools/kvm/Makefile
@@ -335,7 +335,11 @@ $(PROGRAM_ALIAS): $(PROGRAM)
 $(GUEST_INIT): guest/init.c
 	$(E) "  LINK    " $@
 	$(Q) $(CC) -static guest/init.c -o $@
+ifeq ($(ARCH), powerpc)
+	$(Q) $(LD) -r -b binary --oformat elf64-powerpc -o guest/guest_init.o $(GUEST_INIT)
+else
 	$(Q) $(LD) -r -b binary -o guest/guest_init.o $(GUEST_INIT)
+endif
 
 $(DEPS):
 
-- 
1.7.10.4



Regards,
-- 
Prerna Saxena

Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India

Re: kvmtool : [PATCH] PowerPc : Fix compilation for ppc64

[Pekka Enberg]

On Tue, Apr 9, 2013 at 8:29 PM, Prerna Saxena <prerna@linux.vnet.ibm.com> wrote:
> 'lkvm' compilation on ppc64 fails with the following error :
> ...[snip]..
>   LINK     guest/init
>   LINK     lkvm
> /usr/bin/ld: powerpc:common architecture of input file `guest/guest_init.o'
> is incompatible with powerpc:common64 output
> collect2: ld returned 1 exit status
> make: *** [lkvm] Error 1
>
> This patch corrects the error above, and enables 'lkvm' to compile on ppc64
> architecture.
>
> Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
> ---
>  tools/kvm/Makefile |    4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
> index 0c59faa..269e29e 100644
> --- a/tools/kvm/Makefile
> +++ b/tools/kvm/Makefile
> @@ -335,7 +335,11 @@ $(PROGRAM_ALIAS): $(PROGRAM)
>  $(GUEST_INIT): guest/init.c
>         $(E) "  LINK    " $@
>         $(Q) $(CC) -static guest/init.c -o $@
> +ifeq ($(ARCH), powerpc)
> +       $(Q) $(LD) -r -b binary --oformat elf64-powerpc -o guest/guest_init.o $(GUEST_INIT)
> +else
>         $(Q) $(LD) -r -b binary -o guest/guest_init.o $(GUEST_INIT)
> +endif
>
>  $(DEPS):
>
> --
> 1.7.10.4

Michael, Sasha, comments?

Re: kvmtool : [PATCH] PowerPc : Fix compilation for ppc64

[Prerna Saxena]

On 04/10/2013 09:05 PM, Sasha Levin wrote:
> Hm, what would LD create before this patch? I thought that the default
> would be to create a binary that corresponds to the platform you're
> building in, so if you build on ppc64 you'd get ppc64 binaries, no?
> 

Hi Sasha,
Thanks for the prompt response.
Powerpc had historically supported 32 bit userspace on a 64 bit kernel,
before everything moved 64 bit.

I'd hit this issue since the default output of 'ld' was turning out to
be 'elf32-powerpc' on my ppc64 build machine. This was running ld-2.22.
I found that adding '--oformat=elf64-powerpc' to the Makefile helped me
tide over it, so I sent a patch to that end.
Today, I verified on another ppc64 machine that ld is automatically
choosing 'elf64-powerpc'. This machine is running 'ld-2.23'

So, this patch can be ignored, since it appears to be a toolchain
dependency. Or, we could put it in place, to ensure kvmtool builds dont
break even if the toolchain is not perfectly configured.
As you suggest :)

Regards,
Prerna

> 
> 
> On Wed, Apr 10, 2013 at 2:44 AM, Pekka Enberg <penberg@kernel.org
> <mailto:penberg@kernel.org>> wrote:
> 
>     On Tue, Apr 9, 2013 at 8:29 PM, Prerna Saxena
>     <prerna@linux.vnet.ibm.com <mailto:prerna@linux.vnet.ibm.com>> wrote:
>     > 'lkvm' compilation on ppc64 fails with the following error :
>     > ...[snip]..
>     >   LINK     guest/init
>     >   LINK     lkvm
>     > /usr/bin/ld: powerpc:common architecture of input file
>     `guest/guest_init.o'
>     > is incompatible with powerpc:common64 output
>     > collect2: ld returned 1 exit status
>     > make: *** [lkvm] Error 1
>     >
>     > This patch corrects the error above, and enables 'lkvm' to compile
>     on ppc64
>     > architecture.
>     >
>     > Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com
>     <mailto:prerna@linux.vnet.ibm.com>>
>     > ---
>     >  tools/kvm/Makefile |    4 ++++
>     >  1 file changed, 4 insertions(+)
>     >
>     > diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
>     > index 0c59faa..269e29e 100644
>     > --- a/tools/kvm/Makefile
>     > +++ b/tools/kvm/Makefile
>     > @@ -335,7 +335,11 @@ $(PROGRAM_ALIAS): $(PROGRAM)
>     >  $(GUEST_INIT): guest/init.c
>     >         $(E) "  LINK    " $@
>     >         $(Q) $(CC) -static guest/init.c -o $@
>     > +ifeq ($(ARCH), powerpc)
>     > +       $(Q) $(LD) -r -b binary --oformat elf64-powerpc -o
>     guest/guest_init.o $(GUEST_INIT)
>     > +else
>     >         $(Q) $(LD) -r -b binary -o guest/guest_init.o $(GUEST_INIT)
>     > +endif
>     >
>     >  $(DEPS):
>     >
>     > --
>     > 1.7.10.4
> 
>     Michael, Sasha, comments?
>     --
>     To unsubscribe from this list: send the line "unsubscribe kvm" in
>     the body of a message to majordomo@vger.kernel.org
>     <mailto:majordomo@vger.kernel.org>
>     More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 


-- 
Prerna Saxena

Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India

Re: kvmtool : [PATCH] PowerPc : Fix compilation for ppc64

[Sasha Levin]

On 04/11/2013 12:53 PM, Prerna Saxena wrote:
> On 04/10/2013 09:05 PM, Sasha Levin wrote:
>> Hm, what would LD create before this patch? I thought that the default
>> would be to create a binary that corresponds to the platform you're
>> building in, so if you build on ppc64 you'd get ppc64 binaries, no?
>>
> 
> Hi Sasha,
> Thanks for the prompt response.
> Powerpc had historically supported 32 bit userspace on a 64 bit kernel,
> before everything moved 64 bit.
> 
> I'd hit this issue since the default output of 'ld' was turning out to
> be 'elf32-powerpc' on my ppc64 build machine. This was running ld-2.22.
> I found that adding '--oformat=elf64-powerpc' to the Makefile helped me
> tide over it, so I sent a patch to that end.
> Today, I verified on another ppc64 machine that ld is automatically
> choosing 'elf64-powerpc'. This machine is running 'ld-2.23'
> 
> So, this patch can be ignored, since it appears to be a toolchain
> dependency. Or, we could put it in place, to ensure kvmtool builds dont
> break even if the toolchain is not perfectly configured.
> As you suggest :)

What worries me with about this patch is that it will break build on 32bit
machines.

I don't know if those are even supported these days or not, but if they are -
we need something different to handle that.


Thanks,
Sasha