From: Andre Przywara <andre.przywara@arm.com>
To: Will Deacon <Will.Deacon@arm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Matt Evans <matt@ozlabs.org>
Cc: "kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Subject: Re: [PATCH 2/3] powerpc: use default endianness for converting guest/init
Date: Thu, 18 Jun 2015 14:52:06 +0000 [thread overview]
Message-ID: <5582DB16.8060808@arm.com> (raw)
In-Reply-To: <1434534230-17249-3-git-send-email-andre.przywara@arm.com>
Hi,
On 06/17/2015 10:43 AM, Andre Przywara wrote:
> For converting the guest/init binary into an object file, we call
> the linker binary, setting the endianness to big endian explicitly
> when compiling kvmtool for powerpc.
> This breaks if the compiler is actually targetting little endian
> (which is true for the Debian port, for instance).
> Remove the explicit big endianness switch from the linker call to
> allow linking on little endian PowerPC builds again.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> Hi,
>
> this fixed the powerpc64le build for me, while still compiling fine
> for big endian. Admittedly this whole init->guest_init.o conversion
> has its issues (with MIPS, for instance), which deserve proper fixing,
> but lets just fix that build for now.
>
Will was concerned about breaking toolchains where the linker does not
default to 64-bit. Is that an issue we care about?
AFAICT LDFLAGS is only used in this dodgy binary-to-object-file
conversion of guest/init. For this we rely on the resulting .o file to
have the same ELF target as the other object files to be finally linked
into the lkvm binary. As we don't compile guest/init with CFLAGS, there
is a possible mismatch.
I am looking into a proper fix for this now (compiling guest/init with
CFLAGS, calling $CC with linker options instead of $LD and allowing CC
and LD override). Still struggling with MIPS, though :-(
If someone is eager to fix compilation on PowerPC meanwhile, feel free
to use this fix for the time being.
Cheers,
Andre.
>
> Makefile | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index 6110b8e..c118e1a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -149,7 +149,6 @@ ifeq ($(ARCH), powerpc)
> OBJS += powerpc/xics.o
> ARCH_INCLUDE := powerpc/include
> CFLAGS += -m64
> - LDFLAGS += -m elf64ppc
>
> ARCH_WANT_LIBFDT := y
> endif
>
WARNING: multiple messages have this Message-ID (diff)
From: Andre Przywara <andre.przywara@arm.com>
To: Will Deacon <Will.Deacon@arm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Matt Evans <matt@ozlabs.org>
Cc: "kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Subject: Re: [PATCH 2/3] powerpc: use default endianness for converting guest/init
Date: Thu, 18 Jun 2015 15:52:06 +0100 [thread overview]
Message-ID: <5582DB16.8060808@arm.com> (raw)
In-Reply-To: <1434534230-17249-3-git-send-email-andre.przywara@arm.com>
Hi,
On 06/17/2015 10:43 AM, Andre Przywara wrote:
> For converting the guest/init binary into an object file, we call
> the linker binary, setting the endianness to big endian explicitly
> when compiling kvmtool for powerpc.
> This breaks if the compiler is actually targetting little endian
> (which is true for the Debian port, for instance).
> Remove the explicit big endianness switch from the linker call to
> allow linking on little endian PowerPC builds again.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> Hi,
>
> this fixed the powerpc64le build for me, while still compiling fine
> for big endian. Admittedly this whole init->guest_init.o conversion
> has its issues (with MIPS, for instance), which deserve proper fixing,
> but lets just fix that build for now.
>
Will was concerned about breaking toolchains where the linker does not
default to 64-bit. Is that an issue we care about?
AFAICT LDFLAGS is only used in this dodgy binary-to-object-file
conversion of guest/init. For this we rely on the resulting .o file to
have the same ELF target as the other object files to be finally linked
into the lkvm binary. As we don't compile guest/init with CFLAGS, there
is a possible mismatch.
I am looking into a proper fix for this now (compiling guest/init with
CFLAGS, calling $CC with linker options instead of $LD and allowing CC
and LD override). Still struggling with MIPS, though :-(
If someone is eager to fix compilation on PowerPC meanwhile, feel free
to use this fix for the time being.
Cheers,
Andre.
>
> Makefile | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index 6110b8e..c118e1a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -149,7 +149,6 @@ ifeq ($(ARCH), powerpc)
> OBJS += powerpc/xics.o
> ARCH_INCLUDE := powerpc/include
> CFLAGS += -m64
> - LDFLAGS += -m elf64ppc
>
> ARCH_WANT_LIBFDT := y
> endif
>
next prev parent reply other threads:[~2015-06-18 14:52 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-17 9:43 [PATCH 0/3] kvmtool: fixes for PowerPC Andre Przywara
2015-06-17 9:43 ` Andre Przywara
2015-06-17 9:43 ` [PATCH 1/3] powerpc: implement barrier primitives Andre Przywara
2015-06-17 9:43 ` Andre Przywara
2015-06-17 10:15 ` Will Deacon
2015-06-17 10:15 ` Will Deacon
2015-06-17 10:46 ` Alexander Graf
2015-06-17 10:46 ` Alexander Graf
2015-06-18 9:11 ` Michael Ellerman
2015-06-18 9:11 ` Michael Ellerman
2015-06-18 9:38 ` Will Deacon
2015-06-18 9:38 ` Will Deacon
2015-06-17 9:43 ` [PATCH 2/3] powerpc: use default endianness for converting guest/init Andre Przywara
2015-06-17 9:43 ` Andre Przywara
2015-06-18 14:52 ` Andre Przywara [this message]
2015-06-18 14:52 ` Andre Przywara
2015-06-19 1:08 ` Michael Ellerman
2015-06-19 1:08 ` Michael Ellerman
2015-06-19 16:15 ` Andre Przywara
2015-06-19 16:15 ` Andre Przywara
2015-06-21 20:01 ` Michael Ellerman
2015-06-21 20:01 ` Michael Ellerman
2015-06-17 9:43 ` [PATCH 3/3] powerpc: add hvcall.h header from Linux Andre Przywara
2015-06-17 9:43 ` Andre Przywara
2015-06-17 10:13 ` Will Deacon
2015-06-17 10:13 ` Will Deacon
2015-06-18 9:15 ` Michael Ellerman
2015-06-18 9:15 ` Michael Ellerman
2015-06-18 10:10 ` [PATCH v2] " Andre Przywara
2015-06-18 10:10 ` Andre Przywara
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