Re: [PATCH v3 4/8] powerpc/pseries/svm: Add a powerpc version of cc_platform_has()

[Christophe Leroy]

Le 14/09/2021 à 13:58, Borislav Petkov a écrit :
> On Wed, Sep 08, 2021 at 05:58:35PM -0500, Tom Lendacky wrote:
> > Introduce a powerpc version of the cc_platform_has() function. This will
> > be used to replace the powerpc mem_encrypt_active() implementation, so
> > the implementation will initially only support the CC_ATTR_MEM_ENCRYPT
> > attribute.
> >
> > Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> > Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Paul Mackerras <paulus@xxxxxxxxx>
> > Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
> > ---
> >   arch/powerpc/platforms/pseries/Kconfig       |  1 +
> >   arch/powerpc/platforms/pseries/Makefile      |  2 ++
> >   arch/powerpc/platforms/pseries/cc_platform.c | 26 ++++++++++++++++++++
> >   3 files changed, 29 insertions(+)
> >   create mode 100644 arch/powerpc/platforms/pseries/cc_platform.c
>
> Michael,
>
> can I get an ACK for the ppc bits to carry them through the tip tree
> pls?
>
> Btw, on a related note, cross-compiling this throws the following error here:
>
> $ make CROSS_COMPILE=/home/share/src/crosstool/gcc-9.4.0-nolibc/powerpc64-linux/bin/powerpc64-linux- V=1 ARCH=powerpc
>
> ...
>
> /home/share/src/crosstool/gcc-9.4.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc -Wp,-MD,arch/powerpc/boot/.crt0.o.d -D__ASSEMBLY__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc -include ./include/linux/compiler_attributes.h -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -m32 -isystem /home/share/src/crosstool/gcc-9.4.0-nolibc/powerpc64-linux/bin/../lib/gcc/powerpc64-linux/9.4.0/include -mbig-endian -nostdinc -c -o arch/powerpc/boot/crt0.o arch/powerpc/boot/crt0.S
> In file included from <command-line>:
> ././include/linux/compiler_attributes.h:62:5: warning: "__has_attribute" is not defined, evaluates to 0 [-Wundef]
>     62 | #if __has_attribute(__assume_aligned__)
>        |     ^~~~~~~~~~~~~~~
> ././include/linux/compiler_attributes.h:62:20: error: missing binary operator before token "("
>     62 | #if __has_attribute(__assume_aligned__)
>        |                    ^
> ././include/linux/compiler_attributes.h:88:5: warning: "__has_attribute" is not defined, evaluates to 0 [-Wundef]
>     88 | #if __has_attribute(__copy__)
>        |     ^~~~~~~~~~~~~~~
> ...
>
> Known issue?
>
> This __has_attribute() thing is supposed to be supported
> in gcc since 5.1 and I'm using the crosstool stuff from
> https://www.kernel.org/pub/tools/crosstool/ and gcc-9.4 above is pretty
> new so that should not happen actually.
>
> But it does...
>
> Hmmm.


Yes, see 
https://lore.kernel.org/linuxppc-dev/20210914123919.58203eef@xxxxxxxxxxxxxxxx/T/#t