On Mon, Jul 13, 2020 at 01:10:50AM +0200, Sedat Dilek wrote:
> When using Clang's Integrated Assembler (LLVM_IAS=1) we fell over
> ClangBuiltLinux (CBL) issue #1043 where Jian Cai provided a fix.
>
> With Jian's fix applied another issue raised up when CONFIG_HYPERV=m.
>
> It turned out that the conversion of vectors to IDTENTRY_SYSVEC in
> case of CONFIG_HYPERV was incomplete and fails with a build error:
>
> <instantiation>:9:6: error: expected absolute expression
> .if HYPERVISOR_REENLIGHTENMENT_VECTOR == 3
> ^
> <instantiation>:1:1: note: while in macro instantiation
> idtentry HYPERVISOR_REENLIGHTENMENT_VECTOR asm_sysvec_hyperv_reenlightenment
> sysvec_hyperv_reenlightenment has_error_code=0
> ^
> ./arch/x86/include/asm/idtentry.h:627:1: note: while in macro instantiation
> idtentry_sysvec HYPERVISOR_REENLIGHTENMENT_VECTOR
> sysvec_hyperv_reenlightenment;
> ^
> <instantiation>:9:6: error: expected absolute expression
> .if HYPERVISOR_STIMER0_VECTOR == 3
> ^
> <instantiation>:1:1: note: while in macro instantiation
> idtentry HYPERVISOR_STIMER0_VECTOR asm_sysvec_hyperv_stimer0
> sysvec_hyperv_stimer0 has_error_code=0
> ^
> ./arch/x86/include/asm/idtentry.h:628:1: note: while in macro instantiation
> idtentry_sysvec HYPERVISOR_STIMER0_VECTOR sysvec_hyperv_stimer0;
Hmm... Interesting. GCC never complained. Guests are perhaps broken in a
rather subtle way.
>
> I and Nathan double-checked the hyperv(isor) vectors:
>
> $ rg --no-heading
> "HYPERVISOR_REENLIGHTENMENT_VECTOR|HYPERVISOR_STIMER0_VECTOR"
> $ rg --no-heading "HYPERV_REENLIGHTENMENT_VECTOR|HYPERV_STIMER0_VECTOR"
>
> Fix these typos in arch/x86/include/asm/idtentry.h:
>
> HYPERVISOR_REENLIGHTENMENT_VECTOR -> HYPERV_REENLIGHTENMENT_VECTOR
> HYPERVISOR_STIMER0_VECTOR -> HYPERV_STIMER0_VECTOR
>
> For more details see CBL issue #1088.
>
> With both fixes applied I was able to build/assemble with a snapshot
> version of LLVM/Clang from Debian/experimental.
I think the issue found here is independent of the other. This patch
shouldn't need to wait for the other to land.
>
> Cc: Jian Cai <caij2...@gmail.com>
> Cc: clang-built-li...@googlegroups.com
> Reviewed-by: Nathan Chancellor <natechancel...@gmail.com>
> Fixes: a16be368dd3f ("x86/entry: Convert various hypervisor vectors to
> IDTENTRY_SYSVEC")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1043
> Link: https://github.com/ClangBuiltLinux/linux/issues/1088
> Signed-off-by: Sedat Dilek <sedat.di...@gmail.com>
> ---
> arch/x86/include/asm/idtentry.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
> index 513eb2ccbdbf..a811f6c6cf15 100644
> --- a/arch/x86/include/asm/idtentry.h
> +++ b/arch/x86/include/asm/idtentry.h
> @@ -624,8 +624,8 @@ DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR,
> sysvec_kvm_posted_intr_nested
>
> #if IS_ENABLED(CONFIG_HYPERV)
> DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR, sysvec_hyperv_callback);
> -DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_REENLIGHTENMENT_VECTOR,
> sysvec_hyperv_reenlightenment);
> -DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_STIMER0_VECTOR, sysvec_hyperv_stimer0);
> +DECLARE_IDTENTRY_SYSVEC(HYPERV_REENLIGHTENMENT_VECTOR,
> sysvec_hyperv_reenlightenment);
> +DECLARE_IDTENTRY_SYSVEC(HYPERV_STIMER0_VECTOR, sysvec_hyperv_stimer0);
Reviewed-by: Wei Liu <wei....@kernel.org>
Thomas, can you pick this up for 5.8? Thanks.
Wei.
