RE: [PATCH 1/1] X86/Hyper-V:: Fix the circular dependency in IPI enlightenment.

From: KY Srinivasan
Date: Thu Jul 05 2018 - 11:01:33 EST




> -----Original Message-----
> From: Ingo Molnar <mingo.kernel.org@xxxxxxxxx> On Behalf Of Ingo Molnar
> Sent: Wednesday, July 4, 2018 9:11 AM
> To: KY Srinivasan <kys@xxxxxxxxxxxxx>
> Cc: x86@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx;
> apw@xxxxxxxxxxxxx; jasowang@xxxxxxxxxx; tglx@xxxxxxxxxxxxx;
> hpa@xxxxxxxxx; Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>; Michael
> Kelley (EOSG) <Michael.H.Kelley@xxxxxxxxxxxxx>; vkuznets@xxxxxxxxxx
> Subject: Re: [PATCH 1/1] X86/Hyper-V:: Fix the circular dependency in IPI
> enlightenment.
>
>
> * kys@xxxxxxxxxxxxxxxxx <kys@xxxxxxxxxxxxxxxxx> wrote:
>
> > From: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> >
> > The IPI hypercalls depend on being able to map the Linux notion of CPU ID
> > to the hypervisor's notion of the CPU ID. The array hv_vp_index[] provides
> > this mapping. Code for populating this array depends on the IPI
> functionality.
> > Break this circular dependency.
> >
> > Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments")
> >
> > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> > Tested-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> > ---
> > arch/x86/hyperv/hv_apic.c | 5 +++++
> > arch/x86/hyperv/hv_init.c | 5 ++++-
> > arch/x86/include/asm/mshyperv.h | 2 ++
> > 3 files changed, 11 insertions(+), 1 deletion(-)
>
> Ugh, this patch wasn't even build tested, on 64-bit allyes/allmodconfig:
>
> arch/x86/hyperv/hv_apic.c: In function â__send_ipi_maskâ:
> arch/x86/hyperv/hv_apic.c:171:4: error: label âipi_mask_doneâ used but not
> defined
> scripts/Makefile.build:317: recipe for target 'arch/x86/hyperv/hv_apic.o'
> failed
> make[2]: *** [arch/x86/hyperv/hv_apic.o] Error 1

Sorry Ingo. I had a clean build on the linux-next tree (tag: next-20180702) that
I used to base this patch. What was the tree you applied the patch to?

Regards,

K. Y

>
> Thanks,
>
> Ingo