Messages in this thread | | | Date | Fri, 6 Jul 2018 00:23:02 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 1/1] X86/Hyper-V:: Fix the circular dependency in IPI enlightenment. |
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* KY Srinivasan <kys@microsoft.com> wrote:
> > > > -----Original Message----- > > From: Ingo Molnar <mingo.kernel.org@gmail.com> On Behalf Of Ingo Molnar > > Sent: Thursday, July 5, 2018 8:38 AM > > To: KY Srinivasan <kys@microsoft.com> > > Cc: x86@kernel.org; gregkh@linuxfoundation.org; linux- > > kernel@vger.kernel.org; devel@linuxdriverproject.org; olaf@aepfle.de; > > apw@canonical.com; jasowang@redhat.com; tglx@linutronix.de; > > hpa@zytor.com; Stephen Hemminger <sthemmin@microsoft.com>; Michael > > Kelley (EOSG) <Michael.H.Kelley@microsoft.com>; vkuznets@redhat.com > > Subject: Re: [PATCH 1/1] X86/Hyper-V:: Fix the circular dependency in IPI > > enlightenment. > > > > > > * KY Srinivasan <kys@microsoft.com> wrote: > > > > > > > > > > > > -----Original Message----- > > > > From: Ingo Molnar <mingo.kernel.org@gmail.com> On Behalf Of Ingo > > Molnar > > > > Sent: Wednesday, July 4, 2018 9:11 AM > > > > To: KY Srinivasan <kys@microsoft.com> > > > > Cc: x86@kernel.org; gregkh@linuxfoundation.org; linux- > > > > kernel@vger.kernel.org; devel@linuxdriverproject.org; olaf@aepfle.de; > > > > apw@canonical.com; jasowang@redhat.com; tglx@linutronix.de; > > > > hpa@zytor.com; Stephen Hemminger <sthemmin@microsoft.com>; > > Michael > > > > Kelley (EOSG) <Michael.H.Kelley@microsoft.com>; > > vkuznets@redhat.com > > > > Subject: Re: [PATCH 1/1] X86/Hyper-V:: Fix the circular dependency in IPI > > > > enlightenment. > > > > > > > > > > > > * kys@linuxonhyperv.com <kys@linuxonhyperv.com> wrote: > > > > > > > > > From: "K. Y. Srinivasan" <kys@microsoft.com> > > > > > > > > > > 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@microsoft.com> > > > > > Tested-by: Michael Kelley <mikelley@microsoft.com> > > > > > --- > > > > > 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 ‘__send_ipi_mask’: > > > > arch/x86/hyperv/hv_apic.c:171:4: error: label ‘ipi_mask_done’ 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? > > > > If you look at the error message, it won't build against *any* tree, because > > there's no 'ipi_mask_done' label either in the kernel source, or introduced > > by the patch. > > > > So whatever tree you used it on, if you build arch/x86/hyperv/hv_apic.o it > > should > > be broken. > > Ingo, > > I am confused. The label ipi_mask_done was introduced in this patch > (the patch under question fixes a circular dependency in this patch): > > commit 68bb7bfb7985df2bd15c2dc975cb68b7a901488a > Author: K. Y. Srinivasan <kys@microsoft.com> > Date: Wed May 16 14:53:31 2018 -0700 > > X86/Hyper-V: Enable IPI enlightenments > > Hyper-V supports hypercalls to implement IPI; use them. > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Reviewed-by: Michael Kelley <mikelley@microsoft.com> > > This patch was committed by Thomas some weeks ago and is in linux-next. > This patch is also in 4.18-rc3.
And then that name was changed to a different label in:
4bd06060762b: x86/hyper-v: Use cheaper HVCALL_SEND_IPI hypercall when possible
So maybe you were testing on an older kernel. Could you try the latest -tip?
Thanks,
Ingo
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