Messages in this thread | | | From | Jerry Snitselaar <> | Date | Mon, 13 Jun 2022 18:54:13 -0700 | Subject | Re: [PATCH v2] iommu/vt-d: Make DMAR_UNITS_SUPPORTED a config setting |
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On Mon, Jun 13, 2022 at 6:51 PM Baolu Lu <baolu.lu@linux.intel.com> wrote: > > On 2022/6/14 09:44, Jerry Snitselaar wrote: > > On Mon, Jun 13, 2022 at 6:36 PM Baolu Lu<baolu.lu@linux.intel.com> wrote: > >> On 2022/6/14 04:57, Jerry Snitselaar wrote: > >>> On Thu, May 12, 2022 at 10:13:09AM -0500, Steve Wahl wrote: > >>>> To support up to 64 sockets with 10 DMAR units each (640), make the > >>>> value of DMAR_UNITS_SUPPORTED adjustable by a config variable, > >>>> CONFIG_DMAR_UNITS_SUPPORTED, and make it's default 1024 when MAXSMP is > >>>> set. > >>>> > >>>> If the available hardware exceeds DMAR_UNITS_SUPPORTED (previously set > >>>> to MAX_IO_APICS, or 128), it causes these messages: "DMAR: Failed to > >>>> allocate seq_id", "DMAR: Parse DMAR table failure.", and "x2apic: IRQ > >>>> remapping doesn't support X2APIC mode x2apic disabled"; and the system > >>>> fails to boot properly. > >>>> > >>>> Signed-off-by: Steve Wahl<steve.wahl@hpe.com> > >>>> --- > >>>> > >>>> Note that we could not find a reason for connecting > >>>> DMAR_UNITS_SUPPORTED to MAX_IO_APICS as was done previously. Perhaps > >>>> it seemed like the two would continue to match on earlier processors. > >>>> There doesn't appear to be kernel code that assumes that the value of > >>>> one is related to the other. > >>>> > >>>> v2: Make this value a config option, rather than a fixed constant. The default > >>>> values should match previous configuration except in the MAXSMP case. Keeping the > >>>> value at a power of two was requested by Kevin Tian. > >>>> > >>>> drivers/iommu/intel/Kconfig | 6 ++++++ > >>>> include/linux/dmar.h | 6 +----- > >>>> 2 files changed, 7 insertions(+), 5 deletions(-) > >>>> > >>>> diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig > >>>> index 247d0f2d5fdf..fdbda77ac21e 100644 > >>>> --- a/drivers/iommu/intel/Kconfig > >>>> +++ b/drivers/iommu/intel/Kconfig > >>>> @@ -9,6 +9,12 @@ config DMAR_PERF > >>>> config DMAR_DEBUG > >>>> bool > >>>> > >>>> +config DMAR_UNITS_SUPPORTED > >>>> + int "Number of DMA Remapping Units supported" > >>> Also, should there be a "depends on (X86 || IA64)" here? > >> Do you have any compilation errors or warnings? > >> > >> Best regards, > >> baolu > >> > > I think it is probably harmless since it doesn't get used elsewhere, > > but our tooling was complaining to me because DMAR_UNITS_SUPPORTED was > > being autogenerated into the configs for the non-x86 architectures we > > build (aarch64, s390x, ppcle64). > > We have files corresponding to the config options that it looks at, > > and I had one for x86 and not the others so it noticed the > > discrepancy. > > So with "depends on (X86 || IA64)", that tool doesn't complain anymore, > right? > > Best regards, > baolu >
Yes, with the depends it no longer happens.
Regards, Jerry
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