On Wed, Jun 22, 2022 at 08:05:12AM -0700, Jerry Snitselaar wrote: > On Wed, Jun 22, 2022 at 7:52 AM Baolu Lu <baolu...@linux.intel.com> wrote: > > > > On 2022/6/16 02:36, 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.w...@hpe.com> > > > Reviewed-by: Kevin Tian<kevin.t...@intel.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. > > > > > > v3: Make the config option dependent upon DMAR_TABLE, as it is not used > > > without this. > > > > > > drivers/iommu/intel/Kconfig | 7 +++++++ > > > include/linux/dmar.h | 6 +----- > > > 2 files changed, 8 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig > > > index 39a06d245f12..07aaebcb581d 100644 > > > --- a/drivers/iommu/intel/Kconfig > > > +++ b/drivers/iommu/intel/Kconfig > > > @@ -9,6 +9,13 @@ config DMAR_PERF > > > config DMAR_DEBUG > > > bool > > > > > > +config DMAR_UNITS_SUPPORTED > > > + int "Number of DMA Remapping Units supported" > > > + depends on DMAR_TABLE > > > + default 1024 if MAXSMP > > > + default 128 if X86_64 > > > + default 64 > > > > With this patch applied, the IOMMU configuration looks like: > > > > [*] AMD IOMMU support > > <M> AMD IOMMU Version 2 driver > > [*] Enable AMD IOMMU internals in DebugFS > > (1024) Number of DMA Remapping Units supported <<<< NEW > > [*] Support for Intel IOMMU using DMA Remapping Devices > > [*] Export Intel IOMMU internals in Debugfs > > [*] Support for Shared Virtual Memory with Intel IOMMU > > [*] Enable Intel DMA Remapping Devices by default > > [*] Enable Intel IOMMU scalable mode by default > > [*] Support for Interrupt Remapping > > [*] OMAP IOMMU Support > > [*] Export OMAP IOMMU internals in DebugFS > > [*] Rockchip IOMMU Support > > > > The NEW item looks confusing. It looks to be a generic configurable > > value though it's actually Intel DMAR specific. Any thoughts? > > > > Best regards, > > baolu > > > > Would moving it under INTEL_IOMMU at least have it show up below > "Support for Intel IOMMU using DMA Remapping Devices"? I'm not sure it > can be better than that, because IRQ_REMAP selects DMAR_TABLE, so we > can't stick it in the if INTEL_IOMMU section. > > Regards, > Jerry
I have no qualms with Jerry's suggestion. --> Steve Wahl -- Steve Wahl, Hewlett Packard Enterprise _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
