Messages in this thread | | | Date | Fri, 13 May 2022 10:09:46 +0800 | Subject | Re: [PATCH v2] iommu/vt-d: Make DMAR_UNITS_SUPPORTED a config setting | From | Baolu Lu <> |
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On 2022/5/13 07:12, Steve Wahl 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> > > I've received a report from the kernel test robot <lkp@intel.com>, > that this patch causes an error (shown below) when > CONFIG_IOMMU_SUPPORT is not set. > > In my opinion, this is because include/linux/dmar.h and > include/linux/intel-iommu are being #included when they are not really > being used. > > I've tried placing the contents of intel-iommu.h within an #ifdef > CONFIG_INTEL_IOMMU, and that fixes the problem. > > Two questions: > > A) Is this the desired approach to to the fix?
Most part of include/linux/intel-iommu.h is private to Intel IOMMU driver. They should be put in a header like drivers/iommu/intel /iommu.h. Eventually, we should remove include/linux/intel-iommu.h and device drivers interact with iommu subsystem through the IOMMU kAPIs.
Best regards, baolu
> > B) Should it be a separate patch, or added onto this patch as a v3? > > Error message: ------------------------------ > > In file included from include/linux/intel-iommu.h:21, > from arch/x86/kvm/x86.c:44: >>> include/linux/dmar.h:21:33: error: 'CONFIG_DMAR_UNITS_SUPPORTED' undeclared here (not in a function); did you mean 'DMAR_UNITS_SUPPORTED'? > 21 | #define DMAR_UNITS_SUPPORTED CONFIG_DMAR_UNITS_SUPPORTED > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > include/linux/intel-iommu.h:531:35: note: in expansion of macro 'DMAR_UNITS_SUPPORTED' > 531 | unsigned int iommu_refcnt[DMAR_UNITS_SUPPORTED]; > | ^~~~~~~~~~~~~~~~~~~~ > > > vim +21 include/linux/dmar.h > > 20 > > 21 #define DMAR_UNITS_SUPPORTED CONFIG_DMAR_UNITS_SUPPORTED > 22 > > Initial stab at fixing it: ------------------------------ > > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index 2f9891cb3d00..916fd7b5bcb5 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -10,6 +10,8 @@ > #ifndef _INTEL_IOMMU_H_ > #define _INTEL_IOMMU_H_ > > +#ifdef CONFIG_INTEL_IOMMU > + > #include <linux/types.h> > #include <linux/iova.h> > #include <linux/io.h> > @@ -831,4 +833,6 @@ static inline const char *decode_prq_descriptor(char *str, size_t size, > return str; > } > > +#endif /* CONFIG_IOMMU_SUPPORT */ > + > #endif > > > Thanks. > > --> Steve Wahl > >
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