Messages in this thread Patch in this message | | | Date | Thu, 12 May 2022 18:12:34 -0500 | From | Steve Wahl <> | Subject | Re: [PATCH v2] iommu/vt-d: Make DMAR_UNITS_SUPPORTED a config setting |
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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?
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
-- Steve Wahl, Hewlett Packard Enterprise
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