config VFIO_IOMMU_TYPE1 tristate depends on VFIO default n config VFIO_IOMMU_SPAPR_TCE tristate depends on VFIO && SPAPR_TCE_IOMMU default n config VFIO_SPAPR_EEH tristate depends on EEH && VFIO_IOMMU_SPAPR_TCE default n config VFIO_VIRQFD tristate depends on VFIO && EVENTFD default n menuconfig VFIO tristate "VFIO Non-Privileged userspace driver framework" depends on IOMMU_API select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM_SMMU || ARM_SMMU_V3) select VFIO_IOMMU_SPAPR_TCE if (PPC_POWERNV || PPC_PSERIES) select VFIO_SPAPR_EEH if (PPC_POWERNV || PPC_PSERIES) select ANON_INODES help VFIO provides a framework for secure userspace device drivers. See Documentation/vfio.txt for more details. If you don't know what to do here, say N. menuconfig VFIO_NOIOMMU bool "VFIO No-IOMMU support" depends on VFIO help VFIO is built on the ability to isolate devices using the IOMMU. Only with an IOMMU can userspace access to DMA capable devices be considered secure. VFIO No-IOMMU mode enables IOMMU groups for devices without IOMMU backing for the purpose of re-using the VFIO infrastructure in a non-secure mode. Use of this mode will result in an unsupportable kernel and will therefore taint the kernel. Device assignment to virtual machines is also not possible with this mode since there is no IOMMU to provide DMA translation. If you don't know what to do here, say N. source "drivers/vfio/pci/Kconfig" source "drivers/vfio/platform/Kconfig" source "drivers/vfio/mdev/Kconfig" source "virt/lib/Kconfig" cgi/linux/net-next.git/?h=nds-private-remove'>summaryrefslogtreecommitdiff
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authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2017-02-03 14:18:39 -0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-02-04 00:11:08 +0100
commit6e978b22efa1db9f6e71b24440b5f1d93e968ee3 (patch)
treec666f7a26b860674848949e39a610222b0723f89 /tools/Makefile
parent3c223c19aea85d3dda1416c187915f4a30b04b1f (diff)
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in HWP mode, even if running under sustained 100% utilization. This occurs when the HWP.EPP (Energy Performance Preference) is set to "balance_power" (0x80) -- the default on most systems. It occurs because the platform BIOS may erroneously enable an energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not recommended to be enabled on this SKU. On the failing systems, this BIOS issue was not discovered when the desktop motherboard was tested with Windows, because the BIOS also neglects to provide the ACPI/CPPC table, that Windows requires to enable HWP, and so Windows runs in legacy P-state mode, where this setting has no effect. Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and so it runs in HWP mode, exposing this incorrect BIOS configuration. There are several ways to address this problem. First, Linux can also run in legacy P-state mode on this system. As intel_pstate is how Linux enables HWP, booting with "intel_pstate=disable" will run in acpi-cpufreq/ondemand legacy p-state mode. Or second, the "performance" governor can be used with intel_pstate, which will modify HWP.EPP to 0. Or third, starting in 4.10, the /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference attribute in can be updated from "balance_power" to "performance". Or fourth, apply this patch, which fixes the erroneous setting of MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default configuration to function as designed. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Reviewed-by: Len Brown <len.brown@intel.com> Cc: 4.6+ <stable@vger.kernel.org> # 4.6+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'tools/Makefile')