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ef748917b5
This patch removes config option of KVM_ARM_MAX_VCPUS, and like other ARCHs, just choose the maximum allowed value from hardware, and follows the reasons: 1) from distribution view, the option has to be defined as the max allowed value because it need to meet all kinds of virtulization applications and need to support most of SoCs; 2) using a bigger value doesn't introduce extra memory consumption, and the help text in Kconfig isn't accurate because kvm_vpu structure isn't allocated until request of creating VCPU is sent from QEMU; 3) the main effect is that the field of vcpus[] in 'struct kvm' becomes a bit bigger(sizeof(void *) per vcpu) and need more cache lines to hold the structure, but 'struct kvm' is one generic struct, and it has worked well on other ARCHs already in this way. Also, the world switch frequecy is often low, for example, it is ~2000 when running kernel building load in VM from APM xgene KVM host, so the effect is very small, and the difference can't be observed in my test at all. Cc: Dann Frazier <dann.frazier@canonical.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
49 lines
1.1 KiB
Plaintext
49 lines
1.1 KiB
Plaintext
#
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# KVM configuration
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#
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source "virt/kvm/Kconfig"
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menuconfig VIRTUALIZATION
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bool "Virtualization"
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---help---
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Say Y here to get to see options for using your Linux host to run
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other operating systems inside virtual machines (guests).
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This option alone does not add any kernel code.
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If you say N, all options in this submenu will be skipped and
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disabled.
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if VIRTUALIZATION
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config KVM
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bool "Kernel-based Virtual Machine (KVM) support"
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depends on MMU && OF
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select PREEMPT_NOTIFIERS
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select ANON_INODES
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select HAVE_KVM_CPU_RELAX_INTERCEPT
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select HAVE_KVM_ARCH_TLB_FLUSH_ALL
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select KVM_MMIO
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select KVM_ARM_HOST
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select KVM_GENERIC_DIRTYLOG_READ_PROTECT
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select SRCU
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select MMU_NOTIFIER
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select KVM_VFIO
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select HAVE_KVM_EVENTFD
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select HAVE_KVM_IRQFD
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depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER
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---help---
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Support hosting virtualized guest machines.
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This module provides access to the hardware capabilities through
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a character device node named /dev/kvm.
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If unsure, say N.
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config KVM_ARM_HOST
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bool
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---help---
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Provides host support for ARM processors.
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endif # VIRTUALIZATION
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