de56a948b9
This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
138 lines
3.6 KiB
Plaintext
138 lines
3.6 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
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select PREEMPT_NOTIFIERS
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select ANON_INODES
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config KVM_BOOK3S_HANDLER
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bool
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config KVM_BOOK3S_32_HANDLER
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bool
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select KVM_BOOK3S_HANDLER
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select KVM_MMIO
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config KVM_BOOK3S_64_HANDLER
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bool
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select KVM_BOOK3S_HANDLER
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config KVM_BOOK3S_PR
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bool
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select KVM_MMIO
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config KVM_BOOK3S_32
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tristate "KVM support for PowerPC book3s_32 processors"
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depends on EXPERIMENTAL && PPC_BOOK3S_32 && !SMP && !PTE_64BIT
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select KVM
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select KVM_BOOK3S_32_HANDLER
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select KVM_BOOK3S_PR
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---help---
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Support running unmodified book3s_32 guest kernels
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in virtual machines on book3s_32 host processors.
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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_BOOK3S_64
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tristate "KVM support for PowerPC book3s_64 processors"
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depends on EXPERIMENTAL && PPC_BOOK3S_64
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select KVM_BOOK3S_64_HANDLER
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select KVM
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---help---
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Support running unmodified book3s_64 and book3s_32 guest kernels
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in virtual machines on book3s_64 host processors.
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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_BOOK3S_64_HV
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bool "KVM support for POWER7 using hypervisor mode in host"
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depends on KVM_BOOK3S_64
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---help---
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Support running unmodified book3s_64 guest kernels in
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virtual machines on POWER7 processors that have hypervisor
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mode available to the host.
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If you say Y here, KVM will use the hardware virtualization
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facilities of POWER7 (and later) processors, meaning that
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guest operating systems will run at full hardware speed
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using supervisor and user modes. However, this also means
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that KVM is not usable under PowerVM (pHyp), is only usable
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on POWER7 (or later) processors, and can only emulate
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POWER5+, POWER6 and POWER7 processors.
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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_BOOK3S_64_PR
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def_bool y
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depends on KVM_BOOK3S_64 && !KVM_BOOK3S_64_HV
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select KVM_BOOK3S_PR
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config KVM_440
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bool "KVM support for PowerPC 440 processors"
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depends on EXPERIMENTAL && 44x
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select KVM
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select KVM_MMIO
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---help---
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Support running unmodified 440 guest kernels in virtual machines on
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440 host processors.
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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_EXIT_TIMING
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bool "Detailed exit timing"
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depends on KVM_440 || KVM_E500
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---help---
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Calculate elapsed time for every exit/enter cycle. A per-vcpu
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report is available in debugfs kvm/vm#_vcpu#_timing.
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The overhead is relatively small, however it is not recommended for
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production environments.
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If unsure, say N.
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config KVM_E500
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bool "KVM support for PowerPC E500 processors"
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depends on EXPERIMENTAL && E500
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select KVM
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select KVM_MMIO
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---help---
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Support running unmodified E500 guest kernels in virtual machines on
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E500 host processors.
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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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source drivers/vhost/Kconfig
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source drivers/virtio/Kconfig
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endif # VIRTUALIZATION
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