mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 19:56:18 +00:00
18863bdd60
The various syscall-related MSRs are fairly expensive to switch. Currently we switch them on every vcpu preemption, which is far too often: - if we're switching to a kernel thread (idle task, threaded interrupt, kernel-mode virtio server (vhost-net), for example) and back, then there's no need to switch those MSRs since kernel threasd won't be exiting to userspace. - if we're switching to another guest running an identical OS, most likely those MSRs will have the same value, so there's little point in reloading them. - if we're running the same OS on the guest and host, the MSRs will have identical values and reloading is unnecessary. This patch uses the new user return notifiers to implement last-minute switching, and checks the msr values to avoid unnecessary reloading. Signed-off-by: Avi Kivity <avi@redhat.com>
71 lines
1.9 KiB
Text
71 lines
1.9 KiB
Text
#
|
|
# KVM configuration
|
|
#
|
|
|
|
source "virt/kvm/Kconfig"
|
|
|
|
menuconfig VIRTUALIZATION
|
|
bool "Virtualization"
|
|
depends on HAVE_KVM || X86
|
|
default y
|
|
---help---
|
|
Say Y here to get to see options for using your Linux host to run other
|
|
operating systems inside virtual machines (guests).
|
|
This option alone does not add any kernel code.
|
|
|
|
If you say N, all options in this submenu will be skipped and disabled.
|
|
|
|
if VIRTUALIZATION
|
|
|
|
config KVM
|
|
tristate "Kernel-based Virtual Machine (KVM) support"
|
|
depends on HAVE_KVM
|
|
# for device assignment:
|
|
depends on PCI
|
|
select PREEMPT_NOTIFIERS
|
|
select MMU_NOTIFIER
|
|
select ANON_INODES
|
|
select HAVE_KVM_IRQCHIP
|
|
select HAVE_KVM_EVENTFD
|
|
select KVM_APIC_ARCHITECTURE
|
|
select USER_RETURN_NOTIFIER
|
|
---help---
|
|
Support hosting fully virtualized guest machines using hardware
|
|
virtualization extensions. You will need a fairly recent
|
|
processor equipped with virtualization extensions. You will also
|
|
need to select one or more of the processor modules below.
|
|
|
|
This module provides access to the hardware capabilities through
|
|
a character device node named /dev/kvm.
|
|
|
|
To compile this as a module, choose M here: the module
|
|
will be called kvm.
|
|
|
|
If unsure, say N.
|
|
|
|
config KVM_INTEL
|
|
tristate "KVM for Intel processors support"
|
|
depends on KVM
|
|
---help---
|
|
Provides support for KVM on Intel processors equipped with the VT
|
|
extensions.
|
|
|
|
To compile this as a module, choose M here: the module
|
|
will be called kvm-intel.
|
|
|
|
config KVM_AMD
|
|
tristate "KVM for AMD processors support"
|
|
depends on KVM
|
|
---help---
|
|
Provides support for KVM on AMD processors equipped with the AMD-V
|
|
(SVM) extensions.
|
|
|
|
To compile this as a module, choose M here: the module
|
|
will be called kvm-amd.
|
|
|
|
# OK, it's a little counter-intuitive to do this, but it puts it neatly under
|
|
# the virtualization menu.
|
|
source drivers/lguest/Kconfig
|
|
source drivers/virtio/Kconfig
|
|
|
|
endif # VIRTUALIZATION
|