0eaeafa10f
From: Martin Schwidefsky <schwidefsky@de.ibm.com> This patch fixes a bug with cpu bound guest on kvm-s390. Sometimes it was impossible to deliver a signal to a spinning guest. We used preemption as a circumvention. The preemption notifiers called vcpu_load, which checked for pending signals and triggered a host intercept. But even with preemption, a sigkill was not delivered immediately. This patch changes the low level host interrupt handler to check for the SIE instruction, if TIF_WORK is set. In that case we change the instruction pointer of the return PSW to rerun the vcpu_run loop. The kvm code sees an intercept reason 0 if that happens. This patch adds accounting for these types of intercept as well. The advantages: - works with and without preemption - signals are delivered immediately - much better host latencies without preemption Acked-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
46 lines
1.1 KiB
Text
46 lines
1.1 KiB
Text
#
|
|
# KVM configuration
|
|
#
|
|
config HAVE_KVM
|
|
bool
|
|
|
|
menuconfig VIRTUALIZATION
|
|
bool "Virtualization"
|
|
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 && EXPERIMENTAL
|
|
select PREEMPT_NOTIFIERS
|
|
select ANON_INODES
|
|
select S390_SWITCH_AMODE
|
|
---help---
|
|
Support hosting paravirtualized guest machines using the SIE
|
|
virtualization capability on the mainframe. This should work
|
|
on any 64bit machine.
|
|
|
|
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_TRACE
|
|
bool
|
|
|
|
# OK, it's a little counter-intuitive to do this, but it puts it neatly under
|
|
# the virtualization menu.
|
|
source drivers/virtio/Kconfig
|
|
|
|
endif # VIRTUALIZATION
|