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>
45 lines
1.1 KiB
Text
45 lines
1.1 KiB
Text
#
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# KVM configuration
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#
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config HAVE_KVM
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bool
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menuconfig VIRTUALIZATION
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bool "Virtualization"
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default y
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---help---
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Say Y here to get to see options for using your Linux host to run other
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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 disabled.
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if VIRTUALIZATION
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config KVM
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tristate "Kernel-based Virtual Machine (KVM) support"
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depends on HAVE_KVM && EXPERIMENTAL
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select PREEMPT_NOTIFIERS
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select ANON_INODES
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select S390_SWITCH_AMODE
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---help---
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Support hosting paravirtualized guest machines using the SIE
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virtualization capability on the mainframe. This should work
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on any 64bit machine.
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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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To compile this as a module, choose M here: the module
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will be called kvm.
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If unsure, say N.
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config KVM_TRACE
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bool
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# OK, it's a little counter-intuitive to do this, but it puts it neatly under
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# the virtualization menu.
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source drivers/virtio/Kconfig
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endif # VIRTUALIZATION
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