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Merge tag 'kvm-arm-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

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KVM/ARM Changes for v4.12.

Changes include:
 - Using the common sysreg definitions between KVM and arm64
 - Improved hyp-stub implementation with support for kexec and kdump on the 32-bit side
 - Proper PMU exception handling
 - Performance improvements of our GIC handling
 - Support for irqchip in userspace with in-kernel arch-timers and PMU support
 - A fix for a race condition in our PSCI code

Conflicts:
	Documentation/virtual/kvm/api.txt
	include/uapi/linux/kvm.h
This commit is contained in:
Paolo Bonzini
2017-04-27 17:33:14 +02:00
parent 70f3aac964 1edb632133
commit c24a7be211
50 changed files with 1163 additions and 927 deletions
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41
Documentation/virtual/kvm/api.txt
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@@ -4120,3 +4120,44 @@ This capability indicates that guest using memory monotoring instructions
(MWAIT/MWAITX) to stop the virtual CPU will not cause a VM exit. As such time
spent while virtual CPU is halted in this way will then be accounted for as
guest running time on the host (as opposed to e.g. HLT).
8.9 KVM_CAP_ARM_USER_IRQ
Architectures: arm, arm64
This capability, if KVM_CHECK_EXTENSION indicates that it is available, means
that if userspace creates a VM without an in-kernel interrupt controller, it
will be notified of changes to the output level of in-kernel emulated devices,
which can generate virtual interrupts, presented to the VM.
For such VMs, on every return to userspace, the kernel
updates the vcpu's run->s.regs.device_irq_level field to represent the actual
output level of the device.
Whenever kvm detects a change in the device output level, kvm guarantees at
least one return to userspace before running the VM. This exit could either
be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way,
userspace can always sample the device output level and re-compute the state of
the userspace interrupt controller. Userspace should always check the state
of run->s.regs.device_irq_level on every kvm exit.
The value in run->s.regs.device_irq_level can represent both level and edge
triggered interrupt signals, depending on the device. Edge triggered interrupt
signals will exit to userspace with the bit in run->s.regs.device_irq_level
set exactly once per edge signal.
The field run->s.regs.device_irq_level is available independent of
run->kvm_valid_regs or run->kvm_dirty_regs bits.
If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a
number larger than 0 indicating the version of this capability is implemented
and thereby which bits in in run->s.regs.device_irq_level can signal values.
Currently the following bits are defined for the device_irq_level bitmap:
KVM_CAP_ARM_USER_IRQ >= 1:
KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer
KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer
KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal
Future versions of kvm may implement additional events. These will get
indicated by returning a higher number from KVM_CHECK_EXTENSION and will be
listed above.