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linux-next/Documentation/virtual/kvm
Eric Auger ae204f80ca KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET
At the moment, the in-kernel emulated ITS is not properly reset.
On guest restart/reset some registers keep their old values and
internal structures like device, ITE, and collection lists are not
freed.

This may lead to various bugs. Among them, we can have incorrect state
backup or failure when saving the ITS state at early guest boot stage.

This patch documents a new attribute, KVM_DEV_ARM_ITS_CTRL_RESET in
the KVM_DEV_ARM_VGIC_GRP_CTRL group.

Upon this action, we can reset registers and especially those
pointing to tables previously allocated by the guest and free
the internal data structures storing the list of devices, collections
and lpis.

The usual approach for device reset of having userspace write
the reset values of the registers to the kernel via the register
read/write APIs doesn't work for the ITS because it has some
internal state (caches) which is not exposed as registers,
and there is no register interface for "drop cached data without
writing it back to RAM". So we need a KVM API which mimics the
hardware's reset line, to provide the equivalent behaviour to
a "pull the power cord out of the back of the machine" reset.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reported-by: wanghaibin <wanghaibin.wang@huawei.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-06 16:23:19 +01:00
..
arm arm/arm64: Add hyp-stub API documentation 2017-04-09 07:49:36 -07:00
devices KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET 2017-11-06 16:23:19 +01:00
00-INDEX KVM: Add halt polling documentation 2016-11-28 11:48:47 +11:00
api.txt kvm: x86: hyperv: make VP_INDEX managed by userspace 2017-07-14 16:28:18 +02:00
cpuid.txt Documentation/kvm: Update cpuid documentation for steal time and pv eoi 2013-09-24 19:12:16 +02:00
halt-polling.txt KVM: Add halt polling documentation 2016-11-28 11:48:47 +11:00
hypercalls.txt KVM: MIPS: Implement HYPCALL emulation 2017-03-28 14:53:33 +01:00
locking.txt kvm: x86: mmu: Update documentation for fast page fault mechanism 2017-01-09 14:46:12 +01:00
mmu.txt kvm: x86: mmu: allow A/D bits to be disabled in an mmu 2017-07-03 11:19:54 +02:00
msr.txt KVM: async_pf: Let guest support delivery of async_pf from guest mode 2017-07-14 14:26:16 +02:00
nested-vmx.txt KVM: nVMX: Documentation 2011-07-12 13:15:22 +03:00
ppc-pv.txt Doc:kvm: Fix typo in Doc/virtual/kvm 2015-10-11 15:35:23 -06:00
review-checklist.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
s390-diag.txt KVM: s390: add documentation for diag 501 2014-04-22 13:24:51 +02:00
timekeeping.txt KVM: doc: Fix typo in doc/virtual/kvm 2013-12-31 17:24:54 -02:00
vcpu-requests.rst KVM: Add documentation for VCPU requests 2017-06-04 16:53:00 +02:00