kernel/linux.git/virt/kvm/arm/arch_timer.c, branch v5.3.9

KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s

2019-07-05T12:57:25+00:00

Currently, the {read,write}_sysreg_el*() accessors for accessing particular ELs' sysregs in the presence of VHE rely on some local hacks and define their system register encodings in a way that is inconsistent with the core definitions in . As a result, it is necessary to add duplicate definitions for any system register that already needs a definition in sysreg.h for other reasons. This is a bit of a maintenance headache, and the reasons for the _el*() accessors working the way they do is a bit historical. This patch gets rid of the shadow sysreg definitions in , converts the _el*() accessors to use the core __msr_s/__mrs_s interface, and converts all call sites to use the standard sysreg #define names (i.e., upper case, with SYS_ prefix). This patch will conflict heavily anyway, so the opportunity to clean up some bad whitespace in the context of the changes is taken. The change exposes a few system registers that have no sysreg.h definition, due to msr_s/mrs_s being used in place of msr/mrs: additions are made in order to fill in the gaps. Signed-off-by: Dave Martin Cc: Catalin Marinas Cc: Christoffer Dall Cc: Mark Rutland Cc: Will Deacon Link: https://www.spinics.net/lists/kvm-arm/msg31717.html [Rebased to v4.21-rc1] Signed-off-by: Sudeep Holla [Rebased to v5.2-rc5, changelog updates] Signed-off-by: Marc Zyngier

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2019-06-20T20:50:37+00:00

Pull kvm fixes from Paolo Bonzini: "Fixes for ARM and x86, plus selftest patches and nicer structs for nested state save/restore" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: nVMX: reorganize initial steps of vmx_set_nested_state KVM: arm/arm64: Fix emulated ptimer irq injection tests: kvm: Check for a kernel warning kvm: tests: Sort tests in the Makefile alphabetically KVM: x86/mmu: Allocate PAE root array when using SVM's 32-bit NPT KVM: x86: Modify struct kvm_nested_state to have explicit fields for data KVM: fix typo in documentation KVM: nVMX: use correct clean fields when copying from eVMCS KVM: arm/arm64: vgic: Fix kvm_device leak in vgic_its_destroy KVM: arm64: Filter out invalid core register IDs in KVM_GET_REG_LIST KVM: arm64: Implement vq_present() as a macro

KVM: arm/arm64: Fix emulated ptimer irq injection

2019-06-19T14:47:52+00:00

The emulated ptimer needs to track the level changes, otherwise the the interrupt will never get deasserted, resulting in the guest getting stuck in an interrupt storm if it enables ptimer interrupts. This was found with kvm-unit-tests; the ptimer tests hung as soon as interrupts were enabled. Typical Linux guests don't have a problem as they prefer using the virtual timer. Fixes: bee038a674875 ("KVM: arm/arm64: Rework the timer code to use a timer_map") Signed-off-by: Andrew Jones [Simplified the patch to res we only care about emulated timers here] Signed-off-by: Marc Zyngier

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333

2019-06-05T15:37:06+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 136 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de Signed-off-by: Greg Kroah-Hartman

KVM: arm/arm64: Don't emulate virtual timers on userspace ioctls

2019-04-25T13:13:31+00:00

When a VCPU never runs before a guest exists, but we set timer registers up via ioctls, the associated hrtimer might never get cancelled. Since we moved vcpu_load/put into the arch-specific implementations and only have load/put for KVM_RUN, we won't ever have a scheduled hrtimer for emulating a timer when modifying the timer state via an ioctl from user space. All we need to do is make sure that we pick up the right state when we load the timer state next time userspace calls KVM_RUN again. We also do not need to worry about this interacting with the bg_timer, because if we were in WFI from the guest, and somehow ended up in a kvm_arm_timer_set_reg, it means that: 1. the VCPU thread has received a signal, 2. we have called vcpu_load when being scheduled in again, 3. we have called vcpu_put when we returned to userspace for it to issue another ioctl And therefore will not have a bg_timer programmed and the event is treated as a spurious wakeup from WFI if userspace decides to run the vcpu again even if there are not virtual interrupts. This fixes stray virtual timer interrupts triggered by an expiring hrtimer, which happens after a failed live migration, for instance. Fixes: bee038a674875 ("KVM: arm/arm64: Rework the timer code to use a timer_map") Signed-off-by: Christoffer Dall Reported-by: Andre Przywara Tested-by: Andre Przywara Signed-off-by: Andre Przywara Signed-off-by: Marc Zyngier

KVM: arm/arm64: arch_timer: Fix CNTP_TVAL calculation

2019-03-30T10:06:00+00:00

Recently the generic timer test of kvm-unit-tests failed to complete (stalled) when a physical timer is being used. This issue is caused by incorrect update of CNTP_CVAL when CNTP_TVAL is being accessed, introduced by 'Commit 84135d3d18da ("KVM: arm/arm64: consolidate arch timer trap handlers")'. According to Arm ARM, the read/write behavior of accesses to the TVAL registers is expected to be: * READ: TimerValue = (CompareValue – (Counter - Offset) * WRITE: CompareValue = ((Counter - Offset) + Sign(TimerValue) This patch fixes the TVAL read/write code path according to the specification. Fixes: 84135d3d18da ("KVM: arm/arm64: consolidate arch timer trap handlers") Signed-off-by: Wei Huang [maz: commit message tidy-up] Signed-off-by: Marc Zyngier

KVM: arm/arm64: Remove unused timer variable

2019-02-22T09:41:52+00:00

The 'timer' local variable became unused after commit bee038a67487 ("KVM: arm/arm64: Rework the timer code to use a timer_map"). Remove it to avoid [-Wunused-but-set-variable] warning. Cc: Christoffer Dall Cc: James Morse Cc: Suzuki K Pouloze Reviewed-by: Julien Thierry Signed-off-by: Shaokun Zhang Signed-off-by: Marc Zyngier

KVM: arm/arm64: arch_timer: Mark physical interrupt active when a virtual interrupt is pending

2019-02-19T21:05:50+00:00

When a guest gets scheduled, KVM performs a "load" operation, which for the timer includes evaluating the virtual "active" state of the interrupt, and replicating it on the physical side. This ensures that the deactivation in the guest will also take place in the physical GIC distributor. If the interrupt is not yet active, we flag it as inactive on the physical side. This means that on restoring the timer registers, if the timer has expired, we'll immediately take an interrupt. That's absolutely fine, as the interrupt will then be flagged as active on the physical side. What this assumes though is that we'll enter the guest right after having taken the interrupt, and that the guest will quickly ACK the interrupt, making it active at on the virtual side. It turns out that quite often, this assumption doesn't really hold. The guest may be preempted on the back on this interrupt, either from kernel space or whilst running at EL1 when a host interrupt fires. When this happens, we repeat the whole sequence on the next load (interrupt marked as inactive, timer registers restored, interrupt fires). And if it takes a really long time for a guest to activate the interrupt (as it does with nested virt), we end-up with many such events in quick succession, leading to the guest only making very slow progress. This can also be seen with the number of virtual timer interrupt on the host being far greater than the same number in the guest. An easy way to fix this is to evaluate the timer state when performing the "load" operation, just like we do when the interrupt actually fires. If the timer has a pending virtual interrupt at this stage, then we can safely flag the physical interrupt as being active, which prevents spurious exits. Signed-off-by: Marc Zyngier

KVM: arm/arm64: Rework the timer code to use a timer_map

2019-02-19T21:05:43+00:00

We are currently emulating two timers in two different ways. When we add support for nested virtualization in the future, we are going to be emulating either two timers in two diffferent ways, or four timers in a single way. We need a unified data structure to keep track of how we map virtual state to physical state and we need to cleanup some of the timer code to operate more independently on a struct arch_timer_context instead of trying to consider the global state of the VCPU and recomputing all state. Co-written with Marc Zyngier Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systems

2019-02-19T21:05:42+00:00

VHE systems don't have to emulate the physical timer, we can simply assign the EL1 physical timer directly to the VM as the host always uses the EL2 timers. In order to minimize the amount of cruft, AArch32 gets definitions for the physical timer too, but is should be generally unused on this architecture. Co-written with Marc Zyngier Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall