We currently find out about the presence of a HW PMU (or the handling
of that PMU by perf, which amounts to the same thing) in a fairly
roundabout way, by checking the number of counters available to perf.
That's good enough for now, but we will soon need to find about about
that on paths where perf is out of reach (in the world switch).

Instead, let's turn kvm_arm_support_pmu_v3() into a static key.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210209114844.3278746-2-maz@kernel.org
Message-Id: <20210305185254.3730990-5-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM_ARM_PMU only existed for the benefit of 32bit ARM hosts,
and makes no sense now that we are 64bit only. Get rid of it.

Signed-off-by: Marc Zyngier <maz@kernel.org>

Signed-off-by: Marc Zyngier <maz@kernel.org>

In order to reduce the impact of the VPT parsing happening on the GIC,
we can split the vcpu reseidency in two phases:

- programming GICR_VPENDBASER: this still happens in vcpu_load()
- checking for the VPT parsing to be complete: this can happen
  on vcpu entry (in kvm_vgic_flush_hwstate())

This allows the GIC and the CPU to work in parallel, rewmoving some
of the entry overhead.

Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201128141857.983-3-lushenming@huawei.com

The PMU ready state has no user left. Goodbye.

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Pull KVM updates from Paolo Bonzini:
 "For x86, there is a new alternative and (in the future) more scalable
  implementation of extended page tables that does not need a reverse
  map from guest physical addresses to host physical addresses.

  For now it is disabled by default because it is still lacking a few of
  the existing MMU's bells and whistles. However it is a very solid
  piece of work and it is already available for people to hammer on it.

  Other updates:

  ARM:
   - New page table code for both hypervisor and guest stage-2
   - Introduction of a new EL2-private host context
   - Allow EL2 to have its own private per-CPU variables
   - Support of PMU event filtering
   - Complete rework of the Spectre mitigation

  PPC:
   - Fix for running nested guests with in-kernel IRQ chip
   - Fix race condition causing occasional host hard lockup
   - Minor cleanups and bugfixes

  x86:
   - allow trapping unknown MSRs to userspace
   - allow userspace to force #GP on specific MSRs
   - INVPCID support on AMD
   - nested AMD cleanup, on demand allocation of nested SVM state
   - hide PV MSRs and hypercalls for features not enabled in CPUID
   - new test for MSR_IA32_TSC writes from host and guest
   - cleanups: MMU, CPUID, shared MSRs
   - LAPIC latency optimizations ad bugfixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (232 commits)
  kvm: x86/mmu: NX largepage recovery for TDP MMU
  kvm: x86/mmu: Don't clear write flooding count for direct roots
  kvm: x86/mmu: Support MMIO in the TDP MMU
  kvm: x86/mmu: Support write protection for nesting in tdp MMU
  kvm: x86/mmu: Support disabling dirty logging for the tdp MMU
  kvm: x86/mmu: Support dirty logging for the TDP MMU
  kvm: x86/mmu: Support changed pte notifier in tdp MMU
  kvm: x86/mmu: Add access tracking for tdp_mmu
  kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU
  kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU
  kvm: x86/mmu: Add TDP MMU PF handler
  kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg
  kvm: x86/mmu: Support zapping SPTEs in the TDP MMU
  KVM: Cache as_id in kvm_memory_slot
  kvm: x86/mmu: Add functions to handle changed TDP SPTEs
  kvm: x86/mmu: Allocate and free TDP MMU roots
  kvm: x86/mmu: Init / Uninit the TDP MMU
  kvm: x86/mmu: Introduce tdp_iter
  KVM: mmu: extract spte.h and spte.c
  KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp
  ...

As we can now hide events from the guest, let's also adjust its view of
PCMEID{0,1}_EL1 so that it can figure out why some common events are not
counting as they should.

The astute user can still look into the TRM for their CPU and find out
they've been cheated, though. Nobody's perfect.

Signed-off-by: Marc Zyngier <maz@kernel.org>

kvm_vcpu_kick() is not NMI safe. When the overflow handler is called from
NMI context, defer waking the vcpu to an irq_work queue.

A vcpu can be freed while it's not running by kvm_destroy_vm(). Prevent
running the irq_work for a non-existent vcpu by calling irq_work_sync() on
the PMU destroy path.

[Alexandru E.: Added irq_work_sync()]

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox)
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Pouloze <suzuki.poulose@arm.com>
Cc: kvm@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
Link: https://lore.kernel.org/r/20200924110706.254996-6-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

Move the timer gsisters to the sysreg file. This will further help when
they are directly changed by a nesting hypervisor in the VNCR page.

This requires moving the initialisation of the timer struct so that some
of the helpers (such as arch_timer_ctx_index) can work correctly at an
early stage.

Signed-off-by: Marc Zyngier <maz@kernel.org>

kvm_timer_sync_hwstate() has nothing to do with the timer HW state,
but more to do with the state of a userspace interrupt controller.
Change the suffix from _hwstate to_user, in keeping with the rest
of the code.

Signed-off-by: Marc Zyngier <maz@kernel.org>