Merge tag 'kvmarm-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.16

* New features:

  - Add large stage-2 mapping support for non-protected pKVM guests,
    clawing back some performance.

  - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and
    protected modes.

  - Enable nested virtualisation support on systems that support it
    (yes, it has been a long time coming), though it is disabled by
    default.

* Improvements, fixes and cleanups:

  - Large rework of the way KVM tracks architecture features and links
    them with the effects of control bits. This ensures correctness of
    emulation (the data is automatically extracted from the published
    JSON files), and helps dealing with the evolution of the
    architecture.

  - Significant changes to the way pKVM tracks ownership of pages,
    avoiding page table walks by storing the state in the hypervisor's
    vmemmap. This in turn enables the THP support described above.

  - New selftest checking the pKVM ownership transition rules

  - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
    even if the host didn't have it.

  - Fixes for the address translation emulation, which happened to be
    rather buggy in some specific contexts.

  - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
    from the number of counters exposed to a guest and addressing a
    number of issues in the process.

  - Add a new selftest for the SVE host state being corrupted by a
    guest.

  - Keep HCR_EL2.xMO set at all times for systems running with the
    kernel at EL2, ensuring that the window for interrupts is slightly
    bigger, and avoiding a pretty bad erratum on the AmpereOne HW.

  - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
    from a pretty bad case of TLB corruption unless accesses to HCR_EL2
    are heavily synchronised.

  - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
    tables in a human-friendly fashion.

  - and the usual random cleanups.

2 files changed, 37 insertions, 1 deletions

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index ad1859f4699e..66754c3417c7 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -3463,7 +3463,8 @@ The initial values are defined as:
 	- FPSIMD/NEON registers: set to 0
 	- SVE registers: set to 0
 	- System registers: Reset to their architecturally defined
-	  values as for a warm reset to EL1 (resp. SVC)
+	  values as for a warm reset to EL1 (resp. SVC) or EL2 (in the
+	  case of EL2 being enabled).
 
 Note that because some registers reflect machine topology, all vcpus
 should be created before this ioctl is invoked.
@@ -3530,6 +3531,17 @@ Possible features:
 	      - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can
 	        no longer be written using KVM_SET_ONE_REG.
 
+	- KVM_ARM_VCPU_HAS_EL2: Enable Nested Virtualisation support,
+	  booting the guest from EL2 instead of EL1.
+	  Depends on KVM_CAP_ARM_EL2.
+	  The VM is running with HCR_EL2.E2H being RES1 (VHE) unless
+	  KVM_ARM_VCPU_HAS_EL2_E2H0 is also set.
+
+	- KVM_ARM_VCPU_HAS_EL2_E2H0: Restrict Nested Virtualisation
+	  support to HCR_EL2.E2H being RES0 (non-VHE).
+	  Depends on KVM_CAP_ARM_EL2_E2H0.
+	  KVM_ARM_VCPU_HAS_EL2 must also be set.
+
 4.83 KVM_ARM_PREFERRED_TARGET
 -----------------------------
 
diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
index 31a9576c07af..60bf205cb373 100644
--- a/Documentation/virt/kvm/devices/vcpu.rst
+++ b/Documentation/virt/kvm/devices/vcpu.rst
@@ -137,6 +137,30 @@ exit_reason = KVM_EXIT_FAIL_ENTRY and populate the fail_entry struct by setting
 hardare_entry_failure_reason field to KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED and
 the cpu field to the processor id.
 
+1.5 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_SET_NR_COUNTERS
+--------------------------------------------------
+
+:Parameters: in kvm_device_attr.addr the address to an unsigned int
+	     representing the maximum value taken by PMCR_EL0.N
+
+:Returns:
+
+	 =======  ====================================================
+	 -EBUSY   PMUv3 already initialized, a VCPU has already run or
+                  an event filter has already been set
+	 -EFAULT  Error accessing the value pointed to by addr
+	 -ENODEV  PMUv3 not supported or GIC not initialized
+	 -EINVAL  No PMUv3 explicitly selected, or value of N out of
+	 	  range
+	 =======  ====================================================
+
+Set the number of implemented event counters in the virtual PMU. This
+mandates that a PMU has explicitly been selected via
+KVM_ARM_VCPU_PMU_V3_SET_PMU, and will fail when no PMU has been
+explicitly selected, or the number of counters is out of range for the
+selected PMU. Selecting a new PMU cancels the effect of setting this
+attribute.
+
 2. GROUP: KVM_ARM_VCPU_TIMER_CTRL
 =================================