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author | Paolo Bonzini <pbonzini@redhat.com> | 2023-10-31 23:37:07 +0300 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-10-31 23:37:07 +0300 |
commit | 45b890f7689eb0aba454fc5831d2d79763781677 (patch) | |
tree | 71ab007123eaedd8553d570d6411dfde1062748e /Documentation/virt/kvm/api.rst | |
parent | be47941980d56238455eb54401c7b3de4ac5e269 (diff) | |
parent | 123f42f0ad6815014f54d0cc6eb9039c46ee2907 (diff) | |
download | linux-45b890f7689eb0aba454fc5831d2d79763781677.tar.xz |
Merge tag 'kvmarm-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 6.7
- Generalized infrastructure for 'writable' ID registers, effectively
allowing userspace to opt-out of certain vCPU features for its guest
- Optimization for vSGI injection, opportunistically compressing MPIDR
to vCPU mapping into a table
- Improvements to KVM's PMU emulation, allowing userspace to select
the number of PMCs available to a VM
- Guest support for memory operation instructions (FEAT_MOPS)
- Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
bugs and getting rid of useless code
- Changes to the way the SMCCC filter is constructed, avoiding wasted
memory allocations when not in use
- Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing
the overhead of errata mitigations
- Miscellaneous kernel and selftest fixes
Diffstat (limited to 'Documentation/virt/kvm/api.rst')
-rw-r--r-- | Documentation/virt/kvm/api.rst | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index e81ab4e171e4..7025b3751027 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -3422,6 +3422,8 @@ return indicates the attribute is implemented. It does not necessarily indicate that the attribute can be read or written in the device's current state. "addr" is ignored. +.. _KVM_ARM_VCPU_INIT: + 4.82 KVM_ARM_VCPU_INIT ---------------------- @@ -6140,6 +6142,56 @@ writes to the CNTVCT_EL0 and CNTPCT_EL0 registers using the SET_ONE_REG interface. No error will be returned, but the resulting offset will not be applied. +.. _KVM_ARM_GET_REG_WRITABLE_MASKS: + +4.139 KVM_ARM_GET_REG_WRITABLE_MASKS +------------------------------------------- + +:Capability: KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES +:Architectures: arm64 +:Type: vm ioctl +:Parameters: struct reg_mask_range (in/out) +:Returns: 0 on success, < 0 on error + + +:: + + #define KVM_ARM_FEATURE_ID_RANGE 0 + #define KVM_ARM_FEATURE_ID_RANGE_SIZE (3 * 8 * 8) + + struct reg_mask_range { + __u64 addr; /* Pointer to mask array */ + __u32 range; /* Requested range */ + __u32 reserved[13]; + }; + +This ioctl copies the writable masks for a selected range of registers to +userspace. + +The ``addr`` field is a pointer to the destination array where KVM copies +the writable masks. + +The ``range`` field indicates the requested range of registers. +``KVM_CHECK_EXTENSION`` for the ``KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES`` +capability returns the supported ranges, expressed as a set of flags. Each +flag's bit index represents a possible value for the ``range`` field. +All other values are reserved for future use and KVM may return an error. + +The ``reserved[13]`` array is reserved for future use and should be 0, or +KVM may return an error. + +KVM_ARM_FEATURE_ID_RANGE (0) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The Feature ID range is defined as the AArch64 System register space with +op0==3, op1=={0, 1, 3}, CRn==0, CRm=={0-7}, op2=={0-7}. + +The mask returned array pointed to by ``addr`` is indexed by the macro +``ARM64_FEATURE_ID_RANGE_IDX(op0, op1, crn, crm, op2)``, allowing userspace +to know what fields can be changed for the system register described by +``op0, op1, crn, crm, op2``. KVM rejects ID register values that describe a +superset of the features supported by the system. + 5. The kvm_run structure ======================== |