[RFC PATCH v2 00/23] KVM: arm64: Initial support for SVE guests
Dave.Martin at arm.com
Fri Sep 28 06:39:04 PDT 2018
This series implements basic support for allowing KVM guests to use the
Arm Scalable Vector Extension (SVE).
The patches are based on v4.19-rc5.
The patches are also available on a branch for reviewer convenience. 
This is a significant overhaul of the previous preliminary series ,
with the major changes outlined below, and additional minor updates in
response to review feedback (see the individual patches for those).
In the interest of getting this series out for review,
This series is **completely untested**.
Reviewers should focus on the proposed API (but any other comments are
of course welcome!)
* Reworked on top of the new KVM FPSIMD context switching model.
* Migrated away from use of feature bits in KVM_ARM_PREFERRED_TARGET /
KVM_VCPU_INIT to detect and enable SVE support.
Availability is now reported via KVM_CAP_ARM_SVE, and SVE support
is enabled and configured per-vcpu with a new ioctl
* KVM_ARM_SVE_CONFIG also adds the ability to detect and configure
the set of SVE vector lengths provided to the guest.
* The ioctl register access model has been simplified. The new SVE
interface must now be used to access the content of the FPSIMD
V-registers, on SVE-enabled vcpus. The kernel no longer tries to
emulate the KVM_REG_ARM_CORE view for these registers in this case.
(For non-SVE-enabled vcpus, the KVM_REG_ARM_CORE interface works as
* Draft documentation for the SVE extensions has been added to KVM's
* KVM_GET_REG_LIST enumerates the FPSIMD V-registers for SVE-enabled
vcpus. It shouldn't, because attempts to access these will now fail!
* kvmtool/qemu updates are needed to enable creation of SVE-enabled
guests (to be discussed separately).
* Due to heavy rework, the series is currently a bit of a mess: the
patches are not presented in a very coherent order, and one or two
patches may even now be redundant or irrelevant. If you spot any
obvious inconsistencies, please shout!
 [RFC PATCH 00/16] KVM: arm64: Initial support for SVE guests
Dave Martin (23):
arm64: fpsimd: Always set TIF_FOREIGN_FPSTATE on task state flush
KVM: arm64: Delete orphaned declaration for __fpsimd_enabled()
KVM: arm64: Refactor kvm_arm_num_regs() for easier maintenance
KVM: arm64: Add missing #include of <linux/bitmap.h> to kvm_host.h
KVM: arm: Add arch vcpu uninit hook
arm64/sve: Check SVE virtualisability
arm64/sve: Enable SVE state tracking for non-task contexts
KVM: arm64: Add a vcpu flag to control SVE visibility for the guest
KVM: arm64: Propagate vcpu into read_id_reg()
KVM: arm64: Extend reset_unknown() to handle mixed RES0/UNKNOWN
KVM: arm64: Support runtime sysreg filtering for KVM_GET_REG_LIST
KVM: arm64/sve: System register context switch and access support
KVM: arm64/sve: Context switch the SVE registers
KVM: Allow 2048-bit register access via ioctl interface
KVM: arm64/sve: Add SVE support to register access ioctl interface
KVM: arm64: Enumerate SVE register indices for KVM_GET_REG_LIST
arm64/sve: In-kernel vector length availability query interface
KVM: arm64: Add arch vcpu ioctl hook
KVM: arm64/sve: Report and enable SVE API extensions for userspace
KVM: arm64: Add arch vm ioctl hook
KVM: arm64/sve: allow KVM_ARM_SVE_CONFIG_QUERY on vm fd
KVM: Documentation: Document arm64 core registers in detail
KVM: arm64/sve: Document KVM API extensions for SVE
Documentation/virtual/kvm/api.txt | 160 ++++++++++++++++
arch/arm/include/asm/kvm_host.h | 16 +-
arch/arm64/include/asm/fpsimd.h | 33 +++-
arch/arm64/include/asm/kvm_host.h | 25 ++-
arch/arm64/include/asm/kvm_hyp.h | 1 -
arch/arm64/include/asm/sysreg.h | 3 +
arch/arm64/include/uapi/asm/kvm.h | 24 +++
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/fpsimd.c | 163 +++++++++++-----
arch/arm64/kernel/signal.c | 5 -
arch/arm64/kvm/fpsimd.c | 16 +-
arch/arm64/kvm/guest.c | 391 ++++++++++++++++++++++++++++++++++++--
arch/arm64/kvm/hyp/switch.c | 69 +++++--
arch/arm64/kvm/reset.c | 50 +++++
arch/arm64/kvm/sys_regs.c | 144 ++++++++++++--
arch/arm64/kvm/sys_regs.h | 8 +-
include/uapi/linux/kvm.h | 5 +
virt/kvm/arm/arm.c | 9 +-
18 files changed, 1016 insertions(+), 108 deletions(-)
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