This series implements support for allowing KVM guests to use the Arm Scalable Vector Extension (SVE), superseding the previous v5 series [1]. The patches are also available on a branch for reviewer convenience. [2] The patches are based on v5.1-rc1. The series has been reworked to remove the dependency on [3], eliminating the ABI "fixes" but keeping the relevant cleanup/ refactoring. (See patch 16.) This series addresses review comments received on v5, and contains one significant change: * A new ioctl KVM_ARM_VCPU_FINALIZE is added to replace the implicit finalization behaviour in v5. If userspace enables SVE, it must now use this ioctl to finalize the vcpu configuration before KVM_RUN etc. or SVE register access are permitted. For a description of minor updates, see the individual patches. Known issues: * This update requires modifications to kvmtool that are not published yet. I will reply to this cover letter with a link when those are available (hopefully within 24 hours of this posting). The kvmtool branch referenced by the v5 cover letter **will not work** with v6... Please be patient :) Testing status: * Lightweight testing on the Arm Fast Model, primarily to exercise the new vcpu finalization API. I plan to re-run stress testing once v6 is posted. The low-level context switch internals in the series remain unchanged since v5, so it is "relatively unlikely" that new problems will crop up since the v5 testing. * ThunderX2: basic testing of arm64 defconfig, including booting guests (no SVE support on this hardware). (This was done on an interim release candidate of v6: I will redo it after this posting.) * aarch32 host testing has only been done in v5 so far. arch/arm changes between v5 and v6 are minimal. I plan to redo sanity-check testing after this posting. I will reply to this cover letter when I have v6 test outcomes to report. Resolved issues: * The register zeroing bug observed when testing v5 has been tracked down to architecture noncompliance in the Arm Fast Model, which led to lanes of SVE registers being zeroed in some inappropriate situations. [1] Previous series: [PATCH v5 00/26] KVM: arm64: SVE guest support https://lists.cs.columbia.edu/pipermail/kvmarm/2019-February/034695.html [2] This series in git: http://linux-arm.org/git?p=linux-dm.git;a=shortlog;h=refs/heads/sve-kvm/v6/head git://linux-arm.org/linux-dm.git sve-kvm/v6/head [3] [PATCH v2 0/2] Fix KVM_GET_REG_LIST invalid register ID regression https://lists.cs.columbia.edu/pipermail/kvmarm/2018-December/033810.html Dave Martin (27): KVM: Documentation: Document arm64 core registers in detail 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 #includes to kvm_host.h arm64/sve: Clarify role of the VQ map maintenance functions 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: Support runtime sysreg visibility filtering 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: Add missing #include of <linux/string.h> in guest.c KVM: arm64: Factor out core register ID enumeration KVM: arm64: Reject ioctl access to FPSIMD V-regs on SVE vcpus 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: arm/arm64: Add hook for arch-specific KVM initialisation KVM: arm/arm64: Add KVM_ARM_VCPU_FINALIZE ioctl KVM: arm64/sve: Add pseudo-register for the guest's vector lengths KVM: arm64/sve: Allow userspace to enable SVE for vcpus KVM: arm64: Add a capability to advertise SVE support KVM: Document errors for KVM_GET_ONE_REG and KVM_SET_ONE_REG KVM: arm64/sve: Document KVM API extensions for SVE Documentation/virtual/kvm/api.txt | 156 +++++++++++++++ arch/arm/include/asm/kvm_host.h | 6 + arch/arm64/include/asm/fpsimd.h | 33 +++- arch/arm64/include/asm/kvm_host.h | 43 ++++- arch/arm64/include/asm/kvm_hyp.h | 1 - arch/arm64/include/asm/sysreg.h | 3 + arch/arm64/include/uapi/asm/kvm.h | 22 +++ arch/arm64/kernel/cpufeature.c | 2 +- arch/arm64/kernel/fpsimd.c | 172 ++++++++++++----- arch/arm64/kernel/signal.c | 5 - arch/arm64/kvm/fpsimd.c | 17 +- arch/arm64/kvm/guest.c | 387 +++++++++++++++++++++++++++++++++++--- arch/arm64/kvm/hyp/switch.c | 74 ++++++-- arch/arm64/kvm/reset.c | 137 +++++++++++++- arch/arm64/kvm/sys_regs.c | 130 +++++++++++-- arch/arm64/kvm/sys_regs.h | 25 +++ include/uapi/linux/kvm.h | 5 + virt/kvm/arm/arm.c | 22 +++ 18 files changed, 1110 insertions(+), 130 deletions(-) -- 2.1.4 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
