This series enables SVE support for KVM on nVHE hardware (or more likely, software models), and is an alternative to Daniel's patch[1] which has gone through 3 versions, but still has a number of issues. Instead of waiting for things to happen, I decided to try and see what I could come up with. The SVE save/restore is modelled after the SVE VHE flow, itself closely following the FPSIMD flow: - the guest traps to EL2 on first SVE access, and will not trap anymore until vcpu_put() - ZCR_EL2 stays constant as long as the guest has SVE enabled - on vcpu_put(), ZCR_EL2 is restored to the default value Most of this series only repaints things so that VHE and nVHE look as similar as possible, the ZCR_EL2 management being the most visible exception. This results in a bunch of preparatory patches that aim at making the code slightly more readable. This has been tested on a FVP model with both VHE.nVHE configurations using the string tests included with the "optimized-routines" library[2]. Patches against 5.12-rc2. [1] https://lore.kernel.org/r/20210302164850.3553701-1-daniel.kiss@xxxxxxx [2] https://github.com/ARM-software/optimized-routines Daniel Kiss (1): KVM: arm64: Enable SVE support for nVHE Marc Zyngier (9): KVM: arm64: Provide KVM's own save/restore SVE primitives KVM: arm64: Use {read,write}_sysreg_el1 to access ZCR_EL1 KVM: arm64: Let vcpu_sve_pffr() handle HYP VAs KVM: arm64: Introduce vcpu_sve_vq() helper KVM: arm64: Rework SVE host-save/guest-restore KVM: arm64: Map SVE context at EL2 when available KVM: arm64: Save guest's ZCR_EL1 before saving the FPSIMD state KVM: arm64: Add a nVHE-specific SVE VQ reset hypercall KVM: arm64: Save/restore SVE state for nVHE arch/arm64/Kconfig | 7 --- arch/arm64/include/asm/fpsimdmacros.h | 10 +++- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/include/asm/kvm_host.h | 25 +++----- arch/arm64/include/asm/kvm_hyp.h | 2 + arch/arm64/kvm/arm.c | 5 -- arch/arm64/kvm/fpsimd.c | 31 ++++++++-- arch/arm64/kvm/guest.c | 6 +- arch/arm64/kvm/hyp/fpsimd.S | 10 ++++ arch/arm64/kvm/hyp/include/hyp/switch.h | 78 ++++++++++++------------- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 8 +++ arch/arm64/kvm/hyp/nvhe/switch.c | 4 +- arch/arm64/kvm/reset.c | 4 -- 13 files changed, 107 insertions(+), 84 deletions(-) -- 2.29.2
