As we progress towards being able to keep guest state private to the host running nVHE hypervisor, this series allows the hypervisor to install itself on newly booted CPUs before the host is allowed to run on them. All functionality described below is opt-in, guarded by an early param 'kvm-arm.protected'. Future patches specific to the new "protected" mode should be hidden behind the same param. The hypervisor starts trapping host SMCs and intercepting host's PSCI CPU_ON/OFF/SUSPEND calls. It replaces the host's entry point with its own, initializes the EL2 state of the new CPU and installs the nVHE hyp vector before ERETing to the host's entry point. The kernel checks new cores' features against the finalized system capabilities. To avoid the need to move this code/data to EL2, the implementation only allows to boot cores that were online at the time of KVM initialization and therefore had been checked already. Other PSCI SMCs are forwarded to EL3, though only the known set of SMCs implemented in the kernel is allowed. Non-PSCI SMCs are also forwarded to EL3. Future changes will need to ensure the safety of all SMCs wrt. private guests. The host is still allowed to reset EL2 back to the stub vector, eg. for hibernation or kexec, but will not disable nVHE when there are no VMs. Tested on Rock Pi 4b, based on 5.10-rc3. changes since rfc: * add early param to make features opt-in * simplify CPU_ON/SUSPEND implementation * replace spinlocks with CAS atomic * make cpu_logical_map ro_after_init -David David Brazdil (24): psci: Accessor for configured PSCI version psci: Accessor for configured PSCI function IDs arm64: Move MAIR_EL1_SET to asm/memory.h kvm: arm64: Initialize MAIR_EL2 using a constant kvm: arm64: Add .hyp.data..ro_after_init ELF section kvm: arm64: Support per_cpu_ptr in nVHE hyp code kvm: arm64: Create nVHE copy of cpu_logical_map kvm: arm64: Move hyp-init params to a per-CPU struct kvm: arm64: Refactor handle_trap to use a switch kvm: arm64: Extract parts of el2_setup into a macro kvm: arm64: Add SMC handler in nVHE EL2 kvm: arm64: Extract __do_hyp_init into a helper function kvm: arm64: Add CPU entry point in nVHE hyp kvm: arm64: Add function to enter host from KVM nVHE hyp code kvm: arm64: Bootstrap PSCI SMC handler in nVHE EL2 kvm: arm64: Add offset for hyp VA <-> PA conversion kvm: arm64: Add __hyp_pa_symbol helper macro kvm: arm64: Forward safe PSCI SMCs coming from host kvm: arm64: Intercept host's PSCI_CPU_ON SMCs kvm: arm64: Intercept host's CPU_SUSPEND PSCI SMCs kvm: arm64: Add kvm-arm.protected early kernel parameter kvm: arm64: Keep nVHE EL2 vector installed kvm: arm64: Trap host SMCs in protected mode. kvm: arm64: Fix EL2 mode availability checks arch/arm64/include/asm/kvm_arm.h | 1 + arch/arm64/include/asm/kvm_asm.h | 136 ++++++++++++++ arch/arm64/include/asm/kvm_hyp.h | 9 + arch/arm64/include/asm/memory.h | 13 ++ arch/arm64/include/asm/percpu.h | 6 + arch/arm64/include/asm/sections.h | 1 + arch/arm64/include/asm/virt.h | 26 +++ arch/arm64/kernel/asm-offsets.c | 5 + arch/arm64/kernel/head.S | 140 ++------------ arch/arm64/kernel/image-vars.h | 7 + arch/arm64/kernel/vmlinux.lds.S | 10 + arch/arm64/kvm/arm.c | 157 ++++++++++++++-- arch/arm64/kvm/hyp/nvhe/Makefile | 3 +- arch/arm64/kvm/hyp/nvhe/host.S | 9 + arch/arm64/kvm/hyp/nvhe/hyp-init.S | 84 +++++++-- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 56 +++++- arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 1 + arch/arm64/kvm/hyp/nvhe/percpu.c | 38 ++++ arch/arm64/kvm/hyp/nvhe/psci.c | 291 +++++++++++++++++++++++++++++ arch/arm64/kvm/hyp/nvhe/switch.c | 5 +- arch/arm64/mm/proc.S | 13 -- drivers/firmware/psci/psci.c | 25 ++- include/linux/psci.h | 18 ++ include/uapi/linux/psci.h | 1 + 24 files changed, 865 insertions(+), 190 deletions(-) create mode 100644 arch/arm64/kvm/hyp/nvhe/percpu.c create mode 100644 arch/arm64/kvm/hyp/nvhe/psci.c -- 2.29.2.222.g5d2a92d10f8-goog _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
