diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/vhe')
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/Makefile | 11 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/debug-sr.c | 26 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/switch.c | 246 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 114 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/timer-sr.c | 12 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/tlb.c | 163 |
6 files changed, 572 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/vhe/Makefile b/arch/arm64/kvm/hyp/vhe/Makefile new file mode 100644 index 000000000..96bec0ecf --- /dev/null +++ b/arch/arm64/kvm/hyp/vhe/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for Kernel-based Virtual Machine module, HYP/nVHE part +# + +asflags-y := -D__KVM_VHE_HYPERVISOR__ +ccflags-y := -D__KVM_VHE_HYPERVISOR__ + +obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o +obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ + ../fpsimd.o ../hyp-entry.o ../exception.o diff --git a/arch/arm64/kvm/hyp/vhe/debug-sr.c b/arch/arm64/kvm/hyp/vhe/debug-sr.c new file mode 100644 index 000000000..289689b26 --- /dev/null +++ b/arch/arm64/kvm/hyp/vhe/debug-sr.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/debug-sr.h> + +#include <linux/kvm_host.h> + +#include <asm/kvm_hyp.h> + +void __debug_switch_to_guest(struct kvm_vcpu *vcpu) +{ + __debug_switch_to_guest_common(vcpu); +} + +void __debug_switch_to_host(struct kvm_vcpu *vcpu) +{ + __debug_switch_to_host_common(vcpu); +} + +u64 __kvm_get_mdcr_el2(void) +{ + return read_sysreg(mdcr_el2); +} diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c new file mode 100644 index 000000000..45ac4a59c --- /dev/null +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/switch.h> + +#include <linux/arm-smccc.h> +#include <linux/kvm_host.h> +#include <linux/types.h> +#include <linux/jump_label.h> +#include <linux/percpu.h> +#include <uapi/linux/psci.h> + +#include <kvm/arm_psci.h> + +#include <asm/barrier.h> +#include <asm/cpufeature.h> +#include <asm/kprobes.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/fpsimd.h> +#include <asm/debug-monitors.h> +#include <asm/processor.h> +#include <asm/thread_info.h> +#include <asm/vectors.h> + +/* VHE specific context */ +DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data); +DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); +DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); + +static void __activate_traps(struct kvm_vcpu *vcpu) +{ + u64 val; + + ___activate_traps(vcpu); + + val = read_sysreg(cpacr_el1); + val |= CPACR_EL1_TTA; + val &= ~(CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN | + CPACR_EL1_SMEN_EL0EN | CPACR_EL1_SMEN_EL1EN); + + /* + * With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to + * CPTR_EL2. In general, CPACR_EL1 has the same layout as CPTR_EL2, + * except for some missing controls, such as TAM. + * In this case, CPTR_EL2.TAM has the same position with or without + * VHE (HCR.E2H == 1) which allows us to use here the CPTR_EL2.TAM + * shift value for trapping the AMU accesses. + */ + + val |= CPTR_EL2_TAM; + + if (guest_owns_fp_regs(vcpu)) { + if (vcpu_has_sve(vcpu)) + val |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN; + } else { + val &= ~(CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN); + __activate_traps_fpsimd32(vcpu); + } + + write_sysreg(val, cpacr_el1); + + write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el1); +} +NOKPROBE_SYMBOL(__activate_traps); + +static void __deactivate_traps(struct kvm_vcpu *vcpu) +{ + const char *host_vectors = vectors; + + ___deactivate_traps(vcpu); + + write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); + + /* + * ARM errata 1165522 and 1530923 require the actual execution of the + * above before we can switch to the EL2/EL0 translation regime used by + * the host. + */ + asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT)); + + write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1); + + if (!arm64_kernel_unmapped_at_el0()) + host_vectors = __this_cpu_read(this_cpu_vector); + write_sysreg(host_vectors, vbar_el1); +} +NOKPROBE_SYMBOL(__deactivate_traps); + +void activate_traps_vhe_load(struct kvm_vcpu *vcpu) +{ + __activate_traps_common(vcpu); +} + +void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu) +{ + __deactivate_traps_common(vcpu); +} + +static const exit_handler_fn hyp_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = NULL, + [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, + [ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg, + [ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, + [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, + [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, + [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low, + [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, +}; + +static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu) +{ + return hyp_exit_handlers; +} + +static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) +{ +} + +/* Switch to the guest for VHE systems running in EL2 */ +static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + u64 exit_code; + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt->__hyp_running_vcpu = vcpu; + guest_ctxt = &vcpu->arch.ctxt; + + sysreg_save_host_state_vhe(host_ctxt); + + /* + * ARM erratum 1165522 requires us to configure both stage 1 and + * stage 2 translation for the guest context before we clear + * HCR_EL2.TGE. + * + * We have already configured the guest's stage 1 translation in + * kvm_vcpu_load_sysregs_vhe above. We must now call + * __load_stage2 before __activate_traps, because + * __load_stage2 configures stage 2 translation, and + * __activate_traps clear HCR_EL2.TGE (among other things). + */ + __load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch); + __activate_traps(vcpu); + + __kvm_adjust_pc(vcpu); + + sysreg_restore_guest_state_vhe(guest_ctxt); + __debug_switch_to_guest(vcpu); + + do { + /* Jump in the fire! */ + exit_code = __guest_enter(vcpu); + + /* And we're baaack! */ + } while (fixup_guest_exit(vcpu, &exit_code)); + + sysreg_save_guest_state_vhe(guest_ctxt); + + __deactivate_traps(vcpu); + + sysreg_restore_host_state_vhe(host_ctxt); + + if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) + __fpsimd_save_fpexc32(vcpu); + + __debug_switch_to_host(vcpu); + + return exit_code; +} +NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe); + +int __kvm_vcpu_run(struct kvm_vcpu *vcpu) +{ + int ret; + + local_daif_mask(); + + /* + * Having IRQs masked via PMR when entering the guest means the GIC + * will not signal the CPU of interrupts of lower priority, and the + * only way to get out will be via guest exceptions. + * Naturally, we want to avoid this. + * + * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a + * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU. + */ + pmr_sync(); + + ret = __kvm_vcpu_run_vhe(vcpu); + + /* + * local_daif_restore() takes care to properly restore PSTATE.DAIF + * and the GIC PMR if the host is using IRQ priorities. + */ + local_daif_restore(DAIF_PROCCTX_NOIRQ); + + /* + * When we exit from the guest we change a number of CPU configuration + * parameters, such as traps. Make sure these changes take effect + * before running the host or additional guests. + */ + isb(); + + return ret; +} + +static void __hyp_call_panic(u64 spsr, u64 elr, u64 par) +{ + struct kvm_cpu_context *host_ctxt; + struct kvm_vcpu *vcpu; + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + vcpu = host_ctxt->__hyp_running_vcpu; + + __deactivate_traps(vcpu); + sysreg_restore_host_state_vhe(host_ctxt); + + panic("HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n", + spsr, elr, + read_sysreg_el2(SYS_ESR), read_sysreg_el2(SYS_FAR), + read_sysreg(hpfar_el2), par, vcpu); +} +NOKPROBE_SYMBOL(__hyp_call_panic); + +void __noreturn hyp_panic(void) +{ + u64 spsr = read_sysreg_el2(SYS_SPSR); + u64 elr = read_sysreg_el2(SYS_ELR); + u64 par = read_sysreg_par(); + + __hyp_call_panic(spsr, elr, par); + unreachable(); +} + +asmlinkage void kvm_unexpected_el2_exception(void) +{ + __kvm_unexpected_el2_exception(); +} diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c new file mode 100644 index 000000000..7b44f6b3b --- /dev/null +++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c @@ -0,0 +1,114 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/sysreg-sr.h> + +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/kprobes.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> + +/* + * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and + * pstate, which are handled as part of the el2 return state) on every + * switch (sp_el0 is being dealt with in the assembly code). + * tpidr_el0 and tpidrro_el0 only need to be switched when going + * to host userspace or a different VCPU. EL1 registers only need to be + * switched when potentially going to run a different VCPU. The latter two + * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put. + */ + +void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_save_common_state(ctxt); +} +NOKPROBE_SYMBOL(sysreg_save_host_state_vhe); + +void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_save_common_state(ctxt); + __sysreg_save_el2_return_state(ctxt); +} +NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe); + +void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_restore_common_state(ctxt); +} +NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe); + +void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_restore_common_state(ctxt); + __sysreg_restore_el2_return_state(ctxt); +} +NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe); + +/** + * kvm_vcpu_load_sysregs_vhe - Load guest system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Load system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_load() function + * and loading system register state early avoids having to load them on + * every entry to the VM. + */ +void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; + struct kvm_cpu_context *host_ctxt; + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + __sysreg_save_user_state(host_ctxt); + + /* + * Load guest EL1 and user state + * + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + */ + __sysreg32_restore_state(vcpu); + __sysreg_restore_user_state(guest_ctxt); + __sysreg_restore_el1_state(guest_ctxt); + + vcpu_set_flag(vcpu, SYSREGS_ON_CPU); + + activate_traps_vhe_load(vcpu); +} + +/** + * kvm_vcpu_put_sysregs_vhe - Restore host system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Save guest system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_put() function + * and deferring saving system register state until we're no longer running the + * VCPU avoids having to save them on every exit from the VM. + */ +void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; + struct kvm_cpu_context *host_ctxt; + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + deactivate_traps_vhe_put(vcpu); + + __sysreg_save_el1_state(guest_ctxt); + __sysreg_save_user_state(guest_ctxt); + __sysreg32_save_state(vcpu); + + /* Restore host user state */ + __sysreg_restore_user_state(host_ctxt); + + vcpu_clear_flag(vcpu, SYSREGS_ON_CPU); +} diff --git a/arch/arm64/kvm/hyp/vhe/timer-sr.c b/arch/arm64/kvm/hyp/vhe/timer-sr.c new file mode 100644 index 000000000..4cda674a8 --- /dev/null +++ b/arch/arm64/kvm/hyp/vhe/timer-sr.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <asm/kvm_hyp.h> + +void __kvm_timer_set_cntvoff(u64 cntvoff) +{ + write_sysreg(cntvoff, cntvoff_el2); +} diff --git a/arch/arm64/kvm/hyp/vhe/tlb.c b/arch/arm64/kvm/hyp/vhe/tlb.c new file mode 100644 index 000000000..24cef9b87 --- /dev/null +++ b/arch/arm64/kvm/hyp/vhe/tlb.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <linux/irqflags.h> + +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/tlbflush.h> + +struct tlb_inv_context { + unsigned long flags; + u64 tcr; + u64 sctlr; +}; + +static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu, + struct tlb_inv_context *cxt) +{ + u64 val; + + local_irq_save(cxt->flags); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + /* + * For CPUs that are affected by ARM errata 1165522 or 1530923, + * we cannot trust stage-1 to be in a correct state at that + * point. Since we do not want to force a full load of the + * vcpu state, we prevent the EL1 page-table walker to + * allocate new TLBs. This is done by setting the EPD bits + * in the TCR_EL1 register. We also need to prevent it to + * allocate IPA->PA walks, so we enable the S1 MMU... + */ + val = cxt->tcr = read_sysreg_el1(SYS_TCR); + val |= TCR_EPD1_MASK | TCR_EPD0_MASK; + write_sysreg_el1(val, SYS_TCR); + val = cxt->sctlr = read_sysreg_el1(SYS_SCTLR); + val |= SCTLR_ELx_M; + write_sysreg_el1(val, SYS_SCTLR); + } + + /* + * With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and + * most TLB operations target EL2/EL0. In order to affect the + * guest TLBs (EL1/EL0), we need to change one of these two + * bits. Changing E2H is impossible (goodbye TTBR1_EL2), so + * let's flip TGE before executing the TLB operation. + * + * ARM erratum 1165522 requires some special handling (again), + * as we need to make sure both stages of translation are in + * place before clearing TGE. __load_stage2() already + * has an ISB in order to deal with this. + */ + __load_stage2(mmu, mmu->arch); + val = read_sysreg(hcr_el2); + val &= ~HCR_TGE; + write_sysreg(val, hcr_el2); + isb(); +} + +static void __tlb_switch_to_host(struct tlb_inv_context *cxt) +{ + /* + * We're done with the TLB operation, let's restore the host's + * view of HCR_EL2. + */ + write_sysreg(0, vttbr_el2); + write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); + isb(); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + /* Restore the registers to what they were */ + write_sysreg_el1(cxt->tcr, SYS_TCR); + write_sysreg_el1(cxt->sctlr, SYS_SCTLR); + } + + local_irq_restore(cxt->flags); +} + +void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, + phys_addr_t ipa, int level) +{ + struct tlb_inv_context cxt; + + dsb(ishst); + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + /* + * We could do so much better if we had the VA as well. + * Instead, we invalidate Stage-2 for this IPA, and the + * whole of Stage-1. Weep... + */ + ipa >>= 12; + __tlbi_level(ipas2e1is, ipa, level); + + /* + * We have to ensure completion of the invalidation at Stage-2, + * since a table walk on another CPU could refill a TLB with a + * complete (S1 + S2) walk based on the old Stage-2 mapping if + * the Stage-1 invalidation happened first. + */ + dsb(ish); + __tlbi(vmalle1is); + dsb(ish); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + dsb(ishst); + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + __tlbi(vmalls12e1is); + dsb(ish); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + __tlbi(vmalle1); + asm volatile("ic iallu"); + dsb(nsh); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_vm_context(void) +{ + dsb(ishst); + __tlbi(alle1is); + + /* + * VIPT and PIPT caches are not affected by VMID, so no maintenance + * is necessary across a VMID rollover. + * + * VPIPT caches constrain lookup and maintenance to the active VMID, + * so we need to invalidate lines with a stale VMID to avoid an ABA + * race after multiple rollovers. + * + */ + if (icache_is_vpipt()) + asm volatile("ic ialluis"); + + dsb(ish); +} |