/* SPDX-License-Identifier: GPL-2.0-only */ /* * Hypervisor stub * * Copyright (C) 2012 ARM Ltd. * Author: Marc Zyngier */ #include #include #include #include #include #include #include #include .text .pushsection .hyp.text, "ax" .align 11 SYM_CODE_START(__hyp_stub_vectors) ventry el2_sync_invalid // Synchronous EL2t ventry el2_irq_invalid // IRQ EL2t ventry el2_fiq_invalid // FIQ EL2t ventry el2_error_invalid // Error EL2t ventry elx_sync // Synchronous EL2h ventry el2_irq_invalid // IRQ EL2h ventry el2_fiq_invalid // FIQ EL2h ventry el2_error_invalid // Error EL2h ventry elx_sync // Synchronous 64-bit EL1 ventry el1_irq_invalid // IRQ 64-bit EL1 ventry el1_fiq_invalid // FIQ 64-bit EL1 ventry el1_error_invalid // Error 64-bit EL1 ventry el1_sync_invalid // Synchronous 32-bit EL1 ventry el1_irq_invalid // IRQ 32-bit EL1 ventry el1_fiq_invalid // FIQ 32-bit EL1 ventry el1_error_invalid // Error 32-bit EL1 SYM_CODE_END(__hyp_stub_vectors) .align 11 SYM_CODE_START_LOCAL(elx_sync) cmp x0, #HVC_SET_VECTORS b.ne 1f msr vbar_el2, x1 b 9f 1: cmp x0, #HVC_VHE_RESTART b.eq mutate_to_vhe 2: cmp x0, #HVC_SOFT_RESTART b.ne 3f mov x0, x2 mov x2, x4 mov x4, x1 mov x1, x3 br x4 // no return 3: cmp x0, #HVC_RESET_VECTORS beq 9f // Nothing to reset! /* Someone called kvm_call_hyp() against the hyp-stub... */ mov_q x0, HVC_STUB_ERR eret 9: mov x0, xzr eret SYM_CODE_END(elx_sync) // nVHE? No way! Give me the real thing! SYM_CODE_START_LOCAL(mutate_to_vhe) // Sanity check: MMU *must* be off mrs x1, sctlr_el2 tbnz x1, #0, 1f // Needs to be VHE capable, obviously mrs x1, id_aa64mmfr1_el1 ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4 cbz x1, 1f // Check whether VHE is disabled from the command line adr_l x1, id_aa64mmfr1_override ldr x2, [x1, FTR_OVR_VAL_OFFSET] ldr x1, [x1, FTR_OVR_MASK_OFFSET] ubfx x2, x2, #ID_AA64MMFR1_VHE_SHIFT, #4 ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4 cmp x1, xzr and x2, x2, x1 csinv x2, x2, xzr, ne cbnz x2, 2f 1: mov_q x0, HVC_STUB_ERR eret 2: // Engage the VHE magic! mov_q x0, HCR_HOST_VHE_FLAGS msr hcr_el2, x0 isb // Use the EL1 allocated stack, per-cpu offset mrs x0, sp_el1 mov sp, x0 mrs x0, tpidr_el1 msr tpidr_el2, x0 // FP configuration, vectors mrs_s x0, SYS_CPACR_EL12 msr cpacr_el1, x0 mrs_s x0, SYS_VBAR_EL12 msr vbar_el1, x0 // Use EL2 translations for SPE & TRBE and disable access from EL1 mrs x0, mdcr_el2 bic x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT) bic x0, x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT) msr mdcr_el2, x0 // Transfer the MM state from EL1 to EL2 mrs_s x0, SYS_TCR_EL12 msr tcr_el1, x0 mrs_s x0, SYS_TTBR0_EL12 msr ttbr0_el1, x0 mrs_s x0, SYS_TTBR1_EL12 msr ttbr1_el1, x0 mrs_s x0, SYS_MAIR_EL12 msr mair_el1, x0 isb // Hack the exception return to stay at EL2 mrs x0, spsr_el1 and x0, x0, #~PSR_MODE_MASK mov x1, #PSR_MODE_EL2h orr x0, x0, x1 msr spsr_el1, x0 b enter_vhe SYM_CODE_END(mutate_to_vhe) // At the point where we reach enter_vhe(), we run with // the MMU off (which is enforced by mutate_to_vhe()). // We thus need to be in the idmap, or everything will // explode when enabling the MMU. .pushsection .idmap.text, "ax" SYM_CODE_START_LOCAL(enter_vhe) // Invalidate TLBs before enabling the MMU tlbi vmalle1 dsb nsh isb // Enable the EL2 S1 MMU, as set up from EL1 mrs_s x0, SYS_SCTLR_EL12 set_sctlr_el1 x0 // Disable the EL1 S1 MMU for a good measure mov_q x0, INIT_SCTLR_EL1_MMU_OFF msr_s SYS_SCTLR_EL12, x0 mov x0, xzr eret SYM_CODE_END(enter_vhe) .popsection .macro invalid_vector label SYM_CODE_START_LOCAL(\label) b \label SYM_CODE_END(\label) .endm invalid_vector el2_sync_invalid invalid_vector el2_irq_invalid invalid_vector el2_fiq_invalid invalid_vector el2_error_invalid invalid_vector el1_sync_invalid invalid_vector el1_irq_invalid invalid_vector el1_fiq_invalid invalid_vector el1_error_invalid .popsection /* * __hyp_set_vectors: Call this after boot to set the initial hypervisor * vectors as part of hypervisor installation. On an SMP system, this should * be called on each CPU. * * x0 must be the physical address of the new vector table, and must be * 2KB aligned. * * Before calling this, you must check that the stub hypervisor is installed * everywhere, by waiting for any secondary CPUs to be brought up and then * checking that is_hyp_mode_available() is true. * * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or * something else went wrong... in such cases, trying to install a new * hypervisor is unlikely to work as desired. * * When you call into your shiny new hypervisor, sp_el2 will contain junk, * so you will need to set that to something sensible at the new hypervisor's * initialisation entry point. */ SYM_FUNC_START(__hyp_set_vectors) mov x1, x0 mov x0, #HVC_SET_VECTORS hvc #0 ret SYM_FUNC_END(__hyp_set_vectors) SYM_FUNC_START(__hyp_reset_vectors) mov x0, #HVC_RESET_VECTORS hvc #0 ret SYM_FUNC_END(__hyp_reset_vectors) /* * Entry point to switch to VHE if deemed capable */ SYM_FUNC_START(switch_to_vhe) // Need to have booted at EL2 adr_l x1, __boot_cpu_mode ldr w0, [x1] cmp w0, #BOOT_CPU_MODE_EL2 b.ne 1f // and still be at EL1 mrs x0, CurrentEL cmp x0, #CurrentEL_EL1 b.ne 1f // Turn the world upside down mov x0, #HVC_VHE_RESTART hvc #0 1: ret SYM_FUNC_END(switch_to_vhe)