259 lines
5.9 KiB
ArmAsm
259 lines
5.9 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Hypervisor stub
|
|
*
|
|
* Copyright (C) 2012 ARM Ltd.
|
|
* Author: Marc Zyngier <marc.zyngier@arm.com>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/linkage.h>
|
|
|
|
#include <asm/assembler.h>
|
|
#include <asm/el2_setup.h>
|
|
#include <asm/kvm_arm.h>
|
|
#include <asm/kvm_asm.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/virt.h>
|
|
|
|
.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_FINALISE_EL2
|
|
b.eq __finalise_el2
|
|
|
|
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)
|
|
|
|
SYM_CODE_START_LOCAL(__finalise_el2)
|
|
finalise_el2_state
|
|
|
|
// nVHE? No way! Give me the real thing!
|
|
// Sanity check: MMU *must* be off
|
|
mrs x1, sctlr_el2
|
|
tbnz x1, #0, 1f
|
|
|
|
// Needs to be VHE capable, obviously
|
|
check_override id_aa64mmfr1 ID_AA64MMFR1_EL1_VH_SHIFT 0f 1f x1 x2
|
|
|
|
0: // Check whether we only want the hypervisor to run VHE, not the kernel
|
|
adr_l x1, arm64_sw_feature_override
|
|
ldr x2, [x1, FTR_OVR_VAL_OFFSET]
|
|
ldr x1, [x1, FTR_OVR_MASK_OFFSET]
|
|
and x2, x2, x1
|
|
ubfx x2, x2, #ARM64_SW_FEATURE_OVERRIDE_HVHE, #4
|
|
cbz 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
|
|
mrs x1, REG_ID_AA64MMFR3_EL1
|
|
ubfx x1, x1, #ID_AA64MMFR3_EL1_TCRX_SHIFT, #4
|
|
cbz x1, .Lskip_tcr2
|
|
mrs x0, REG_TCR2_EL12
|
|
msr REG_TCR2_EL1, x0
|
|
|
|
// Transfer permission indirection state
|
|
mrs x1, REG_ID_AA64MMFR3_EL1
|
|
ubfx x1, x1, #ID_AA64MMFR3_EL1_S1PIE_SHIFT, #4
|
|
cbz x1, .Lskip_indirection
|
|
mrs x0, REG_PIRE0_EL12
|
|
msr REG_PIRE0_EL1, x0
|
|
mrs x0, REG_PIR_EL12
|
|
msr REG_PIR_EL1, x0
|
|
|
|
.Lskip_indirection:
|
|
.Lskip_tcr2:
|
|
|
|
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(__finalise_el2)
|
|
|
|
// At the point where we reach enter_vhe(), we run with
|
|
// the MMU off (which is enforced by __finalise_el2()).
|
|
// 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 finalise EL2 and switch to VHE if deemed capable
|
|
*
|
|
* w0: boot mode, as returned by init_kernel_el()
|
|
*/
|
|
SYM_FUNC_START(finalise_el2)
|
|
// Need to have booted at EL2
|
|
cmp w0, #BOOT_CPU_MODE_EL2
|
|
b.ne 1f
|
|
|
|
// and still be at EL1
|
|
mrs x0, CurrentEL
|
|
cmp x0, #CurrentEL_EL1
|
|
b.ne 1f
|
|
|
|
mov x0, #HVC_FINALISE_EL2
|
|
hvc #0
|
|
1:
|
|
ret
|
|
SYM_FUNC_END(finalise_el2)
|