linux/arch/arm64/kvm/hyp/hyp-entry.S

204 lines
4.7 KiB
ArmAsm

/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/linkage.h>
#include <asm/alternative.h>
#include <asm/assembler.h>
#include <asm/cpufeature.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
.text
.pushsection .hyp.text, "ax"
.macro do_el2_call
/*
* Shuffle the parameters before calling the function
* pointed to in x0. Assumes parameters in x[1,2,3].
*/
mov lr, x0
mov x0, x1
mov x1, x2
mov x2, x3
blr lr
.endm
ENTRY(__vhe_hyp_call)
str lr, [sp, #-16]!
do_el2_call
ldr lr, [sp], #16
/*
* We used to rely on having an exception return to get
* an implicit isb. In the E2H case, we don't have it anymore.
* rather than changing all the leaf functions, just do it here
* before returning to the rest of the kernel.
*/
isb
ret
ENDPROC(__vhe_hyp_call)
/*
* Compute the idmap address of __kvm_hyp_reset based on the idmap
* start passed as a parameter, and jump there.
*
* x0: HYP phys_idmap_start
*/
ENTRY(__kvm_hyp_teardown)
mov x4, x0
adr_l x3, __kvm_hyp_reset
/* insert __kvm_hyp_reset()s offset into phys_idmap_start */
bfi x4, x3, #0, #PAGE_SHIFT
br x4
ENDPROC(__kvm_hyp_teardown)
el1_sync: // Guest trapped into EL2
stp x0, x1, [sp, #-16]!
alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
mrs x1, esr_el2
alternative_else
mrs x1, esr_el1
alternative_endif
lsr x0, x1, #ESR_ELx_EC_SHIFT
cmp x0, #ESR_ELx_EC_HVC64
b.ne el1_trap
mrs x1, vttbr_el2 // If vttbr is valid, the 64bit guest
cbnz x1, el1_trap // called HVC
/* Here, we're pretty sure the host called HVC. */
ldp x0, x1, [sp], #16
cmp x0, #HVC_GET_VECTORS
b.ne 1f
mrs x0, vbar_el2
b 2f
1:
/*
* Perform the EL2 call
*/
kern_hyp_va x0
do_el2_call
2: eret
el1_trap:
/*
* x0: ESR_EC
*/
/* Guest accessed VFP/SIMD registers, save host, restore Guest */
cmp x0, #ESR_ELx_EC_FP_ASIMD
b.eq __fpsimd_guest_restore
mrs x1, tpidr_el2
mov x0, #ARM_EXCEPTION_TRAP
b __guest_exit
el1_irq:
stp x0, x1, [sp, #-16]!
mrs x1, tpidr_el2
mov x0, #ARM_EXCEPTION_IRQ
b __guest_exit
el1_error:
stp x0, x1, [sp, #-16]!
mrs x1, tpidr_el2
mov x0, #ARM_EXCEPTION_EL1_SERROR
b __guest_exit
el2_error:
/*
* Only two possibilities:
* 1) Either we come from the exit path, having just unmasked
* PSTATE.A: change the return code to an EL2 fault, and
* carry on, as we're already in a sane state to handle it.
* 2) Or we come from anywhere else, and that's a bug: we panic.
*
* For (1), x0 contains the original return code and x1 doesn't
* contain anything meaningful at that stage. We can reuse them
* as temp registers.
* For (2), who cares?
*/
mrs x0, elr_el2
adr x1, abort_guest_exit_start
cmp x0, x1
adr x1, abort_guest_exit_end
ccmp x0, x1, #4, ne
b.ne __hyp_panic
mov x0, #(1 << ARM_EXIT_WITH_SERROR_BIT)
eret
ENTRY(__hyp_do_panic)
mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
PSR_MODE_EL1h)
msr spsr_el2, lr
ldr lr, =panic
msr elr_el2, lr
eret
ENDPROC(__hyp_do_panic)
.macro invalid_vector label, target = __hyp_panic
.align 2
\label:
b \target
ENDPROC(\label)
.endm
/* None of these should ever happen */
invalid_vector el2t_sync_invalid
invalid_vector el2t_irq_invalid
invalid_vector el2t_fiq_invalid
invalid_vector el2t_error_invalid
invalid_vector el2h_sync_invalid
invalid_vector el2h_irq_invalid
invalid_vector el2h_fiq_invalid
invalid_vector el1_sync_invalid
invalid_vector el1_irq_invalid
invalid_vector el1_fiq_invalid
.ltorg
.align 11
ENTRY(__kvm_hyp_vector)
ventry el2t_sync_invalid // Synchronous EL2t
ventry el2t_irq_invalid // IRQ EL2t
ventry el2t_fiq_invalid // FIQ EL2t
ventry el2t_error_invalid // Error EL2t
ventry el2h_sync_invalid // Synchronous EL2h
ventry el2h_irq_invalid // IRQ EL2h
ventry el2h_fiq_invalid // FIQ EL2h
ventry el2_error // Error EL2h
ventry el1_sync // Synchronous 64-bit EL1
ventry el1_irq // IRQ 64-bit EL1
ventry el1_fiq_invalid // FIQ 64-bit EL1
ventry el1_error // Error 64-bit EL1
ventry el1_sync // Synchronous 32-bit EL1
ventry el1_irq // IRQ 32-bit EL1
ventry el1_fiq_invalid // FIQ 32-bit EL1
ventry el1_error // Error 32-bit EL1
ENDPROC(__kvm_hyp_vector)