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

   1 /*
   2  * Copyright (C) 2015 - ARM Ltd
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/linkage.h>
  19
  20 #include <asm/alternative.h>
  21 #include <asm/assembler.h>
  22 #include <asm/cpufeature.h>
  23 #include <asm/kvm_arm.h>
  24 #include <asm/kvm_asm.h>
  25 #include <asm/kvm_mmu.h>
  26
  27         .text
  28         .pushsection    .hyp.text, "ax"
  29
  30 .macro  save_x0_to_x3
  31         stp     x0, x1, [sp, #-16]!
  32         stp     x2, x3, [sp, #-16]!
  33 .endm
  34
  35 .macro  restore_x0_to_x3
  36         ldp     x2, x3, [sp], #16
  37         ldp     x0, x1, [sp], #16
  38 .endm
  39
  40 .macro do_el2_call
  41         /*
  42          * Shuffle the parameters before calling the function
  43          * pointed to in x0. Assumes parameters in x[1,2,3].
  44          */
  45         mov     lr, x0
  46         mov     x0, x1
  47         mov     x1, x2
  48         mov     x2, x3
  49         blr     lr
  50 .endm
  51
  52 ENTRY(__vhe_hyp_call)
  53         str     lr, [sp, #-16]!
  54         do_el2_call
  55         ldr     lr, [sp], #16
  56         /*
  57          * We used to rely on having an exception return to get
  58          * an implicit isb. In the E2H case, we don't have it anymore.
  59          * rather than changing all the leaf functions, just do it here
  60          * before returning to the rest of the kernel.
  61          */
  62         isb
  63         ret
  64 ENDPROC(__vhe_hyp_call)
  65
  66 el1_sync:                               // Guest trapped into EL2
  67         save_x0_to_x3
  68
  69 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
  70         mrs     x1, esr_el2
  71 alternative_else
  72         mrs     x1, esr_el1
  73 alternative_endif
  74         lsr     x2, x1, #ESR_ELx_EC_SHIFT
  75
  76         cmp     x2, #ESR_ELx_EC_HVC64
  77         b.ne    el1_trap
  78
  79         mrs     x3, vttbr_el2           // If vttbr is valid, the 64bit guest
  80         cbnz    x3, el1_trap            // called HVC
  81
  82         /* Here, we're pretty sure the host called HVC. */
  83         restore_x0_to_x3
  84
  85         cmp     x0, #HVC_GET_VECTORS
  86         b.ne    1f
  87         mrs     x0, vbar_el2
  88         b       2f
  89
  90 1:
  91         /*
  92          * Perform the EL2 call
  93          */
  94         kern_hyp_va     x0
  95         do_el2_call
  96
  97 2:      eret
  98
  99 el1_trap:
 100         /*
 101          * x1: ESR
 102          * x2: ESR_EC
 103          */
 104
 105         /* Guest accessed VFP/SIMD registers, save host, restore Guest */
 106         cmp     x2, #ESR_ELx_EC_FP_ASIMD
 107         b.eq    __fpsimd_guest_restore
 108
 109         mrs     x0, tpidr_el2
 110         mov     x1, #ARM_EXCEPTION_TRAP
 111         b       __guest_exit
 112
 113 el1_irq:
 114         save_x0_to_x3
 115         mrs     x0, tpidr_el2
 116         mov     x1, #ARM_EXCEPTION_IRQ
 117         b       __guest_exit
 118
 119 ENTRY(__hyp_do_panic)
 120         mov     lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
 121                       PSR_MODE_EL1h)
 122         msr     spsr_el2, lr
 123         ldr     lr, =panic
 124         msr     elr_el2, lr
 125         eret
 126 ENDPROC(__hyp_do_panic)
 127
 128 .macro invalid_vector   label, target = __hyp_panic
 129         .align  2
 130 \label:
 131         b \target
 132 ENDPROC(\label)
 133 .endm
 134
 135         /* None of these should ever happen */
 136         invalid_vector  el2t_sync_invalid
 137         invalid_vector  el2t_irq_invalid
 138         invalid_vector  el2t_fiq_invalid
 139         invalid_vector  el2t_error_invalid
 140         invalid_vector  el2h_sync_invalid
 141         invalid_vector  el2h_irq_invalid
 142         invalid_vector  el2h_fiq_invalid
 143         invalid_vector  el2h_error_invalid
 144         invalid_vector  el1_sync_invalid
 145         invalid_vector  el1_irq_invalid
 146         invalid_vector  el1_fiq_invalid
 147         invalid_vector  el1_error_invalid
 148
 149         .ltorg
 150
 151         .align 11
 152
 153 ENTRY(__kvm_hyp_vector)
 154         ventry  el2t_sync_invalid               // Synchronous EL2t
 155         ventry  el2t_irq_invalid                // IRQ EL2t
 156         ventry  el2t_fiq_invalid                // FIQ EL2t
 157         ventry  el2t_error_invalid              // Error EL2t
 158
 159         ventry  el2h_sync_invalid               // Synchronous EL2h
 160         ventry  el2h_irq_invalid                // IRQ EL2h
 161         ventry  el2h_fiq_invalid                // FIQ EL2h
 162         ventry  el2h_error_invalid              // Error EL2h
 163
 164         ventry  el1_sync                        // Synchronous 64-bit EL1
 165         ventry  el1_irq                         // IRQ 64-bit EL1
 166         ventry  el1_fiq_invalid                 // FIQ 64-bit EL1
 167         ventry  el1_error_invalid               // Error 64-bit EL1
 168
 169         ventry  el1_sync                        // Synchronous 32-bit EL1
 170         ventry  el1_irq                         // IRQ 32-bit EL1
 171         ventry  el1_fiq_invalid                 // FIQ 32-bit EL1
 172         ventry  el1_error_invalid               // Error 32-bit EL1
 173 ENDPROC(__kvm_hyp_vector)