summaryrefslogtreecommitdiffstats
path: root/arch/arm/kvm/hyp/hyp-entry.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/kvm/hyp/hyp-entry.S')
-rw-r--r--arch/arm/kvm/hyp/hyp-entry.S295
1 files changed, 0 insertions, 295 deletions
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
deleted file mode 100644
index fe3d7811a908..000000000000
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ /dev/null
@@ -1,295 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2012 - Virtual Open Systems and Columbia University
- * Author: Christoffer Dall <c.dall@virtualopensystems.com>
- */
-
-#include <linux/arm-smccc.h>
-#include <linux/linkage.h>
-#include <asm/kvm_arm.h>
-#include <asm/kvm_asm.h>
-
- .arch_extension virt
-
- .text
- .pushsection .hyp.text, "ax"
-
-.macro load_vcpu reg
- mrc p15, 4, \reg, c13, c0, 2 @ HTPIDR
-.endm
-
-/********************************************************************
- * Hypervisor exception vector and handlers
- *
- *
- * The KVM/ARM Hypervisor ABI is defined as follows:
- *
- * Entry to Hyp mode from the host kernel will happen _only_ when an HVC
- * instruction is issued since all traps are disabled when running the host
- * kernel as per the Hyp-mode initialization at boot time.
- *
- * HVC instructions cause a trap to the vector page + offset 0x14 (see hyp_hvc
- * below) when the HVC instruction is called from SVC mode (i.e. a guest or the
- * host kernel) and they cause a trap to the vector page + offset 0x8 when HVC
- * instructions are called from within Hyp-mode.
- *
- * Hyp-ABI: Calling HYP-mode functions from host (in SVC mode):
- * Switching to Hyp mode is done through a simple HVC #0 instruction. The
- * exception vector code will check that the HVC comes from VMID==0.
- * - r0 contains a pointer to a HYP function
- * - r1, r2, and r3 contain arguments to the above function.
- * - The HYP function will be called with its arguments in r0, r1 and r2.
- * On HYP function return, we return directly to SVC.
- *
- * Note that the above is used to execute code in Hyp-mode from a host-kernel
- * point of view, and is a different concept from performing a world-switch and
- * executing guest code SVC mode (with a VMID != 0).
- */
-
- .align 5
-__kvm_hyp_vector:
- .global __kvm_hyp_vector
-
- @ Hyp-mode exception vector
- W(b) hyp_reset
- W(b) hyp_undef
- W(b) hyp_svc
- W(b) hyp_pabt
- W(b) hyp_dabt
- W(b) hyp_hvc
- W(b) hyp_irq
- W(b) hyp_fiq
-
-#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
- .align 5
-__kvm_hyp_vector_ic_inv:
- .global __kvm_hyp_vector_ic_inv
-
- /*
- * We encode the exception entry in the bottom 3 bits of
- * SP, and we have to guarantee to be 8 bytes aligned.
- */
- W(add) sp, sp, #1 /* Reset 7 */
- W(add) sp, sp, #1 /* Undef 6 */
- W(add) sp, sp, #1 /* Syscall 5 */
- W(add) sp, sp, #1 /* Prefetch abort 4 */
- W(add) sp, sp, #1 /* Data abort 3 */
- W(add) sp, sp, #1 /* HVC 2 */
- W(add) sp, sp, #1 /* IRQ 1 */
- W(nop) /* FIQ 0 */
-
- mcr p15, 0, r0, c7, c5, 0 /* ICIALLU */
- isb
-
- b decode_vectors
-
- .align 5
-__kvm_hyp_vector_bp_inv:
- .global __kvm_hyp_vector_bp_inv
-
- /*
- * We encode the exception entry in the bottom 3 bits of
- * SP, and we have to guarantee to be 8 bytes aligned.
- */
- W(add) sp, sp, #1 /* Reset 7 */
- W(add) sp, sp, #1 /* Undef 6 */
- W(add) sp, sp, #1 /* Syscall 5 */
- W(add) sp, sp, #1 /* Prefetch abort 4 */
- W(add) sp, sp, #1 /* Data abort 3 */
- W(add) sp, sp, #1 /* HVC 2 */
- W(add) sp, sp, #1 /* IRQ 1 */
- W(nop) /* FIQ 0 */
-
- mcr p15, 0, r0, c7, c5, 6 /* BPIALL */
- isb
-
-decode_vectors:
-
-#ifdef CONFIG_THUMB2_KERNEL
- /*
- * Yet another silly hack: Use VPIDR as a temp register.
- * Thumb2 is really a pain, as SP cannot be used with most
- * of the bitwise instructions. The vect_br macro ensures
- * things gets cleaned-up.
- */
- mcr p15, 4, r0, c0, c0, 0 /* VPIDR */
- mov r0, sp
- and r0, r0, #7
- sub sp, sp, r0
- push {r1, r2}
- mov r1, r0
- mrc p15, 4, r0, c0, c0, 0 /* VPIDR */
- mrc p15, 0, r2, c0, c0, 0 /* MIDR */
- mcr p15, 4, r2, c0, c0, 0 /* VPIDR */
-#endif
-
-.macro vect_br val, targ
-ARM( eor sp, sp, #\val )
-ARM( tst sp, #7 )
-ARM( eorne sp, sp, #\val )
-
-THUMB( cmp r1, #\val )
-THUMB( popeq {r1, r2} )
-
- beq \targ
-.endm
-
- vect_br 0, hyp_fiq
- vect_br 1, hyp_irq
- vect_br 2, hyp_hvc
- vect_br 3, hyp_dabt
- vect_br 4, hyp_pabt
- vect_br 5, hyp_svc
- vect_br 6, hyp_undef
- vect_br 7, hyp_reset
-#endif
-
-.macro invalid_vector label, cause
- .align
-\label: mov r0, #\cause
- b __hyp_panic
-.endm
-
- invalid_vector hyp_reset ARM_EXCEPTION_RESET
- invalid_vector hyp_undef ARM_EXCEPTION_UNDEFINED
- invalid_vector hyp_svc ARM_EXCEPTION_SOFTWARE
- invalid_vector hyp_pabt ARM_EXCEPTION_PREF_ABORT
- invalid_vector hyp_fiq ARM_EXCEPTION_FIQ
-
-ENTRY(__hyp_do_panic)
- mrs lr, cpsr
- bic lr, lr, #MODE_MASK
- orr lr, lr, #SVC_MODE
-THUMB( orr lr, lr, #PSR_T_BIT )
- msr spsr_cxsf, lr
- ldr lr, =panic
- msr ELR_hyp, lr
- ldr lr, =__kvm_call_hyp
- clrex
- eret
-ENDPROC(__hyp_do_panic)
-
-hyp_hvc:
- /*
- * Getting here is either because of a trap from a guest,
- * or from executing HVC from the host kernel, which means
- * "do something in Hyp mode".
- */
- push {r0, r1, r2}
-
- @ Check syndrome register
- mrc p15, 4, r1, c5, c2, 0 @ HSR
- lsr r0, r1, #HSR_EC_SHIFT
- cmp r0, #HSR_EC_HVC
- bne guest_trap @ Not HVC instr.
-
- /*
- * Let's check if the HVC came from VMID 0 and allow simple
- * switch to Hyp mode
- */
- mrrc p15, 6, r0, r2, c2
- lsr r2, r2, #16
- and r2, r2, #0xff
- cmp r2, #0
- bne guest_hvc_trap @ Guest called HVC
-
- /*
- * Getting here means host called HVC, we shift parameters and branch
- * to Hyp function.
- */
- pop {r0, r1, r2}
-
- /*
- * Check if we have a kernel function, which is guaranteed to be
- * bigger than the maximum hyp stub hypercall
- */
- cmp r0, #HVC_STUB_HCALL_NR
- bhs 1f
-
- /*
- * Not a kernel function, treat it as a stub hypercall.
- * Compute the physical address for __kvm_handle_stub_hvc
- * (as the code lives in the idmaped page) and branch there.
- * We hijack ip (r12) as a tmp register.
- */
- push {r1}
- ldr r1, =kimage_voffset
- ldr r1, [r1]
- ldr ip, =__kvm_handle_stub_hvc
- sub ip, ip, r1
- pop {r1}
-
- bx ip
-
-1:
- /*
- * Pushing r2 here is just a way of keeping the stack aligned to
- * 8 bytes on any path that can trigger a HYP exception. Here,
- * we may well be about to jump into the guest, and the guest
- * exit would otherwise be badly decoded by our fancy
- * "decode-exception-without-a-branch" code...
- */
- push {r2, lr}
-
- mov lr, r0
- mov r0, r1
- mov r1, r2
- mov r2, r3
-
-THUMB( orr lr, #1)
- blx lr @ Call the HYP function
-
- pop {r2, lr}
- eret
-
-guest_hvc_trap:
- movw r2, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
- movt r2, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
- ldr r0, [sp] @ Guest's r0
- teq r0, r2
- bne guest_trap
- add sp, sp, #12
- @ Returns:
- @ r0 = 0
- @ r1 = HSR value (perfectly predictable)
- @ r2 = ARM_SMCCC_ARCH_WORKAROUND_1
- mov r0, #0
- eret
-
-guest_trap:
- load_vcpu r0 @ Load VCPU pointer to r0
-
-#ifdef CONFIG_VFPv3
- @ Check for a VFP access
- lsr r1, r1, #HSR_EC_SHIFT
- cmp r1, #HSR_EC_CP_0_13
- beq __vfp_guest_restore
-#endif
-
- mov r1, #ARM_EXCEPTION_HVC
- b __guest_exit
-
-hyp_irq:
- push {r0, r1, r2}
- mov r1, #ARM_EXCEPTION_IRQ
- load_vcpu r0 @ Load VCPU pointer to r0
- b __guest_exit
-
-hyp_dabt:
- push {r0, r1}
- mrs r0, ELR_hyp
- ldr r1, =abort_guest_exit_start
-THUMB( add r1, r1, #1)
- cmp r0, r1
- ldrne r1, =abort_guest_exit_end
-THUMB( addne r1, r1, #1)
- cmpne r0, r1
- pop {r0, r1}
- bne __hyp_panic
-
- orr r0, r0, #(1 << ARM_EXIT_WITH_ABORT_BIT)
- eret
-
- .ltorg
-
- .popsection