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

161 lines
4.1 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/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/fpsimdmacros.h>
#include <asm/kvm.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
#define CPU_GP_REG_OFFSET(x) (CPU_GP_REGS + x)
#define CPU_XREG_OFFSET(x) CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x)
.text
.pushsection .hyp.text, "ax"
.macro save_callee_saved_regs ctxt
stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
.endm
.macro restore_callee_saved_regs ctxt
ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
.endm
/*
* u64 __guest_enter(struct kvm_vcpu *vcpu,
* struct kvm_cpu_context *host_ctxt);
*/
ENTRY(__guest_enter)
// x0: vcpu
// x1: host/guest context
// x2-x18: clobbered by macros
// Store the host regs
save_callee_saved_regs x1
// Preserve vcpu & host_ctxt for use at exit time
stp x0, x1, [sp, #-16]!
add x1, x0, #VCPU_CONTEXT
// Prepare x0-x1 for later restore by pushing them onto the stack
ldp x2, x3, [x1, #CPU_XREG_OFFSET(0)]
stp x2, x3, [sp, #-16]!
// x2-x18
ldp x2, x3, [x1, #CPU_XREG_OFFSET(2)]
ldp x4, x5, [x1, #CPU_XREG_OFFSET(4)]
ldp x6, x7, [x1, #CPU_XREG_OFFSET(6)]
ldp x8, x9, [x1, #CPU_XREG_OFFSET(8)]
ldp x10, x11, [x1, #CPU_XREG_OFFSET(10)]
ldp x12, x13, [x1, #CPU_XREG_OFFSET(12)]
ldp x14, x15, [x1, #CPU_XREG_OFFSET(14)]
ldp x16, x17, [x1, #CPU_XREG_OFFSET(16)]
ldr x18, [x1, #CPU_XREG_OFFSET(18)]
// x19-x29, lr
restore_callee_saved_regs x1
// Last bits of the 64bit state
ldp x0, x1, [sp], #16
// Do not touch any register after this!
eret
ENDPROC(__guest_enter)
ENTRY(__guest_exit)
// x0: vcpu
// x1: return code
// x2-x3: free
// x4-x29,lr: vcpu regs
// vcpu x0-x3 on the stack
add x2, x0, #VCPU_CONTEXT
stp x4, x5, [x2, #CPU_XREG_OFFSET(4)]
stp x6, x7, [x2, #CPU_XREG_OFFSET(6)]
stp x8, x9, [x2, #CPU_XREG_OFFSET(8)]
stp x10, x11, [x2, #CPU_XREG_OFFSET(10)]
stp x12, x13, [x2, #CPU_XREG_OFFSET(12)]
stp x14, x15, [x2, #CPU_XREG_OFFSET(14)]
stp x16, x17, [x2, #CPU_XREG_OFFSET(16)]
str x18, [x2, #CPU_XREG_OFFSET(18)]
ldp x6, x7, [sp], #16 // x2, x3
ldp x4, x5, [sp], #16 // x0, x1
stp x4, x5, [x2, #CPU_XREG_OFFSET(0)]
stp x6, x7, [x2, #CPU_XREG_OFFSET(2)]
save_callee_saved_regs x2
// Restore vcpu & host_ctxt from the stack
// (preserving return code in x1)
ldp x0, x2, [sp], #16
// Now restore the host regs
restore_callee_saved_regs x2
mov x0, x1
ret
ENDPROC(__guest_exit)
ENTRY(__fpsimd_guest_restore)
stp x4, lr, [sp, #-16]!
mrs x2, cptr_el2
bic x2, x2, #CPTR_EL2_TFP
msr cptr_el2, x2
isb
mrs x3, tpidr_el2
ldr x0, [x3, #VCPU_HOST_CONTEXT]
kern_hyp_va x0
add x0, x0, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
bl __fpsimd_save_state
add x2, x3, #VCPU_CONTEXT
add x0, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
bl __fpsimd_restore_state
// Skip restoring fpexc32 for AArch64 guests
mrs x1, hcr_el2
tbnz x1, #HCR_RW_SHIFT, 1f
ldr x4, [x3, #VCPU_FPEXC32_EL2]
msr fpexc32_el2, x4
1:
ldp x4, lr, [sp], #16
ldp x2, x3, [sp], #16
ldp x0, x1, [sp], #16
eret
ENDPROC(__fpsimd_guest_restore)