linux_dsm_epyc7002/arch/arm64/kvm/hyp.S
Marc Zyngier d329de0933 arm64: KVM: enable trapping of all debug registers
Enable trapping of the debug registers, preventing the guests to
mess with the host state (and allowing guests to use the debug
infrastructure as well).

Reviewed-by: Anup Patel <anup.patel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11 04:57:46 -07:00

1275 lines
26 KiB
ArmAsm

/*
* Copyright (C) 2012,2013 - 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/assembler.h>
#include <asm/memory.h>
#include <asm/asm-offsets.h>
#include <asm/debug-monitors.h>
#include <asm/fpsimdmacros.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_arm.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)
#define CPU_SPSR_OFFSET(x) CPU_GP_REG_OFFSET(CPU_SPSR + 8*x)
#define CPU_SYSREG_OFFSET(x) (CPU_SYSREGS + 8*x)
.text
.pushsection .hyp.text, "ax"
.align PAGE_SHIFT
.macro save_common_regs
// x2: base address for cpu context
// x3: tmp register
add x3, x2, #CPU_XREG_OFFSET(19)
stp x19, x20, [x3]
stp x21, x22, [x3, #16]
stp x23, x24, [x3, #32]
stp x25, x26, [x3, #48]
stp x27, x28, [x3, #64]
stp x29, lr, [x3, #80]
mrs x19, sp_el0
mrs x20, elr_el2 // EL1 PC
mrs x21, spsr_el2 // EL1 pstate
stp x19, x20, [x3, #96]
str x21, [x3, #112]
mrs x22, sp_el1
mrs x23, elr_el1
mrs x24, spsr_el1
str x22, [x2, #CPU_GP_REG_OFFSET(CPU_SP_EL1)]
str x23, [x2, #CPU_GP_REG_OFFSET(CPU_ELR_EL1)]
str x24, [x2, #CPU_SPSR_OFFSET(KVM_SPSR_EL1)]
.endm
.macro restore_common_regs
// x2: base address for cpu context
// x3: tmp register
ldr x22, [x2, #CPU_GP_REG_OFFSET(CPU_SP_EL1)]
ldr x23, [x2, #CPU_GP_REG_OFFSET(CPU_ELR_EL1)]
ldr x24, [x2, #CPU_SPSR_OFFSET(KVM_SPSR_EL1)]
msr sp_el1, x22
msr elr_el1, x23
msr spsr_el1, x24
add x3, x2, #CPU_XREG_OFFSET(31) // SP_EL0
ldp x19, x20, [x3]
ldr x21, [x3, #16]
msr sp_el0, x19
msr elr_el2, x20 // EL1 PC
msr spsr_el2, x21 // EL1 pstate
add x3, x2, #CPU_XREG_OFFSET(19)
ldp x19, x20, [x3]
ldp x21, x22, [x3, #16]
ldp x23, x24, [x3, #32]
ldp x25, x26, [x3, #48]
ldp x27, x28, [x3, #64]
ldp x29, lr, [x3, #80]
.endm
.macro save_host_regs
save_common_regs
.endm
.macro restore_host_regs
restore_common_regs
.endm
.macro save_fpsimd
// x2: cpu context address
// x3, x4: tmp regs
add x3, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
fpsimd_save x3, 4
.endm
.macro restore_fpsimd
// x2: cpu context address
// x3, x4: tmp regs
add x3, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
fpsimd_restore x3, 4
.endm
.macro save_guest_regs
// x0 is the vcpu address
// x1 is the return code, do not corrupt!
// x2 is the cpu context
// x3 is a tmp register
// Guest's x0-x3 are on the stack
// Compute base to save registers
add x3, x2, #CPU_XREG_OFFSET(4)
stp x4, x5, [x3]
stp x6, x7, [x3, #16]
stp x8, x9, [x3, #32]
stp x10, x11, [x3, #48]
stp x12, x13, [x3, #64]
stp x14, x15, [x3, #80]
stp x16, x17, [x3, #96]
str x18, [x3, #112]
pop x6, x7 // x2, x3
pop x4, x5 // x0, x1
add x3, x2, #CPU_XREG_OFFSET(0)
stp x4, x5, [x3]
stp x6, x7, [x3, #16]
save_common_regs
.endm
.macro restore_guest_regs
// x0 is the vcpu address.
// x2 is the cpu context
// x3 is a tmp register
// Prepare x0-x3 for later restore
add x3, x2, #CPU_XREG_OFFSET(0)
ldp x4, x5, [x3]
ldp x6, x7, [x3, #16]
push x4, x5 // Push x0-x3 on the stack
push x6, x7
// x4-x18
ldp x4, x5, [x3, #32]
ldp x6, x7, [x3, #48]
ldp x8, x9, [x3, #64]
ldp x10, x11, [x3, #80]
ldp x12, x13, [x3, #96]
ldp x14, x15, [x3, #112]
ldp x16, x17, [x3, #128]
ldr x18, [x3, #144]
// x19-x29, lr, sp*, elr*, spsr*
restore_common_regs
// Last bits of the 64bit state
pop x2, x3
pop x0, x1
// Do not touch any register after this!
.endm
/*
* Macros to perform system register save/restore.
*
* Ordering here is absolutely critical, and must be kept consistent
* in {save,restore}_sysregs, {save,restore}_guest_32bit_state,
* and in kvm_asm.h.
*
* In other words, don't touch any of these unless you know what
* you are doing.
*/
.macro save_sysregs
// x2: base address for cpu context
// x3: tmp register
add x3, x2, #CPU_SYSREG_OFFSET(MPIDR_EL1)
mrs x4, vmpidr_el2
mrs x5, csselr_el1
mrs x6, sctlr_el1
mrs x7, actlr_el1
mrs x8, cpacr_el1
mrs x9, ttbr0_el1
mrs x10, ttbr1_el1
mrs x11, tcr_el1
mrs x12, esr_el1
mrs x13, afsr0_el1
mrs x14, afsr1_el1
mrs x15, far_el1
mrs x16, mair_el1
mrs x17, vbar_el1
mrs x18, contextidr_el1
mrs x19, tpidr_el0
mrs x20, tpidrro_el0
mrs x21, tpidr_el1
mrs x22, amair_el1
mrs x23, cntkctl_el1
mrs x24, par_el1
mrs x25, mdscr_el1
stp x4, x5, [x3]
stp x6, x7, [x3, #16]
stp x8, x9, [x3, #32]
stp x10, x11, [x3, #48]
stp x12, x13, [x3, #64]
stp x14, x15, [x3, #80]
stp x16, x17, [x3, #96]
stp x18, x19, [x3, #112]
stp x20, x21, [x3, #128]
stp x22, x23, [x3, #144]
stp x24, x25, [x3, #160]
.endm
.macro save_debug
// x2: base address for cpu context
// x3: tmp register
mrs x26, id_aa64dfr0_el1
ubfx x24, x26, #12, #4 // Extract BRPs
ubfx x25, x26, #20, #4 // Extract WRPs
mov w26, #15
sub w24, w26, w24 // How many BPs to skip
sub w25, w26, w25 // How many WPs to skip
add x3, x2, #CPU_SYSREG_OFFSET(DBGBCR0_EL1)
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
mrs x20, dbgbcr15_el1
mrs x19, dbgbcr14_el1
mrs x18, dbgbcr13_el1
mrs x17, dbgbcr12_el1
mrs x16, dbgbcr11_el1
mrs x15, dbgbcr10_el1
mrs x14, dbgbcr9_el1
mrs x13, dbgbcr8_el1
mrs x12, dbgbcr7_el1
mrs x11, dbgbcr6_el1
mrs x10, dbgbcr5_el1
mrs x9, dbgbcr4_el1
mrs x8, dbgbcr3_el1
mrs x7, dbgbcr2_el1
mrs x6, dbgbcr1_el1
mrs x5, dbgbcr0_el1
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
str x20, [x3, #(15 * 8)]
str x19, [x3, #(14 * 8)]
str x18, [x3, #(13 * 8)]
str x17, [x3, #(12 * 8)]
str x16, [x3, #(11 * 8)]
str x15, [x3, #(10 * 8)]
str x14, [x3, #(9 * 8)]
str x13, [x3, #(8 * 8)]
str x12, [x3, #(7 * 8)]
str x11, [x3, #(6 * 8)]
str x10, [x3, #(5 * 8)]
str x9, [x3, #(4 * 8)]
str x8, [x3, #(3 * 8)]
str x7, [x3, #(2 * 8)]
str x6, [x3, #(1 * 8)]
str x5, [x3, #(0 * 8)]
add x3, x2, #CPU_SYSREG_OFFSET(DBGBVR0_EL1)
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
mrs x20, dbgbvr15_el1
mrs x19, dbgbvr14_el1
mrs x18, dbgbvr13_el1
mrs x17, dbgbvr12_el1
mrs x16, dbgbvr11_el1
mrs x15, dbgbvr10_el1
mrs x14, dbgbvr9_el1
mrs x13, dbgbvr8_el1
mrs x12, dbgbvr7_el1
mrs x11, dbgbvr6_el1
mrs x10, dbgbvr5_el1
mrs x9, dbgbvr4_el1
mrs x8, dbgbvr3_el1
mrs x7, dbgbvr2_el1
mrs x6, dbgbvr1_el1
mrs x5, dbgbvr0_el1
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
str x20, [x3, #(15 * 8)]
str x19, [x3, #(14 * 8)]
str x18, [x3, #(13 * 8)]
str x17, [x3, #(12 * 8)]
str x16, [x3, #(11 * 8)]
str x15, [x3, #(10 * 8)]
str x14, [x3, #(9 * 8)]
str x13, [x3, #(8 * 8)]
str x12, [x3, #(7 * 8)]
str x11, [x3, #(6 * 8)]
str x10, [x3, #(5 * 8)]
str x9, [x3, #(4 * 8)]
str x8, [x3, #(3 * 8)]
str x7, [x3, #(2 * 8)]
str x6, [x3, #(1 * 8)]
str x5, [x3, #(0 * 8)]
add x3, x2, #CPU_SYSREG_OFFSET(DBGWCR0_EL1)
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
mrs x20, dbgwcr15_el1
mrs x19, dbgwcr14_el1
mrs x18, dbgwcr13_el1
mrs x17, dbgwcr12_el1
mrs x16, dbgwcr11_el1
mrs x15, dbgwcr10_el1
mrs x14, dbgwcr9_el1
mrs x13, dbgwcr8_el1
mrs x12, dbgwcr7_el1
mrs x11, dbgwcr6_el1
mrs x10, dbgwcr5_el1
mrs x9, dbgwcr4_el1
mrs x8, dbgwcr3_el1
mrs x7, dbgwcr2_el1
mrs x6, dbgwcr1_el1
mrs x5, dbgwcr0_el1
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
str x20, [x3, #(15 * 8)]
str x19, [x3, #(14 * 8)]
str x18, [x3, #(13 * 8)]
str x17, [x3, #(12 * 8)]
str x16, [x3, #(11 * 8)]
str x15, [x3, #(10 * 8)]
str x14, [x3, #(9 * 8)]
str x13, [x3, #(8 * 8)]
str x12, [x3, #(7 * 8)]
str x11, [x3, #(6 * 8)]
str x10, [x3, #(5 * 8)]
str x9, [x3, #(4 * 8)]
str x8, [x3, #(3 * 8)]
str x7, [x3, #(2 * 8)]
str x6, [x3, #(1 * 8)]
str x5, [x3, #(0 * 8)]
add x3, x2, #CPU_SYSREG_OFFSET(DBGWVR0_EL1)
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
mrs x20, dbgwvr15_el1
mrs x19, dbgwvr14_el1
mrs x18, dbgwvr13_el1
mrs x17, dbgwvr12_el1
mrs x16, dbgwvr11_el1
mrs x15, dbgwvr10_el1
mrs x14, dbgwvr9_el1
mrs x13, dbgwvr8_el1
mrs x12, dbgwvr7_el1
mrs x11, dbgwvr6_el1
mrs x10, dbgwvr5_el1
mrs x9, dbgwvr4_el1
mrs x8, dbgwvr3_el1
mrs x7, dbgwvr2_el1
mrs x6, dbgwvr1_el1
mrs x5, dbgwvr0_el1
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
str x20, [x3, #(15 * 8)]
str x19, [x3, #(14 * 8)]
str x18, [x3, #(13 * 8)]
str x17, [x3, #(12 * 8)]
str x16, [x3, #(11 * 8)]
str x15, [x3, #(10 * 8)]
str x14, [x3, #(9 * 8)]
str x13, [x3, #(8 * 8)]
str x12, [x3, #(7 * 8)]
str x11, [x3, #(6 * 8)]
str x10, [x3, #(5 * 8)]
str x9, [x3, #(4 * 8)]
str x8, [x3, #(3 * 8)]
str x7, [x3, #(2 * 8)]
str x6, [x3, #(1 * 8)]
str x5, [x3, #(0 * 8)]
mrs x21, mdccint_el1
str x21, [x2, #CPU_SYSREG_OFFSET(MDCCINT_EL1)]
.endm
.macro restore_sysregs
// x2: base address for cpu context
// x3: tmp register
add x3, x2, #CPU_SYSREG_OFFSET(MPIDR_EL1)
ldp x4, x5, [x3]
ldp x6, x7, [x3, #16]
ldp x8, x9, [x3, #32]
ldp x10, x11, [x3, #48]
ldp x12, x13, [x3, #64]
ldp x14, x15, [x3, #80]
ldp x16, x17, [x3, #96]
ldp x18, x19, [x3, #112]
ldp x20, x21, [x3, #128]
ldp x22, x23, [x3, #144]
ldp x24, x25, [x3, #160]
msr vmpidr_el2, x4
msr csselr_el1, x5
msr sctlr_el1, x6
msr actlr_el1, x7
msr cpacr_el1, x8
msr ttbr0_el1, x9
msr ttbr1_el1, x10
msr tcr_el1, x11
msr esr_el1, x12
msr afsr0_el1, x13
msr afsr1_el1, x14
msr far_el1, x15
msr mair_el1, x16
msr vbar_el1, x17
msr contextidr_el1, x18
msr tpidr_el0, x19
msr tpidrro_el0, x20
msr tpidr_el1, x21
msr amair_el1, x22
msr cntkctl_el1, x23
msr par_el1, x24
msr mdscr_el1, x25
.endm
.macro restore_debug
// x2: base address for cpu context
// x3: tmp register
mrs x26, id_aa64dfr0_el1
ubfx x24, x26, #12, #4 // Extract BRPs
ubfx x25, x26, #20, #4 // Extract WRPs
mov w26, #15
sub w24, w26, w24 // How many BPs to skip
sub w25, w26, w25 // How many WPs to skip
add x3, x2, #CPU_SYSREG_OFFSET(DBGBCR0_EL1)
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
ldr x20, [x3, #(15 * 8)]
ldr x19, [x3, #(14 * 8)]
ldr x18, [x3, #(13 * 8)]
ldr x17, [x3, #(12 * 8)]
ldr x16, [x3, #(11 * 8)]
ldr x15, [x3, #(10 * 8)]
ldr x14, [x3, #(9 * 8)]
ldr x13, [x3, #(8 * 8)]
ldr x12, [x3, #(7 * 8)]
ldr x11, [x3, #(6 * 8)]
ldr x10, [x3, #(5 * 8)]
ldr x9, [x3, #(4 * 8)]
ldr x8, [x3, #(3 * 8)]
ldr x7, [x3, #(2 * 8)]
ldr x6, [x3, #(1 * 8)]
ldr x5, [x3, #(0 * 8)]
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
msr dbgbcr15_el1, x20
msr dbgbcr14_el1, x19
msr dbgbcr13_el1, x18
msr dbgbcr12_el1, x17
msr dbgbcr11_el1, x16
msr dbgbcr10_el1, x15
msr dbgbcr9_el1, x14
msr dbgbcr8_el1, x13
msr dbgbcr7_el1, x12
msr dbgbcr6_el1, x11
msr dbgbcr5_el1, x10
msr dbgbcr4_el1, x9
msr dbgbcr3_el1, x8
msr dbgbcr2_el1, x7
msr dbgbcr1_el1, x6
msr dbgbcr0_el1, x5
add x3, x2, #CPU_SYSREG_OFFSET(DBGBVR0_EL1)
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
ldr x20, [x3, #(15 * 8)]
ldr x19, [x3, #(14 * 8)]
ldr x18, [x3, #(13 * 8)]
ldr x17, [x3, #(12 * 8)]
ldr x16, [x3, #(11 * 8)]
ldr x15, [x3, #(10 * 8)]
ldr x14, [x3, #(9 * 8)]
ldr x13, [x3, #(8 * 8)]
ldr x12, [x3, #(7 * 8)]
ldr x11, [x3, #(6 * 8)]
ldr x10, [x3, #(5 * 8)]
ldr x9, [x3, #(4 * 8)]
ldr x8, [x3, #(3 * 8)]
ldr x7, [x3, #(2 * 8)]
ldr x6, [x3, #(1 * 8)]
ldr x5, [x3, #(0 * 8)]
adr x26, 1f
add x26, x26, x24, lsl #2
br x26
1:
msr dbgbvr15_el1, x20
msr dbgbvr14_el1, x19
msr dbgbvr13_el1, x18
msr dbgbvr12_el1, x17
msr dbgbvr11_el1, x16
msr dbgbvr10_el1, x15
msr dbgbvr9_el1, x14
msr dbgbvr8_el1, x13
msr dbgbvr7_el1, x12
msr dbgbvr6_el1, x11
msr dbgbvr5_el1, x10
msr dbgbvr4_el1, x9
msr dbgbvr3_el1, x8
msr dbgbvr2_el1, x7
msr dbgbvr1_el1, x6
msr dbgbvr0_el1, x5
add x3, x2, #CPU_SYSREG_OFFSET(DBGWCR0_EL1)
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
ldr x20, [x3, #(15 * 8)]
ldr x19, [x3, #(14 * 8)]
ldr x18, [x3, #(13 * 8)]
ldr x17, [x3, #(12 * 8)]
ldr x16, [x3, #(11 * 8)]
ldr x15, [x3, #(10 * 8)]
ldr x14, [x3, #(9 * 8)]
ldr x13, [x3, #(8 * 8)]
ldr x12, [x3, #(7 * 8)]
ldr x11, [x3, #(6 * 8)]
ldr x10, [x3, #(5 * 8)]
ldr x9, [x3, #(4 * 8)]
ldr x8, [x3, #(3 * 8)]
ldr x7, [x3, #(2 * 8)]
ldr x6, [x3, #(1 * 8)]
ldr x5, [x3, #(0 * 8)]
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
msr dbgwcr15_el1, x20
msr dbgwcr14_el1, x19
msr dbgwcr13_el1, x18
msr dbgwcr12_el1, x17
msr dbgwcr11_el1, x16
msr dbgwcr10_el1, x15
msr dbgwcr9_el1, x14
msr dbgwcr8_el1, x13
msr dbgwcr7_el1, x12
msr dbgwcr6_el1, x11
msr dbgwcr5_el1, x10
msr dbgwcr4_el1, x9
msr dbgwcr3_el1, x8
msr dbgwcr2_el1, x7
msr dbgwcr1_el1, x6
msr dbgwcr0_el1, x5
add x3, x2, #CPU_SYSREG_OFFSET(DBGWVR0_EL1)
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
ldr x20, [x3, #(15 * 8)]
ldr x19, [x3, #(14 * 8)]
ldr x18, [x3, #(13 * 8)]
ldr x17, [x3, #(12 * 8)]
ldr x16, [x3, #(11 * 8)]
ldr x15, [x3, #(10 * 8)]
ldr x14, [x3, #(9 * 8)]
ldr x13, [x3, #(8 * 8)]
ldr x12, [x3, #(7 * 8)]
ldr x11, [x3, #(6 * 8)]
ldr x10, [x3, #(5 * 8)]
ldr x9, [x3, #(4 * 8)]
ldr x8, [x3, #(3 * 8)]
ldr x7, [x3, #(2 * 8)]
ldr x6, [x3, #(1 * 8)]
ldr x5, [x3, #(0 * 8)]
adr x26, 1f
add x26, x26, x25, lsl #2
br x26
1:
msr dbgwvr15_el1, x20
msr dbgwvr14_el1, x19
msr dbgwvr13_el1, x18
msr dbgwvr12_el1, x17
msr dbgwvr11_el1, x16
msr dbgwvr10_el1, x15
msr dbgwvr9_el1, x14
msr dbgwvr8_el1, x13
msr dbgwvr7_el1, x12
msr dbgwvr6_el1, x11
msr dbgwvr5_el1, x10
msr dbgwvr4_el1, x9
msr dbgwvr3_el1, x8
msr dbgwvr2_el1, x7
msr dbgwvr1_el1, x6
msr dbgwvr0_el1, x5
ldr x21, [x2, #CPU_SYSREG_OFFSET(MDCCINT_EL1)]
msr mdccint_el1, x21
.endm
.macro skip_32bit_state tmp, target
// Skip 32bit state if not needed
mrs \tmp, hcr_el2
tbnz \tmp, #HCR_RW_SHIFT, \target
.endm
.macro skip_tee_state tmp, target
// Skip ThumbEE state if not needed
mrs \tmp, id_pfr0_el1
tbz \tmp, #12, \target
.endm
.macro skip_debug_state tmp, target
ldr \tmp, [x0, #VCPU_DEBUG_FLAGS]
tbz \tmp, #KVM_ARM64_DEBUG_DIRTY_SHIFT, \target
.endm
.macro compute_debug_state target
// Compute debug state: If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY
// is set, we do a full save/restore cycle and disable trapping.
add x25, x0, #VCPU_CONTEXT
// Check the state of MDSCR_EL1
ldr x25, [x25, #CPU_SYSREG_OFFSET(MDSCR_EL1)]
and x26, x25, #DBG_MDSCR_KDE
and x25, x25, #DBG_MDSCR_MDE
adds xzr, x25, x26
b.eq 9998f // Nothing to see there
// If any interesting bits was set, we must set the flag
mov x26, #KVM_ARM64_DEBUG_DIRTY
str x26, [x0, #VCPU_DEBUG_FLAGS]
b 9999f // Don't skip restore
9998:
// Otherwise load the flags from memory in case we recently
// trapped
skip_debug_state x25, \target
9999:
.endm
.macro save_guest_32bit_state
skip_32bit_state x3, 1f
add x3, x2, #CPU_SPSR_OFFSET(KVM_SPSR_ABT)
mrs x4, spsr_abt
mrs x5, spsr_und
mrs x6, spsr_irq
mrs x7, spsr_fiq
stp x4, x5, [x3]
stp x6, x7, [x3, #16]
add x3, x2, #CPU_SYSREG_OFFSET(DACR32_EL2)
mrs x4, dacr32_el2
mrs x5, ifsr32_el2
mrs x6, fpexc32_el2
stp x4, x5, [x3]
str x6, [x3, #16]
skip_debug_state x8, 2f
mrs x7, dbgvcr32_el2
str x7, [x3, #24]
2:
skip_tee_state x8, 1f
add x3, x2, #CPU_SYSREG_OFFSET(TEECR32_EL1)
mrs x4, teecr32_el1
mrs x5, teehbr32_el1
stp x4, x5, [x3]
1:
.endm
.macro restore_guest_32bit_state
skip_32bit_state x3, 1f
add x3, x2, #CPU_SPSR_OFFSET(KVM_SPSR_ABT)
ldp x4, x5, [x3]
ldp x6, x7, [x3, #16]
msr spsr_abt, x4
msr spsr_und, x5
msr spsr_irq, x6
msr spsr_fiq, x7
add x3, x2, #CPU_SYSREG_OFFSET(DACR32_EL2)
ldp x4, x5, [x3]
ldr x6, [x3, #16]
msr dacr32_el2, x4
msr ifsr32_el2, x5
msr fpexc32_el2, x6
skip_debug_state x8, 2f
ldr x7, [x3, #24]
msr dbgvcr32_el2, x7
2:
skip_tee_state x8, 1f
add x3, x2, #CPU_SYSREG_OFFSET(TEECR32_EL1)
ldp x4, x5, [x3]
msr teecr32_el1, x4
msr teehbr32_el1, x5
1:
.endm
.macro activate_traps
ldr x2, [x0, #VCPU_HCR_EL2]
msr hcr_el2, x2
ldr x2, =(CPTR_EL2_TTA)
msr cptr_el2, x2
ldr x2, =(1 << 15) // Trap CP15 Cr=15
msr hstr_el2, x2
mrs x2, mdcr_el2
and x2, x2, #MDCR_EL2_HPMN_MASK
orr x2, x2, #(MDCR_EL2_TPM | MDCR_EL2_TPMCR)
orr x2, x2, #(MDCR_EL2_TDRA | MDCR_EL2_TDOSA)
// Check for KVM_ARM64_DEBUG_DIRTY, and set debug to trap
// if not dirty.
ldr x3, [x0, #VCPU_DEBUG_FLAGS]
tbnz x3, #KVM_ARM64_DEBUG_DIRTY_SHIFT, 1f
orr x2, x2, #MDCR_EL2_TDA
1:
msr mdcr_el2, x2
.endm
.macro deactivate_traps
mov x2, #HCR_RW
msr hcr_el2, x2
msr cptr_el2, xzr
msr hstr_el2, xzr
mrs x2, mdcr_el2
and x2, x2, #MDCR_EL2_HPMN_MASK
msr mdcr_el2, x2
.endm
.macro activate_vm
ldr x1, [x0, #VCPU_KVM]
kern_hyp_va x1
ldr x2, [x1, #KVM_VTTBR]
msr vttbr_el2, x2
.endm
.macro deactivate_vm
msr vttbr_el2, xzr
.endm
/*
* Call into the vgic backend for state saving
*/
.macro save_vgic_state
adr x24, __vgic_sr_vectors
ldr x24, [x24, VGIC_SAVE_FN]
kern_hyp_va x24
blr x24
mrs x24, hcr_el2
mov x25, #HCR_INT_OVERRIDE
neg x25, x25
and x24, x24, x25
msr hcr_el2, x24
.endm
/*
* Call into the vgic backend for state restoring
*/
.macro restore_vgic_state
mrs x24, hcr_el2
ldr x25, [x0, #VCPU_IRQ_LINES]
orr x24, x24, #HCR_INT_OVERRIDE
orr x24, x24, x25
msr hcr_el2, x24
adr x24, __vgic_sr_vectors
ldr x24, [x24, #VGIC_RESTORE_FN]
kern_hyp_va x24
blr x24
.endm
.macro save_timer_state
// x0: vcpu pointer
ldr x2, [x0, #VCPU_KVM]
kern_hyp_va x2
ldr w3, [x2, #KVM_TIMER_ENABLED]
cbz w3, 1f
mrs x3, cntv_ctl_el0
and x3, x3, #3
str w3, [x0, #VCPU_TIMER_CNTV_CTL]
bic x3, x3, #1 // Clear Enable
msr cntv_ctl_el0, x3
isb
mrs x3, cntv_cval_el0
str x3, [x0, #VCPU_TIMER_CNTV_CVAL]
1:
// Allow physical timer/counter access for the host
mrs x2, cnthctl_el2
orr x2, x2, #3
msr cnthctl_el2, x2
// Clear cntvoff for the host
msr cntvoff_el2, xzr
.endm
.macro restore_timer_state
// x0: vcpu pointer
// Disallow physical timer access for the guest
// Physical counter access is allowed
mrs x2, cnthctl_el2
orr x2, x2, #1
bic x2, x2, #2
msr cnthctl_el2, x2
ldr x2, [x0, #VCPU_KVM]
kern_hyp_va x2
ldr w3, [x2, #KVM_TIMER_ENABLED]
cbz w3, 1f
ldr x3, [x2, #KVM_TIMER_CNTVOFF]
msr cntvoff_el2, x3
ldr x2, [x0, #VCPU_TIMER_CNTV_CVAL]
msr cntv_cval_el0, x2
isb
ldr w2, [x0, #VCPU_TIMER_CNTV_CTL]
and x2, x2, #3
msr cntv_ctl_el0, x2
1:
.endm
__save_sysregs:
save_sysregs
ret
__restore_sysregs:
restore_sysregs
ret
__save_debug:
save_debug
ret
__restore_debug:
restore_debug
ret
__save_fpsimd:
save_fpsimd
ret
__restore_fpsimd:
restore_fpsimd
ret
/*
* u64 __kvm_vcpu_run(struct kvm_vcpu *vcpu);
*
* This is the world switch. The first half of the function
* deals with entering the guest, and anything from __kvm_vcpu_return
* to the end of the function deals with reentering the host.
* On the enter path, only x0 (vcpu pointer) must be preserved until
* the last moment. On the exit path, x0 (vcpu pointer) and x1 (exception
* code) must both be preserved until the epilogue.
* In both cases, x2 points to the CPU context we're saving/restoring from/to.
*/
ENTRY(__kvm_vcpu_run)
kern_hyp_va x0
msr tpidr_el2, x0 // Save the vcpu register
// Host context
ldr x2, [x0, #VCPU_HOST_CONTEXT]
kern_hyp_va x2
save_host_regs
bl __save_fpsimd
bl __save_sysregs
compute_debug_state 1f
bl __save_debug
1:
activate_traps
activate_vm
restore_vgic_state
restore_timer_state
// Guest context
add x2, x0, #VCPU_CONTEXT
bl __restore_sysregs
bl __restore_fpsimd
skip_debug_state x3, 1f
bl __restore_debug
1:
restore_guest_32bit_state
restore_guest_regs
// That's it, no more messing around.
eret
__kvm_vcpu_return:
// Assume x0 is the vcpu pointer, x1 the return code
// Guest's x0-x3 are on the stack
// Guest context
add x2, x0, #VCPU_CONTEXT
save_guest_regs
bl __save_fpsimd
bl __save_sysregs
skip_debug_state x3, 1f
bl __save_debug
1:
save_guest_32bit_state
save_timer_state
save_vgic_state
deactivate_traps
deactivate_vm
// Host context
ldr x2, [x0, #VCPU_HOST_CONTEXT]
kern_hyp_va x2
bl __restore_sysregs
bl __restore_fpsimd
skip_debug_state x3, 1f
// Clear the dirty flag for the next run, as all the state has
// already been saved. Note that we nuke the whole 64bit word.
// If we ever add more flags, we'll have to be more careful...
str xzr, [x0, #VCPU_DEBUG_FLAGS]
bl __restore_debug
1:
restore_host_regs
mov x0, x1
ret
END(__kvm_vcpu_run)
// void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
ENTRY(__kvm_tlb_flush_vmid_ipa)
dsb ishst
kern_hyp_va x0
ldr x2, [x0, #KVM_VTTBR]
msr vttbr_el2, x2
isb
/*
* We could do so much better if we had the VA as well.
* Instead, we invalidate Stage-2 for this IPA, and the
* whole of Stage-1. Weep...
*/
tlbi ipas2e1is, x1
/*
* We have to ensure completion of the invalidation at Stage-2,
* since a table walk on another CPU could refill a TLB with a
* complete (S1 + S2) walk based on the old Stage-2 mapping if
* the Stage-1 invalidation happened first.
*/
dsb ish
tlbi vmalle1is
dsb ish
isb
msr vttbr_el2, xzr
ret
ENDPROC(__kvm_tlb_flush_vmid_ipa)
ENTRY(__kvm_flush_vm_context)
dsb ishst
tlbi alle1is
ic ialluis
dsb ish
ret
ENDPROC(__kvm_flush_vm_context)
// struct vgic_sr_vectors __vgi_sr_vectors;
.align 3
ENTRY(__vgic_sr_vectors)
.skip VGIC_SR_VECTOR_SZ
ENDPROC(__vgic_sr_vectors)
__kvm_hyp_panic:
// Guess the context by looking at VTTBR:
// If zero, then we're already a host.
// Otherwise restore a minimal host context before panicing.
mrs x0, vttbr_el2
cbz x0, 1f
mrs x0, tpidr_el2
deactivate_traps
deactivate_vm
ldr x2, [x0, #VCPU_HOST_CONTEXT]
kern_hyp_va x2
bl __restore_sysregs
1: adr x0, __hyp_panic_str
adr x1, 2f
ldp x2, x3, [x1]
sub x0, x0, x2
add x0, x0, x3
mrs x1, spsr_el2
mrs x2, elr_el2
mrs x3, esr_el2
mrs x4, far_el2
mrs x5, hpfar_el2
mrs x6, par_el1
mrs x7, tpidr_el2
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
.align 3
2: .quad HYP_PAGE_OFFSET
.quad PAGE_OFFSET
ENDPROC(__kvm_hyp_panic)
__hyp_panic_str:
.ascii "HYP panic:\nPS:%08x PC:%p ESR:%p\nFAR:%p HPFAR:%p PAR:%p\nVCPU:%p\n\0"
.align 2
/*
* u64 kvm_call_hyp(void *hypfn, ...);
*
* This is not really a variadic function in the classic C-way and care must
* be taken when calling this to ensure parameters are passed in registers
* only, since the stack will change between the caller and the callee.
*
* Call the function with the first argument containing a pointer to the
* function you wish to call in Hyp mode, and subsequent arguments will be
* passed as x0, x1, and x2 (a maximum of 3 arguments in addition to the
* function pointer can be passed). The function being called must be mapped
* in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are
* passed in r0 and r1.
*
* A function pointer with a value of 0 has a special meaning, and is
* used to implement __hyp_get_vectors in the same way as in
* arch/arm64/kernel/hyp_stub.S.
*/
ENTRY(kvm_call_hyp)
hvc #0
ret
ENDPROC(kvm_call_hyp)
.macro invalid_vector label, target
.align 2
\label:
b \target
ENDPROC(\label)
.endm
/* None of these should ever happen */
invalid_vector el2t_sync_invalid, __kvm_hyp_panic
invalid_vector el2t_irq_invalid, __kvm_hyp_panic
invalid_vector el2t_fiq_invalid, __kvm_hyp_panic
invalid_vector el2t_error_invalid, __kvm_hyp_panic
invalid_vector el2h_sync_invalid, __kvm_hyp_panic
invalid_vector el2h_irq_invalid, __kvm_hyp_panic
invalid_vector el2h_fiq_invalid, __kvm_hyp_panic
invalid_vector el2h_error_invalid, __kvm_hyp_panic
invalid_vector el1_sync_invalid, __kvm_hyp_panic
invalid_vector el1_irq_invalid, __kvm_hyp_panic
invalid_vector el1_fiq_invalid, __kvm_hyp_panic
invalid_vector el1_error_invalid, __kvm_hyp_panic
el1_sync: // Guest trapped into EL2
push x0, x1
push x2, x3
mrs x1, esr_el2
lsr x2, x1, #ESR_EL2_EC_SHIFT
cmp x2, #ESR_EL2_EC_HVC64
b.ne el1_trap
mrs x3, vttbr_el2 // If vttbr is valid, the 64bit guest
cbnz x3, el1_trap // called HVC
/* Here, we're pretty sure the host called HVC. */
pop x2, x3
pop x0, x1
/* Check for __hyp_get_vectors */
cbnz x0, 1f
mrs x0, vbar_el2
b 2f
1: push lr, xzr
/*
* Compute the function address in EL2, and shuffle the parameters.
*/
kern_hyp_va x0
mov lr, x0
mov x0, x1
mov x1, x2
mov x2, x3
blr lr
pop lr, xzr
2: eret
el1_trap:
/*
* x1: ESR
* x2: ESR_EC
*/
cmp x2, #ESR_EL2_EC_DABT
mov x0, #ESR_EL2_EC_IABT
ccmp x2, x0, #4, ne
b.ne 1f // Not an abort we care about
/* This is an abort. Check for permission fault */
and x2, x1, #ESR_EL2_FSC_TYPE
cmp x2, #FSC_PERM
b.ne 1f // Not a permission fault
/*
* Check for Stage-1 page table walk, which is guaranteed
* to give a valid HPFAR_EL2.
*/
tbnz x1, #7, 1f // S1PTW is set
/* Preserve PAR_EL1 */
mrs x3, par_el1
push x3, xzr
/*
* Permission fault, HPFAR_EL2 is invalid.
* Resolve the IPA the hard way using the guest VA.
* Stage-1 translation already validated the memory access rights.
* As such, we can use the EL1 translation regime, and don't have
* to distinguish between EL0 and EL1 access.
*/
mrs x2, far_el2
at s1e1r, x2
isb
/* Read result */
mrs x3, par_el1
pop x0, xzr // Restore PAR_EL1 from the stack
msr par_el1, x0
tbnz x3, #0, 3f // Bail out if we failed the translation
ubfx x3, x3, #12, #36 // Extract IPA
lsl x3, x3, #4 // and present it like HPFAR
b 2f
1: mrs x3, hpfar_el2
mrs x2, far_el2
2: mrs x0, tpidr_el2
str w1, [x0, #VCPU_ESR_EL2]
str x2, [x0, #VCPU_FAR_EL2]
str x3, [x0, #VCPU_HPFAR_EL2]
mov x1, #ARM_EXCEPTION_TRAP
b __kvm_vcpu_return
/*
* Translation failed. Just return to the guest and
* let it fault again. Another CPU is probably playing
* behind our back.
*/
3: pop x2, x3
pop x0, x1
eret
el1_irq:
push x0, x1
push x2, x3
mrs x0, tpidr_el2
mov x1, #ARM_EXCEPTION_IRQ
b __kvm_vcpu_return
.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 el2h_error_invalid // 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_invalid // 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_invalid // Error 32-bit EL1
ENDPROC(__kvm_hyp_vector)
.popsection