| /* |
| * Copyright (C) 2012 - Virtual Open Systems and Columbia University |
| * Author: Christoffer Dall <c.dall@virtualopensystems.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, write to the Free Software |
| * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| */ |
| |
| #include <linux/mm.h> |
| #include <linux/kvm_host.h> |
| #include <asm/kvm_arm.h> |
| #include <asm/kvm_emulate.h> |
| #include <asm/opcodes.h> |
| #include <trace/events/kvm.h> |
| |
| #include "trace.h" |
| |
| #define VCPU_NR_MODES 6 |
| #define VCPU_REG_OFFSET_USR 0 |
| #define VCPU_REG_OFFSET_FIQ 1 |
| #define VCPU_REG_OFFSET_IRQ 2 |
| #define VCPU_REG_OFFSET_SVC 3 |
| #define VCPU_REG_OFFSET_ABT 4 |
| #define VCPU_REG_OFFSET_UND 5 |
| #define REG_OFFSET(_reg) \ |
| (offsetof(struct kvm_regs, _reg) / sizeof(u32)) |
| |
| #define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs.uregs[_num]) |
| |
| static const unsigned long vcpu_reg_offsets[VCPU_NR_MODES][15] = { |
| /* USR/SYS Registers */ |
| [VCPU_REG_OFFSET_USR] = { |
| USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2), |
| USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5), |
| USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8), |
| USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11), |
| USR_REG_OFFSET(12), USR_REG_OFFSET(13), USR_REG_OFFSET(14), |
| }, |
| |
| /* FIQ Registers */ |
| [VCPU_REG_OFFSET_FIQ] = { |
| USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2), |
| USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5), |
| USR_REG_OFFSET(6), USR_REG_OFFSET(7), |
| REG_OFFSET(fiq_regs[0]), /* r8 */ |
| REG_OFFSET(fiq_regs[1]), /* r9 */ |
| REG_OFFSET(fiq_regs[2]), /* r10 */ |
| REG_OFFSET(fiq_regs[3]), /* r11 */ |
| REG_OFFSET(fiq_regs[4]), /* r12 */ |
| REG_OFFSET(fiq_regs[5]), /* r13 */ |
| REG_OFFSET(fiq_regs[6]), /* r14 */ |
| }, |
| |
| /* IRQ Registers */ |
| [VCPU_REG_OFFSET_IRQ] = { |
| USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2), |
| USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5), |
| USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8), |
| USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11), |
| USR_REG_OFFSET(12), |
| REG_OFFSET(irq_regs[0]), /* r13 */ |
| REG_OFFSET(irq_regs[1]), /* r14 */ |
| }, |
| |
| /* SVC Registers */ |
| [VCPU_REG_OFFSET_SVC] = { |
| USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2), |
| USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5), |
| USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8), |
| USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11), |
| USR_REG_OFFSET(12), |
| REG_OFFSET(svc_regs[0]), /* r13 */ |
| REG_OFFSET(svc_regs[1]), /* r14 */ |
| }, |
| |
| /* ABT Registers */ |
| [VCPU_REG_OFFSET_ABT] = { |
| USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2), |
| USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5), |
| USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8), |
| USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11), |
| USR_REG_OFFSET(12), |
| REG_OFFSET(abt_regs[0]), /* r13 */ |
| REG_OFFSET(abt_regs[1]), /* r14 */ |
| }, |
| |
| /* UND Registers */ |
| [VCPU_REG_OFFSET_UND] = { |
| USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2), |
| USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5), |
| USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8), |
| USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11), |
| USR_REG_OFFSET(12), |
| REG_OFFSET(und_regs[0]), /* r13 */ |
| REG_OFFSET(und_regs[1]), /* r14 */ |
| }, |
| }; |
| |
| /* |
| * Return a pointer to the register number valid in the current mode of |
| * the virtual CPU. |
| */ |
| unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num) |
| { |
| unsigned long *reg_array = (unsigned long *)&vcpu->arch.ctxt.gp_regs; |
| unsigned long mode = *vcpu_cpsr(vcpu) & MODE_MASK; |
| |
| switch (mode) { |
| case USR_MODE...SVC_MODE: |
| mode &= ~MODE32_BIT; /* 0 ... 3 */ |
| break; |
| |
| case ABT_MODE: |
| mode = VCPU_REG_OFFSET_ABT; |
| break; |
| |
| case UND_MODE: |
| mode = VCPU_REG_OFFSET_UND; |
| break; |
| |
| case SYSTEM_MODE: |
| mode = VCPU_REG_OFFSET_USR; |
| break; |
| |
| default: |
| BUG(); |
| } |
| |
| return reg_array + vcpu_reg_offsets[mode][reg_num]; |
| } |
| |
| /* |
| * Return the SPSR for the current mode of the virtual CPU. |
| */ |
| unsigned long *vcpu_spsr(struct kvm_vcpu *vcpu) |
| { |
| unsigned long mode = *vcpu_cpsr(vcpu) & MODE_MASK; |
| switch (mode) { |
| case SVC_MODE: |
| return &vcpu->arch.ctxt.gp_regs.KVM_ARM_SVC_spsr; |
| case ABT_MODE: |
| return &vcpu->arch.ctxt.gp_regs.KVM_ARM_ABT_spsr; |
| case UND_MODE: |
| return &vcpu->arch.ctxt.gp_regs.KVM_ARM_UND_spsr; |
| case IRQ_MODE: |
| return &vcpu->arch.ctxt.gp_regs.KVM_ARM_IRQ_spsr; |
| case FIQ_MODE: |
| return &vcpu->arch.ctxt.gp_regs.KVM_ARM_FIQ_spsr; |
| default: |
| BUG(); |
| } |
| } |
| |
| /****************************************************************************** |
| * Inject exceptions into the guest |
| */ |
| |
| static u32 exc_vector_base(struct kvm_vcpu *vcpu) |
| { |
| u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR); |
| u32 vbar = vcpu_cp15(vcpu, c12_VBAR); |
| |
| if (sctlr & SCTLR_V) |
| return 0xffff0000; |
| else /* always have security exceptions */ |
| return vbar; |
| } |
| |
| /* |
| * Switch to an exception mode, updating both CPSR and SPSR. Follow |
| * the logic described in AArch32.EnterMode() from the ARMv8 ARM. |
| */ |
| static void kvm_update_psr(struct kvm_vcpu *vcpu, unsigned long mode) |
| { |
| unsigned long cpsr = *vcpu_cpsr(vcpu); |
| u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR); |
| |
| *vcpu_cpsr(vcpu) = (cpsr & ~MODE_MASK) | mode; |
| |
| switch (mode) { |
| case FIQ_MODE: |
| *vcpu_cpsr(vcpu) |= PSR_F_BIT; |
| /* Fall through */ |
| case ABT_MODE: |
| case IRQ_MODE: |
| *vcpu_cpsr(vcpu) |= PSR_A_BIT; |
| /* Fall through */ |
| default: |
| *vcpu_cpsr(vcpu) |= PSR_I_BIT; |
| } |
| |
| *vcpu_cpsr(vcpu) &= ~(PSR_IT_MASK | PSR_J_BIT | PSR_E_BIT | PSR_T_BIT); |
| |
| if (sctlr & SCTLR_TE) |
| *vcpu_cpsr(vcpu) |= PSR_T_BIT; |
| if (sctlr & SCTLR_EE) |
| *vcpu_cpsr(vcpu) |= PSR_E_BIT; |
| |
| /* Note: These now point to the mode banked copies */ |
| *vcpu_spsr(vcpu) = cpsr; |
| } |
| |
| /** |
| * kvm_inject_undefined - inject an undefined exception into the guest |
| * @vcpu: The VCPU to receive the undefined exception |
| * |
| * It is assumed that this code is called from the VCPU thread and that the |
| * VCPU therefore is not currently executing guest code. |
| * |
| * Modelled after TakeUndefInstrException() pseudocode. |
| */ |
| void kvm_inject_undefined(struct kvm_vcpu *vcpu) |
| { |
| unsigned long cpsr = *vcpu_cpsr(vcpu); |
| bool is_thumb = (cpsr & PSR_T_BIT); |
| u32 vect_offset = 4; |
| u32 return_offset = (is_thumb) ? 2 : 4; |
| |
| kvm_update_psr(vcpu, UND_MODE); |
| *vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) + return_offset; |
| |
| /* Branch to exception vector */ |
| *vcpu_pc(vcpu) = exc_vector_base(vcpu) + vect_offset; |
| } |
| |
| /* |
| * Modelled after TakeDataAbortException() and TakePrefetchAbortException |
| * pseudocode. |
| */ |
| static void inject_abt(struct kvm_vcpu *vcpu, bool is_pabt, unsigned long addr) |
| { |
| u32 vect_offset; |
| u32 return_offset = (is_pabt) ? 4 : 8; |
| bool is_lpae; |
| |
| kvm_update_psr(vcpu, ABT_MODE); |
| *vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) + return_offset; |
| |
| if (is_pabt) |
| vect_offset = 12; |
| else |
| vect_offset = 16; |
| |
| /* Branch to exception vector */ |
| *vcpu_pc(vcpu) = exc_vector_base(vcpu) + vect_offset; |
| |
| if (is_pabt) { |
| /* Set IFAR and IFSR */ |
| vcpu_cp15(vcpu, c6_IFAR) = addr; |
| is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31); |
| /* Always give debug fault for now - should give guest a clue */ |
| if (is_lpae) |
| vcpu_cp15(vcpu, c5_IFSR) = 1 << 9 | 0x22; |
| else |
| vcpu_cp15(vcpu, c5_IFSR) = 2; |
| } else { /* !iabt */ |
| /* Set DFAR and DFSR */ |
| vcpu_cp15(vcpu, c6_DFAR) = addr; |
| is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31); |
| /* Always give debug fault for now - should give guest a clue */ |
| if (is_lpae) |
| vcpu_cp15(vcpu, c5_DFSR) = 1 << 9 | 0x22; |
| else |
| vcpu_cp15(vcpu, c5_DFSR) = 2; |
| } |
| |
| } |
| |
| /** |
| * kvm_inject_dabt - inject a data abort into the guest |
| * @vcpu: The VCPU to receive the undefined exception |
| * @addr: The address to report in the DFAR |
| * |
| * It is assumed that this code is called from the VCPU thread and that the |
| * VCPU therefore is not currently executing guest code. |
| */ |
| void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr) |
| { |
| inject_abt(vcpu, false, addr); |
| } |
| |
| /** |
| * kvm_inject_pabt - inject a prefetch abort into the guest |
| * @vcpu: The VCPU to receive the undefined exception |
| * @addr: The address to report in the DFAR |
| * |
| * It is assumed that this code is called from the VCPU thread and that the |
| * VCPU therefore is not currently executing guest code. |
| */ |
| void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr) |
| { |
| inject_abt(vcpu, true, addr); |
| } |
| |
| /** |
| * kvm_inject_vabt - inject an async abort / SError into the guest |
| * @vcpu: The VCPU to receive the exception |
| * |
| * It is assumed that this code is called from the VCPU thread and that the |
| * VCPU therefore is not currently executing guest code. |
| */ |
| void kvm_inject_vabt(struct kvm_vcpu *vcpu) |
| { |
| vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) | HCR_VA); |
| } |