[PATCH v2 2/7] arm64: KVM: Move the AArch32 conditional execution to common code
From: Marc Zyngier <hidden>
Date: 2016-09-06 08:28:42
Also in:
kvm, kvmarm
Subsystem:
arm port, arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
It would make some sense to share the conditional execution code between 32 and 64bit. In order to achieve this, let's move that code to virt/kvm/arm/aarch32.c. While we're at it, drop a superfluous BUG_ON() that wasn't that useful. Following patches will migrate the 32bit port to that code base. Signed-off-by: Marc Zyngier <redacted> --- arch/arm/kvm/emulate.c | 4 +- arch/arm64/kvm/Makefile | 3 +- arch/arm64/kvm/emulate.c | 148 ----------------------------------------------- virt/kvm/arm/aarch32.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 149 insertions(+), 152 deletions(-) delete mode 100644 arch/arm64/kvm/emulate.c create mode 100644 virt/kvm/arm/aarch32.c
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index af93e3f..eda9ddd 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c@@ -221,9 +221,7 @@ static void kvm_adjust_itstate(struct kvm_vcpu *vcpu) unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_arm = !(cpsr & PSR_T_BIT); - BUG_ON(is_arm && (cpsr & PSR_IT_MASK)); - - if (!(cpsr & PSR_IT_MASK)) + if (is_arm || !(cpsr & PSR_IT_MASK)) return; cond = (cpsr & 0xe000) >> 13;
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 695eb3c..d50a82a 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile@@ -16,9 +16,10 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/e kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/arm.o $(ARM)/mmu.o $(ARM)/mmio.o kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/psci.o $(ARM)/perf.o -kvm-$(CONFIG_KVM_ARM_HOST) += emulate.o inject_fault.o regmap.o +kvm-$(CONFIG_KVM_ARM_HOST) += inject_fault.o regmap.o kvm-$(CONFIG_KVM_ARM_HOST) += hyp.o hyp-init.o handle_exit.o kvm-$(CONFIG_KVM_ARM_HOST) += guest.o debug.o reset.o sys_regs.o sys_regs_generic_v8.o +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/aarch32.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-init.o
diff --git a/arch/arm64/kvm/emulate.c b/arch/arm64/kvm/emulate.c
deleted file mode 100644
index 40098ad..0000000
--- a/arch/arm64/kvm/emulate.c
+++ /dev/null@@ -1,148 +0,0 @@ -/* - * (not much of an) Emulation layer for 32bit guests. - * - * Copyright (C) 2012,2013 - ARM Ltd - * Author: Marc Zyngier <marc.zyngier@arm.com> - * - * based on arch/arm/kvm/emulate.c - * 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, see <http://www.gnu.org/licenses/>. - */ - -#include <linux/kvm_host.h> -#include <asm/kvm_emulate.h> - -/* - * stolen from arch/arm/kernel/opcodes.c - * - * condition code lookup table - * index into the table is test code: EQ, NE, ... LT, GT, AL, NV - * - * bit position in short is condition code: NZCV - */ -static const unsigned short cc_map[16] = { - 0xF0F0, /* EQ == Z set */ - 0x0F0F, /* NE */ - 0xCCCC, /* CS == C set */ - 0x3333, /* CC */ - 0xFF00, /* MI == N set */ - 0x00FF, /* PL */ - 0xAAAA, /* VS == V set */ - 0x5555, /* VC */ - 0x0C0C, /* HI == C set && Z clear */ - 0xF3F3, /* LS == C clear || Z set */ - 0xAA55, /* GE == (N==V) */ - 0x55AA, /* LT == (N!=V) */ - 0x0A05, /* GT == (!Z && (N==V)) */ - 0xF5FA, /* LE == (Z || (N!=V)) */ - 0xFFFF, /* AL always */ - 0 /* NV */ -}; - -/* - * Check if a trapped instruction should have been executed or not. - */ -bool kvm_condition_valid32(const struct kvm_vcpu *vcpu) -{ - unsigned long cpsr; - u32 cpsr_cond; - int cond; - - /* Top two bits non-zero? Unconditional. */ - if (kvm_vcpu_get_hsr(vcpu) >> 30) - return true; - - /* Is condition field valid? */ - cond = kvm_vcpu_get_condition(vcpu); - if (cond == 0xE) - return true; - - cpsr = *vcpu_cpsr(vcpu); - - if (cond < 0) { - /* This can happen in Thumb mode: examine IT state. */ - unsigned long it; - - it = ((cpsr >> 8) & 0xFC) | ((cpsr >> 25) & 0x3); - - /* it == 0 => unconditional. */ - if (it == 0) - return true; - - /* The cond for this insn works out as the top 4 bits. */ - cond = (it >> 4); - } - - cpsr_cond = cpsr >> 28; - - if (!((cc_map[cond] >> cpsr_cond) & 1)) - return false; - - return true; -} - -/** - * adjust_itstate - adjust ITSTATE when emulating instructions in IT-block - * @vcpu: The VCPU pointer - * - * When exceptions occur while instructions are executed in Thumb IF-THEN - * blocks, the ITSTATE field of the CPSR is not advanced (updated), so we have - * to do this little bit of work manually. The fields map like this: - * - * IT[7:0] -> CPSR[26:25],CPSR[15:10] - */ -static void kvm_adjust_itstate(struct kvm_vcpu *vcpu) -{ - unsigned long itbits, cond; - unsigned long cpsr = *vcpu_cpsr(vcpu); - bool is_arm = !(cpsr & COMPAT_PSR_T_BIT); - - BUG_ON(is_arm && (cpsr & COMPAT_PSR_IT_MASK)); - - if (!(cpsr & COMPAT_PSR_IT_MASK)) - return; - - cond = (cpsr & 0xe000) >> 13; - itbits = (cpsr & 0x1c00) >> (10 - 2); - itbits |= (cpsr & (0x3 << 25)) >> 25; - - /* Perform ITAdvance (see page A2-52 in ARM DDI 0406C) */ - if ((itbits & 0x7) == 0) - itbits = cond = 0; - else - itbits = (itbits << 1) & 0x1f; - - cpsr &= ~COMPAT_PSR_IT_MASK; - cpsr |= cond << 13; - cpsr |= (itbits & 0x1c) << (10 - 2); - cpsr |= (itbits & 0x3) << 25; - *vcpu_cpsr(vcpu) = cpsr; -} - -/** - * kvm_skip_instr - skip a trapped instruction and proceed to the next - * @vcpu: The vcpu pointer - */ -void kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr) -{ - bool is_thumb; - - is_thumb = !!(*vcpu_cpsr(vcpu) & COMPAT_PSR_T_BIT); - if (is_thumb && !is_wide_instr) - *vcpu_pc(vcpu) += 2; - else - *vcpu_pc(vcpu) += 4; - kvm_adjust_itstate(vcpu); -}
diff --git a/virt/kvm/arm/aarch32.c b/virt/kvm/arm/aarch32.c
new file mode 100644
index 0000000..cb02e56
--- /dev/null
+++ b/virt/kvm/arm/aarch32.c@@ -0,0 +1,146 @@ +/* + * (not much of an) Emulation layer for 32bit guests. + * + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * based on arch/arm/kvm/emulate.c + * 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, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/kvm_host.h> +#include <asm/kvm_emulate.h> + +/* + * stolen from arch/arm/kernel/opcodes.c + * + * condition code lookup table + * index into the table is test code: EQ, NE, ... LT, GT, AL, NV + * + * bit position in short is condition code: NZCV + */ +static const unsigned short cc_map[16] = { + 0xF0F0, /* EQ == Z set */ + 0x0F0F, /* NE */ + 0xCCCC, /* CS == C set */ + 0x3333, /* CC */ + 0xFF00, /* MI == N set */ + 0x00FF, /* PL */ + 0xAAAA, /* VS == V set */ + 0x5555, /* VC */ + 0x0C0C, /* HI == C set && Z clear */ + 0xF3F3, /* LS == C clear || Z set */ + 0xAA55, /* GE == (N==V) */ + 0x55AA, /* LT == (N!=V) */ + 0x0A05, /* GT == (!Z && (N==V)) */ + 0xF5FA, /* LE == (Z || (N!=V)) */ + 0xFFFF, /* AL always */ + 0 /* NV */ +}; + +/* + * Check if a trapped instruction should have been executed or not. + */ +bool kvm_condition_valid32(const struct kvm_vcpu *vcpu) +{ + unsigned long cpsr; + u32 cpsr_cond; + int cond; + + /* Top two bits non-zero? Unconditional. */ + if (kvm_vcpu_get_hsr(vcpu) >> 30) + return true; + + /* Is condition field valid? */ + cond = kvm_vcpu_get_condition(vcpu); + if (cond == 0xE) + return true; + + cpsr = *vcpu_cpsr(vcpu); + + if (cond < 0) { + /* This can happen in Thumb mode: examine IT state. */ + unsigned long it; + + it = ((cpsr >> 8) & 0xFC) | ((cpsr >> 25) & 0x3); + + /* it == 0 => unconditional. */ + if (it == 0) + return true; + + /* The cond for this insn works out as the top 4 bits. */ + cond = (it >> 4); + } + + cpsr_cond = cpsr >> 28; + + if (!((cc_map[cond] >> cpsr_cond) & 1)) + return false; + + return true; +} + +/** + * adjust_itstate - adjust ITSTATE when emulating instructions in IT-block + * @vcpu: The VCPU pointer + * + * When exceptions occur while instructions are executed in Thumb IF-THEN + * blocks, the ITSTATE field of the CPSR is not advanced (updated), so we have + * to do this little bit of work manually. The fields map like this: + * + * IT[7:0] -> CPSR[26:25],CPSR[15:10] + */ +static void kvm_adjust_itstate(struct kvm_vcpu *vcpu) +{ + unsigned long itbits, cond; + unsigned long cpsr = *vcpu_cpsr(vcpu); + bool is_arm = !(cpsr & COMPAT_PSR_T_BIT); + + if (is_arm || !(cpsr & COMPAT_PSR_IT_MASK)) + return; + + cond = (cpsr & 0xe000) >> 13; + itbits = (cpsr & 0x1c00) >> (10 - 2); + itbits |= (cpsr & (0x3 << 25)) >> 25; + + /* Perform ITAdvance (see page A2-52 in ARM DDI 0406C) */ + if ((itbits & 0x7) == 0) + itbits = cond = 0; + else + itbits = (itbits << 1) & 0x1f; + + cpsr &= ~COMPAT_PSR_IT_MASK; + cpsr |= cond << 13; + cpsr |= (itbits & 0x1c) << (10 - 2); + cpsr |= (itbits & 0x3) << 25; + *vcpu_cpsr(vcpu) = cpsr; +} + +/** + * kvm_skip_instr - skip a trapped instruction and proceed to the next + * @vcpu: The vcpu pointer + */ +void kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr) +{ + bool is_thumb; + + is_thumb = !!(*vcpu_cpsr(vcpu) & COMPAT_PSR_T_BIT); + if (is_thumb && !is_wide_instr) + *vcpu_pc(vcpu) += 2; + else + *vcpu_pc(vcpu) += 4; + kvm_adjust_itstate(vcpu); +}
--
2.1.4