[ Upstream commit 623e1528d4090bd1abaf93ec46f047dee9a6fb32 ]
KVM has helpers to handle the condition codes of trapped aarch32 instructions. These are marked __hyp_text and used from HYP, but they aren't built by the 'hyp' Makefile, which has all the runes to avoid ASAN and KCOV instrumentation.
Move this code to a new hyp/aarch32.c to avoid a hyp-panic when starting an aarch32 guest on a host built with the ASAN/KCOV debug options.
Fixes: 021234ef3752f ("KVM: arm64: Make kvm_condition_valid32() accessible from EL2") Fixes: 8cebe750c4d9a ("arm64: KVM: Make kvm_skip_instr32 available to HYP") Signed-off-by: James Morse james.morse@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/kvm/hyp/Makefile | 1 + arch/arm64/kvm/hyp/Makefile | 1 + virt/kvm/arm/aarch32.c | 121 -------------------------------- virt/kvm/arm/hyp/aarch32.c | 136 ++++++++++++++++++++++++++++++++++++ 4 files changed, 138 insertions(+), 121 deletions(-) create mode 100644 virt/kvm/arm/hyp/aarch32.c
diff --git a/arch/arm/kvm/hyp/Makefile b/arch/arm/kvm/hyp/Makefile index d2b5ec9c4b92..ba88b1eca93c 100644 --- a/arch/arm/kvm/hyp/Makefile +++ b/arch/arm/kvm/hyp/Makefile @@ -11,6 +11,7 @@ CFLAGS_ARMV7VE :=$(call cc-option, -march=armv7ve)
obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v3-sr.o obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/timer-sr.o +obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/aarch32.o
obj-$(CONFIG_KVM_ARM_HOST) += tlb.o obj-$(CONFIG_KVM_ARM_HOST) += cp15-sr.o diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index 82d1904328ad..ea710f674cb6 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -10,6 +10,7 @@ KVM=../../../../virt/kvm
obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v3-sr.o obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/timer-sr.o +obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/aarch32.o
obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-cpuif-proxy.o obj-$(CONFIG_KVM_ARM_HOST) += sysreg-sr.o diff --git a/virt/kvm/arm/aarch32.c b/virt/kvm/arm/aarch32.c index 5abbe9b3c652..6880236974b8 100644 --- a/virt/kvm/arm/aarch32.c +++ b/virt/kvm/arm/aarch32.c @@ -25,127 +25,6 @@ #include <asm/kvm_emulate.h> #include <asm/kvm_hyp.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 __hyp_text 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 __hyp_text kvm_adjust_itstate(struct kvm_vcpu *vcpu) -{ - unsigned long itbits, cond; - unsigned long cpsr = *vcpu_cpsr(vcpu); - bool is_arm = !(cpsr & PSR_AA32_T_BIT); - - if (is_arm || !(cpsr & PSR_AA32_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 &= ~PSR_AA32_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 __hyp_text kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr) -{ - bool is_thumb; - - is_thumb = !!(*vcpu_cpsr(vcpu) & PSR_AA32_T_BIT); - if (is_thumb && !is_wide_instr) - *vcpu_pc(vcpu) += 2; - else - *vcpu_pc(vcpu) += 4; - kvm_adjust_itstate(vcpu); -} - /* * Table taken from ARMv8 ARM DDI0487B-B, table G1-10. */ diff --git a/virt/kvm/arm/hyp/aarch32.c b/virt/kvm/arm/hyp/aarch32.c new file mode 100644 index 000000000000..d31f267961e7 --- /dev/null +++ b/virt/kvm/arm/hyp/aarch32.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Hyp portion of the (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 + */ + +#include <linux/kvm_host.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.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 __hyp_text 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 __hyp_text kvm_adjust_itstate(struct kvm_vcpu *vcpu) +{ + unsigned long itbits, cond; + unsigned long cpsr = *vcpu_cpsr(vcpu); + bool is_arm = !(cpsr & PSR_AA32_T_BIT); + + if (is_arm || !(cpsr & PSR_AA32_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 &= ~PSR_AA32_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 __hyp_text kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr) +{ + bool is_thumb; + + is_thumb = !!(*vcpu_cpsr(vcpu) & PSR_AA32_T_BIT); + if (is_thumb && !is_wide_instr) + *vcpu_pc(vcpu) += 2; + else + *vcpu_pc(vcpu) += 4; + kvm_adjust_itstate(vcpu); +}