From 623e1528d4090bd1abaf93ec46f047dee9a6fb32 Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 22 May 2019 18:47:05 +0100 Subject: KVM: arm/arm64: Move cc/it checks under hyp's Makefile to avoid instrumentation 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 Signed-off-by: Marc Zyngier --- virt/kvm/arm/aarch32.c | 121 ------------------------------------------------- 1 file changed, 121 deletions(-) (limited to 'virt/kvm/arm/aarch32.c') 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 #include -/* - * 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. */ -- cgit v1.2.3