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Diffstat (limited to 'arch/arm64/kvm/inject_fault.c')
| -rw-r--r-- | arch/arm64/kvm/inject_fault.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c new file mode 100644 index 0000000000..0bd93a5f21 --- /dev/null +++ b/arch/arm64/kvm/inject_fault.c @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Fault injection for both 32 and 64bit 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_nested.h> +#include <asm/esr.h> + +static void pend_sync_exception(struct kvm_vcpu *vcpu) +{ + /* If not nesting, EL1 is the only possible exception target */ + if (likely(!vcpu_has_nv(vcpu))) { + kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC); + return; + } + + /* + * With NV, we need to pick between EL1 and EL2. Note that we + * never deal with a nesting exception here, hence never + * changing context, and the exception itself can be delayed + * until the next entry. + */ + switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) { + case PSR_MODE_EL2h: + case PSR_MODE_EL2t: + kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC); + break; + case PSR_MODE_EL1h: + case PSR_MODE_EL1t: + kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC); + break; + case PSR_MODE_EL0t: + if (vcpu_el2_tge_is_set(vcpu)) + kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC); + else + kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC); + break; + default: + BUG(); + } +} + +static bool match_target_el(struct kvm_vcpu *vcpu, unsigned long target) +{ + return (vcpu_get_flag(vcpu, EXCEPT_MASK) == target); +} + +static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr) +{ + unsigned long cpsr = *vcpu_cpsr(vcpu); + bool is_aarch32 = vcpu_mode_is_32bit(vcpu); + u64 esr = 0; + + pend_sync_exception(vcpu); + + /* + * Build an {i,d}abort, depending on the level and the + * instruction set. Report an external synchronous abort. + */ + if (kvm_vcpu_trap_il_is32bit(vcpu)) + esr |= ESR_ELx_IL; + + /* + * Here, the guest runs in AArch64 mode when in EL1. If we get + * an AArch32 fault, it means we managed to trap an EL0 fault. + */ + if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t) + esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT); + else + esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT); + + if (!is_iabt) + esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT; + + esr |= ESR_ELx_FSC_EXTABT; + + if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC))) { + vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + } else { + vcpu_write_sys_reg(vcpu, addr, FAR_EL2); + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); + } +} + +static void inject_undef64(struct kvm_vcpu *vcpu) +{ + u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); + + pend_sync_exception(vcpu); + + /* + * Build an unknown exception, depending on the instruction + * set. + */ + if (kvm_vcpu_trap_il_is32bit(vcpu)) + esr |= ESR_ELx_IL; + + if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC))) + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + else + vcpu_write_sys_reg(vcpu, esr, ESR_EL2); +} + +#define DFSR_FSC_EXTABT_LPAE 0x10 +#define DFSR_FSC_EXTABT_nLPAE 0x08 +#define DFSR_LPAE BIT(9) +#define TTBCR_EAE BIT(31) + +static void inject_undef32(struct kvm_vcpu *vcpu) +{ + kvm_pend_exception(vcpu, EXCEPT_AA32_UND); +} + +/* + * Modelled after TakeDataAbortException() and TakePrefetchAbortException + * pseudocode. + */ +static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr) +{ + u64 far; + u32 fsr; + + /* Give the guest an IMPLEMENTATION DEFINED exception */ + if (vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) { + fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE; + } else { + /* no need to shuffle FS[4] into DFSR[10] as its 0 */ + fsr = DFSR_FSC_EXTABT_nLPAE; + } + + far = vcpu_read_sys_reg(vcpu, FAR_EL1); + + if (is_pabt) { + kvm_pend_exception(vcpu, EXCEPT_AA32_IABT); + far &= GENMASK(31, 0); + far |= (u64)addr << 32; + vcpu_write_sys_reg(vcpu, fsr, IFSR32_EL2); + } else { /* !iabt */ + kvm_pend_exception(vcpu, EXCEPT_AA32_DABT); + far &= GENMASK(63, 32); + far |= addr; + vcpu_write_sys_reg(vcpu, fsr, ESR_EL1); + } + + vcpu_write_sys_reg(vcpu, far, FAR_EL1); +} + +/** + * kvm_inject_dabt - inject a data abort into the guest + * @vcpu: The VCPU to receive the data abort + * @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) +{ + if (vcpu_el1_is_32bit(vcpu)) + inject_abt32(vcpu, false, addr); + else + inject_abt64(vcpu, false, addr); +} + +/** + * kvm_inject_pabt - inject a prefetch abort into the guest + * @vcpu: The VCPU to receive the prefetch abort + * @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) +{ + if (vcpu_el1_is_32bit(vcpu)) + inject_abt32(vcpu, true, addr); + else + inject_abt64(vcpu, true, addr); +} + +void kvm_inject_size_fault(struct kvm_vcpu *vcpu) +{ + unsigned long addr, esr; + + addr = kvm_vcpu_get_fault_ipa(vcpu); + addr |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); + + if (kvm_vcpu_trap_is_iabt(vcpu)) + kvm_inject_pabt(vcpu, addr); + else + kvm_inject_dabt(vcpu, addr); + + /* + * If AArch64 or LPAE, set FSC to 0 to indicate an Address + * Size Fault at level 0, as if exceeding PARange. + * + * Non-LPAE guests will only get the external abort, as there + * is no way to describe the ASF. + */ + if (vcpu_el1_is_32bit(vcpu) && + !(vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE)) + return; + + esr = vcpu_read_sys_reg(vcpu, ESR_EL1); + esr &= ~GENMASK_ULL(5, 0); + vcpu_write_sys_reg(vcpu, esr, ESR_EL1); +} + +/** + * kvm_inject_undefined - inject an undefined instruction into the guest + * @vcpu: The vCPU in which to inject 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_undefined(struct kvm_vcpu *vcpu) +{ + if (vcpu_el1_is_32bit(vcpu)) + inject_undef32(vcpu); + else + inject_undef64(vcpu); +} + +void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 esr) +{ + vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK); + *vcpu_hcr(vcpu) |= HCR_VSE; +} + +/** + * 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. + * + * Systems with the RAS Extensions specify an imp-def ESR (ISV/IDS = 1) with + * the remaining ISS all-zeros so that this error is not interpreted as an + * uncategorized RAS error. Without the RAS Extensions we can't specify an ESR + * value, so the CPU generates an imp-def value. + */ +void kvm_inject_vabt(struct kvm_vcpu *vcpu) +{ + kvm_set_sei_esr(vcpu, ESR_ELx_ISV); +} |