diff options
Diffstat (limited to 'arch/arm64/kvm/inject_fault.c')
| -rw-r--r-- | arch/arm64/kvm/inject_fault.c | 364 |
1 files changed, 269 insertions, 95 deletions
diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index a55e91dfcf8f..dfcd66c65517 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Fault injection for both 32 and 64bit guests. * @@ -7,73 +8,134 @@ * 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> +#include <asm/kvm_nested.h> #include <asm/esr.h> -#define PSTATE_FAULT_BITS_64 (PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | \ - PSR_I_BIT | PSR_D_BIT) - -#define CURRENT_EL_SP_EL0_VECTOR 0x0 -#define CURRENT_EL_SP_ELx_VECTOR 0x200 -#define LOWER_EL_AArch64_VECTOR 0x400 -#define LOWER_EL_AArch32_VECTOR 0x600 - -enum exception_type { - except_type_sync = 0, - except_type_irq = 0x80, - except_type_fiq = 0x100, - except_type_serror = 0x180, -}; - -static u64 get_except_vector(struct kvm_vcpu *vcpu, enum exception_type type) +static unsigned int exception_target_el(struct kvm_vcpu *vcpu) { - u64 exc_offset; + /* If not nesting, EL1 is the only possible exception target */ + if (likely(!vcpu_has_nv(vcpu))) + return PSR_MODE_EL1h; - switch (*vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT)) { - case PSR_MODE_EL1t: - exc_offset = CURRENT_EL_SP_EL0_VECTOR; - break; + /* + * 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: + return PSR_MODE_EL2h; case PSR_MODE_EL1h: - exc_offset = CURRENT_EL_SP_ELx_VECTOR; - break; + case PSR_MODE_EL1t: + return PSR_MODE_EL1h; case PSR_MODE_EL0t: - exc_offset = LOWER_EL_AArch64_VECTOR; - break; + return vcpu_el2_tge_is_set(vcpu) ? PSR_MODE_EL2h : PSR_MODE_EL1h; default: - exc_offset = LOWER_EL_AArch32_VECTOR; + BUG(); } +} + +static enum vcpu_sysreg exception_esr_elx(struct kvm_vcpu *vcpu) +{ + if (exception_target_el(vcpu) == PSR_MODE_EL2h) + return ESR_EL2; + + return ESR_EL1; +} + +static enum vcpu_sysreg exception_far_elx(struct kvm_vcpu *vcpu) +{ + if (exception_target_el(vcpu) == PSR_MODE_EL2h) + return FAR_EL2; + + return FAR_EL1; +} + +static void pend_sync_exception(struct kvm_vcpu *vcpu) +{ + if (exception_target_el(vcpu) == PSR_MODE_EL1h) + kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC); + else + kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC); +} + +static void pend_serror_exception(struct kvm_vcpu *vcpu) +{ + if (exception_target_el(vcpu) == PSR_MODE_EL1h) + kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SERR); + else + kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SERR); +} + +static bool __effective_sctlr2_bit(struct kvm_vcpu *vcpu, unsigned int idx) +{ + u64 sctlr2; + + if (!kvm_has_sctlr2(vcpu->kvm)) + return false; - return vcpu_read_sys_reg(vcpu, VBAR_EL1) + exc_offset + type; + if (is_nested_ctxt(vcpu) && + !(__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_SCTLR2En)) + return false; + + if (exception_target_el(vcpu) == PSR_MODE_EL1h) + sctlr2 = vcpu_read_sys_reg(vcpu, SCTLR2_EL1); + else + sctlr2 = vcpu_read_sys_reg(vcpu, SCTLR2_EL2); + + return sctlr2 & BIT(idx); +} + +static bool effective_sctlr2_ease(struct kvm_vcpu *vcpu) +{ + return __effective_sctlr2_bit(vcpu, SCTLR2_EL1_EASE_SHIFT); +} + +static bool effective_sctlr2_nmea(struct kvm_vcpu *vcpu) +{ + return __effective_sctlr2_bit(vcpu, SCTLR2_EL1_NMEA_SHIFT); } 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); - u32 esr = 0; + u64 esr = 0, fsc; + int level; + + /* + * If injecting an abort from a failed S1PTW, rewalk the S1 PTs to + * find the failing level. If we can't find it, assume the error was + * transient and restart without changing the state. + */ + if (kvm_vcpu_abt_iss1tw(vcpu)) { + u64 hpfar = kvm_vcpu_get_fault_ipa(vcpu); + int ret; - vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu)); - *vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync); + if (hpfar == INVALID_GPA) + return; - *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; - vcpu_write_spsr(vcpu, cpsr); + ret = __kvm_find_s1_desc_level(vcpu, addr, hpfar, &level); + if (ret) + return; - vcpu_write_sys_reg(vcpu, addr, FAR_EL1); + WARN_ON_ONCE(level < -1 || level > 3); + fsc = ESR_ELx_FSC_SEA_TTW(level); + } else { + fsc = ESR_ELx_FSC_EXTABT; + } + + /* This delight is brought to you by FEAT_DoubleFault2. */ + if (effective_sctlr2_ease(vcpu)) + pend_serror_exception(vcpu); + else + pend_sync_exception(vcpu); /* * Build an {i,d}abort, depending on the level and the @@ -94,19 +156,17 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr if (!is_iabt) esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT; - vcpu_write_sys_reg(vcpu, esr | ESR_ELx_FSC_EXTABT, ESR_EL1); + esr |= fsc; + + vcpu_write_sys_reg(vcpu, addr, exception_far_elx(vcpu)); + vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu)); } static void inject_undef64(struct kvm_vcpu *vcpu) { - unsigned long cpsr = *vcpu_cpsr(vcpu); - u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); + u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); - vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu)); - *vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync); - - *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; - vcpu_write_spsr(vcpu, cpsr); + pend_sync_exception(vcpu); /* * Build an unknown exception, depending on the instruction @@ -115,43 +175,112 @@ static void inject_undef64(struct kvm_vcpu *vcpu) if (kvm_vcpu_trap_il_is32bit(vcpu)) esr |= ESR_ELx_IL; - vcpu_write_sys_reg(vcpu, esr, ESR_EL1); + vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu)); } -/** - * 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) +#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) { - if (vcpu_el1_is_32bit(vcpu)) - kvm_inject_dabt32(vcpu, addr); - else - inject_abt64(vcpu, false, addr); + kvm_pend_exception(vcpu, EXCEPT_AA32_UND); } -/** - * 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. +/* + * Modelled after TakeDataAbortException() and TakePrefetchAbortException + * pseudocode. */ -void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr) +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 it's 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); +} + +static void __kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr) { if (vcpu_el1_is_32bit(vcpu)) - kvm_inject_pabt32(vcpu, addr); + inject_abt32(vcpu, iabt, addr); else - inject_abt64(vcpu, true, addr); + inject_abt64(vcpu, iabt, addr); +} + +static bool kvm_sea_target_is_el2(struct kvm_vcpu *vcpu) +{ + if (__vcpu_sys_reg(vcpu, HCR_EL2) & (HCR_TGE | HCR_TEA)) + return true; + + if (!vcpu_mode_priv(vcpu)) + return false; + + return (*vcpu_cpsr(vcpu) & PSR_A_BIT) && + (__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TMEA); +} + +int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr) +{ + lockdep_assert_held(&vcpu->mutex); + + if (is_nested_ctxt(vcpu) && kvm_sea_target_is_el2(vcpu)) + return kvm_inject_nested_sea(vcpu, iabt, addr); + + __kvm_inject_sea(vcpu, iabt, addr); + return 1; +} + +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); + + __kvm_inject_sea(vcpu, kvm_vcpu_trap_is_iabt(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, exception_esr_elx(vcpu)); + esr &= ~GENMASK_ULL(5, 0); + vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu)); } /** * 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. @@ -159,30 +288,75 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr) void kvm_inject_undefined(struct kvm_vcpu *vcpu) { if (vcpu_el1_is_32bit(vcpu)) - kvm_inject_undef32(vcpu); + inject_undef32(vcpu); else inject_undef64(vcpu); } -void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 esr) +static bool serror_is_masked(struct kvm_vcpu *vcpu) { - vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK); - *vcpu_hcr(vcpu) |= HCR_VSE; + return (*vcpu_cpsr(vcpu) & PSR_A_BIT) && !effective_sctlr2_nmea(vcpu); } -/** - * 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) +static bool kvm_serror_target_is_el2(struct kvm_vcpu *vcpu) +{ + if (is_hyp_ctxt(vcpu) || vcpu_el2_amo_is_set(vcpu)) + return true; + + if (!(__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TMEA)) + return false; + + /* + * In another example where FEAT_DoubleFault2 is entirely backwards, + * "masked" as it relates to the routing effects of HCRX_EL2.TMEA + * doesn't consider SCTLR2_EL1.NMEA. That is to say, even if EL1 asked + * for non-maskable SErrors, the EL2 bit takes priority if A is set. + */ + if (vcpu_mode_priv(vcpu)) + return *vcpu_cpsr(vcpu) & PSR_A_BIT; + + /* + * Otherwise SErrors are considered unmasked when taken from EL0 and + * NMEA is set. + */ + return serror_is_masked(vcpu); +} + +static bool kvm_serror_undeliverable_at_el2(struct kvm_vcpu *vcpu) +{ + return !(vcpu_el2_tge_is_set(vcpu) || vcpu_el2_amo_is_set(vcpu)); +} + +int kvm_inject_serror_esr(struct kvm_vcpu *vcpu, u64 esr) { - kvm_set_sei_esr(vcpu, ESR_ELx_ISV); + lockdep_assert_held(&vcpu->mutex); + + if (is_nested_ctxt(vcpu) && kvm_serror_target_is_el2(vcpu)) + return kvm_inject_nested_serror(vcpu, esr); + + if (vcpu_is_el2(vcpu) && kvm_serror_undeliverable_at_el2(vcpu)) { + vcpu_set_vsesr(vcpu, esr); + vcpu_set_flag(vcpu, NESTED_SERROR_PENDING); + return 1; + } + + /* + * Emulate the exception entry if SErrors are unmasked. This is useful if + * the vCPU is in a nested context w/ vSErrors enabled then we've already + * delegated he hardware vSError context (i.e. HCR_EL2.VSE, VSESR_EL2, + * VDISR_EL2) to the guest hypervisor. + * + * As we're emulating the SError injection we need to explicitly populate + * ESR_ELx.EC because hardware will not do it on our behalf. + */ + if (!serror_is_masked(vcpu)) { + pend_serror_exception(vcpu); + esr |= FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_SERROR); + vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu)); + return 1; + } + + vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK); + *vcpu_hcr(vcpu) |= HCR_VSE; + return 1; } |