diff options
author | Marc Zyngier <maz@kernel.org> | 2021-10-10 17:56:28 +0300 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2021-10-11 16:57:28 +0300 |
commit | 8fb2046180a0ad347f2e5bcae760dca67e65aa73 (patch) | |
tree | 140bf46595c4b47e5a5bc295e68fb587c1e2f71a /arch/arm64/kvm/hyp/include | |
parent | cc1e6fdfa92b82902883b70dafa729d3bd427b80 (diff) | |
download | linux-8fb2046180a0ad347f2e5bcae760dca67e65aa73.tar.xz |
KVM: arm64: Move early handlers to per-EC handlers
Simplify the early exception handling by slicing the gigantic decoding
tree into a more manageable set of functions, similar to what we have
in handle_exit.c.
This will also make the structure reusable for pKVM's own early exit
handling.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20211010145636.1950948-4-tabba@google.com
Diffstat (limited to 'arch/arm64/kvm/hyp/include')
-rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/switch.h | 160 |
1 files changed, 92 insertions, 68 deletions
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 54abc8298ec3..1e4177322be7 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -136,16 +136,7 @@ static inline void ___deactivate_traps(struct kvm_vcpu *vcpu) static inline bool __populate_fault_info(struct kvm_vcpu *vcpu) { - u8 ec; - u64 esr; - - esr = vcpu->arch.fault.esr_el2; - ec = ESR_ELx_EC(esr); - - if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW) - return true; - - return __get_fault_info(esr, &vcpu->arch.fault); + return __get_fault_info(vcpu->arch.fault.esr_el2, &vcpu->arch.fault); } static inline void __hyp_sve_save_host(struct kvm_vcpu *vcpu) @@ -166,8 +157,13 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu) write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR); } -/* Check for an FPSIMD/SVE trap and handle as appropriate */ -static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) +/* + * We trap the first access to the FP/SIMD to save the host context and + * restore the guest context lazily. + * If FP/SIMD is not implemented, handle the trap and inject an undefined + * instruction exception to the guest. Similarly for trapped SVE accesses. + */ +static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) { bool sve_guest, sve_host; u8 esr_ec; @@ -185,9 +181,6 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) } esr_ec = kvm_vcpu_trap_get_class(vcpu); - if (esr_ec != ESR_ELx_EC_FP_ASIMD && - esr_ec != ESR_ELx_EC_SVE) - return false; /* Don't handle SVE traps for non-SVE vcpus here: */ if (!sve_guest && esr_ec != ESR_ELx_EC_FP_ASIMD) @@ -325,7 +318,7 @@ static inline bool esr_is_ptrauth_trap(u32 esr) DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); -static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu) +static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code) { struct kvm_cpu_context *ctxt; u64 val; @@ -350,6 +343,87 @@ static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu) return true; } +static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) && + handle_tx2_tvm(vcpu)) + return true; + + if (static_branch_unlikely(&vgic_v3_cpuif_trap) && + __vgic_v3_perform_cpuif_access(vcpu) == 1) + return true; + + return false; +} + +static bool kvm_hyp_handle_cp15_32(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + if (static_branch_unlikely(&vgic_v3_cpuif_trap) && + __vgic_v3_perform_cpuif_access(vcpu) == 1) + return true; + + return false; +} + +static bool kvm_hyp_handle_iabt_low(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + if (!__populate_fault_info(vcpu)) + return true; + + return false; +} + +static bool kvm_hyp_handle_dabt_low(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + if (!__populate_fault_info(vcpu)) + return true; + + if (static_branch_unlikely(&vgic_v2_cpuif_trap)) { + bool valid; + + valid = kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT && + kvm_vcpu_dabt_isvalid(vcpu) && + !kvm_vcpu_abt_issea(vcpu) && + !kvm_vcpu_abt_iss1tw(vcpu); + + if (valid) { + int ret = __vgic_v2_perform_cpuif_access(vcpu); + + if (ret == 1) + return true; + + /* Promote an illegal access to an SError.*/ + if (ret == -1) + *exit_code = ARM_EXCEPTION_EL1_SERROR; + } + } + + return false; +} + +typedef bool (*exit_handler_fn)(struct kvm_vcpu *, u64 *); + +static const exit_handler_fn *kvm_get_exit_handler_array(void); + +/* + * Allow the hypervisor to handle the exit with an exit handler if it has one. + * + * Returns true if the hypervisor handled the exit, and control should go back + * to the guest, or false if it hasn't. + */ +static inline bool kvm_hyp_handle_exit(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + const exit_handler_fn *handlers = kvm_get_exit_handler_array(); + exit_handler_fn fn; + + fn = handlers[kvm_vcpu_trap_get_class(vcpu)]; + + if (fn) + return fn(vcpu, exit_code); + + return false; +} + /* * Return true when we were able to fixup the guest exit and should return to * the guest, false when we should restore the host state and return to the @@ -384,59 +458,9 @@ static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) if (*exit_code != ARM_EXCEPTION_TRAP) goto exit; - if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) && - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 && - handle_tx2_tvm(vcpu)) + /* Check if there's an exit handler and allow it to handle the exit. */ + if (kvm_hyp_handle_exit(vcpu, exit_code)) goto guest; - - /* - * We trap the first access to the FP/SIMD to save the host context - * and restore the guest context lazily. - * If FP/SIMD is not implemented, handle the trap and inject an - * undefined instruction exception to the guest. - * Similarly for trapped SVE accesses. - */ - if (__hyp_handle_fpsimd(vcpu)) - goto guest; - - if (__hyp_handle_ptrauth(vcpu)) - goto guest; - - if (!__populate_fault_info(vcpu)) - goto guest; - - if (static_branch_unlikely(&vgic_v2_cpuif_trap)) { - bool valid; - - valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW && - kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT && - kvm_vcpu_dabt_isvalid(vcpu) && - !kvm_vcpu_abt_issea(vcpu) && - !kvm_vcpu_abt_iss1tw(vcpu); - - if (valid) { - int ret = __vgic_v2_perform_cpuif_access(vcpu); - - if (ret == 1) - goto guest; - - /* Promote an illegal access to an SError.*/ - if (ret == -1) - *exit_code = ARM_EXCEPTION_EL1_SERROR; - - goto exit; - } - } - - if (static_branch_unlikely(&vgic_v3_cpuif_trap) && - (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 || - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) { - int ret = __vgic_v3_perform_cpuif_access(vcpu); - - if (ret == 1) - goto guest; - } - exit: /* Return to the host kernel and handle the exit */ return false; |