From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: [PATCH v5 12/40] KVM: arm64: Factor out fault info population and gic workarounds Date: Tue, 27 Feb 2018 12:34:01 +0100 Message-ID: <20180227113429.637-13-cdall@kernel.org> References: <20180227113429.637-1-cdall@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Marc Zyngier , Yury Norov , Dave Martin , Shih-Wei Li To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Return-path: In-Reply-To: <20180227113429.637-1-cdall@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org From: Christoffer Dall The current world-switch function has functionality to detect a number of cases where we need to fixup some part of the exit condition and possibly run the guest again, before having restored the host state. This includes populating missing fault info, emulating GICv2 CPU interface accesses when mapped at unaligned addresses, and emulating the GICv3 CPU interface on systems that need it. As we are about to have an alternative switch function for VHE systems, but VHE systems still need the same early fixup logic, factor out this logic into a separate function that can be shared by both switch functions. No functional change. Reviewed-by: Marc Zyngier Reviewed-by: Andrew Jones Signed-off-by: Christoffer Dall --- arch/arm64/kvm/hyp/switch.c | 104 ++++++++++++++++++++++++-------------------- 1 file changed, 57 insertions(+), 47 deletions(-) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 35f3bbe17084..b055111df1a1 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -291,53 +291,27 @@ static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu) } } -int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) +/* + * 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 + * main run loop. + */ +static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) { - struct kvm_cpu_context *host_ctxt; - struct kvm_cpu_context *guest_ctxt; - bool fp_enabled; - u64 exit_code; - - vcpu = kern_hyp_va(vcpu); - - host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); - host_ctxt->__hyp_running_vcpu = vcpu; - guest_ctxt = &vcpu->arch.ctxt; - - __sysreg_save_host_state(host_ctxt); - - __activate_traps(vcpu); - __activate_vm(vcpu); - - __vgic_restore_state(vcpu); - __timer_enable_traps(vcpu); - - /* - * We must restore the 32-bit state before the sysregs, thanks - * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). - */ - __sysreg32_restore_state(vcpu); - __sysreg_restore_guest_state(guest_ctxt); - __debug_switch_to_guest(vcpu); - - /* Jump in the fire! */ -again: - exit_code = __guest_enter(vcpu, host_ctxt); - /* And we're baaack! */ - - if (ARM_EXCEPTION_CODE(exit_code) != ARM_EXCEPTION_IRQ) + if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ) vcpu->arch.fault.esr_el2 = read_sysreg_el2(esr); + /* * We're using the raw exception code in order to only process * the trap if no SError is pending. We will come back to the * same PC once the SError has been injected, and replay the * trapping instruction. */ - if (exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) - goto again; + if (*exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) + return true; if (static_branch_unlikely(&vgic_v2_cpuif_trap) && - exit_code == ARM_EXCEPTION_TRAP) { + *exit_code == ARM_EXCEPTION_TRAP) { bool valid; valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW && @@ -351,9 +325,9 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) if (ret == 1) { if (__skip_instr(vcpu)) - goto again; + return true; else - exit_code = ARM_EXCEPTION_TRAP; + *exit_code = ARM_EXCEPTION_TRAP; } if (ret == -1) { @@ -365,29 +339,65 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) */ if (!__skip_instr(vcpu)) *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS; - exit_code = ARM_EXCEPTION_EL1_SERROR; + *exit_code = ARM_EXCEPTION_EL1_SERROR; } - - /* 0 falls through to be handler out of EL2 */ } } if (static_branch_unlikely(&vgic_v3_cpuif_trap) && - exit_code == ARM_EXCEPTION_TRAP && + *exit_code == ARM_EXCEPTION_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) { if (__skip_instr(vcpu)) - goto again; + return true; else - exit_code = ARM_EXCEPTION_TRAP; + *exit_code = ARM_EXCEPTION_TRAP; } - - /* 0 falls through to be handled out of EL2 */ } + /* Return to the host kernel and handle the exit */ + return false; +} + +int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + bool fp_enabled; + u64 exit_code; + + vcpu = kern_hyp_va(vcpu); + + host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + host_ctxt->__hyp_running_vcpu = vcpu; + guest_ctxt = &vcpu->arch.ctxt; + + __sysreg_save_host_state(host_ctxt); + + __activate_traps(vcpu); + __activate_vm(vcpu); + + __vgic_restore_state(vcpu); + __timer_enable_traps(vcpu); + + /* + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + */ + __sysreg32_restore_state(vcpu); + __sysreg_restore_guest_state(guest_ctxt); + __debug_switch_to_guest(vcpu); + + do { + /* Jump in the fire! */ + exit_code = __guest_enter(vcpu, host_ctxt); + + /* And we're baaack! */ + } while (fixup_guest_exit(vcpu, &exit_code)); + if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) { u32 midr = read_cpuid_id(); -- 2.14.2 From mboxrd@z Thu Jan 1 00:00:00 1970 From: cdall@kernel.org (Christoffer Dall) Date: Tue, 27 Feb 2018 12:34:01 +0100 Subject: [PATCH v5 12/40] KVM: arm64: Factor out fault info population and gic workarounds In-Reply-To: <20180227113429.637-1-cdall@kernel.org> References: <20180227113429.637-1-cdall@kernel.org> Message-ID: <20180227113429.637-13-cdall@kernel.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Christoffer Dall The current world-switch function has functionality to detect a number of cases where we need to fixup some part of the exit condition and possibly run the guest again, before having restored the host state. This includes populating missing fault info, emulating GICv2 CPU interface accesses when mapped at unaligned addresses, and emulating the GICv3 CPU interface on systems that need it. As we are about to have an alternative switch function for VHE systems, but VHE systems still need the same early fixup logic, factor out this logic into a separate function that can be shared by both switch functions. No functional change. Reviewed-by: Marc Zyngier Reviewed-by: Andrew Jones Signed-off-by: Christoffer Dall --- arch/arm64/kvm/hyp/switch.c | 104 ++++++++++++++++++++++++-------------------- 1 file changed, 57 insertions(+), 47 deletions(-) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 35f3bbe17084..b055111df1a1 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -291,53 +291,27 @@ static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu) } } -int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) +/* + * 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 + * main run loop. + */ +static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) { - struct kvm_cpu_context *host_ctxt; - struct kvm_cpu_context *guest_ctxt; - bool fp_enabled; - u64 exit_code; - - vcpu = kern_hyp_va(vcpu); - - host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); - host_ctxt->__hyp_running_vcpu = vcpu; - guest_ctxt = &vcpu->arch.ctxt; - - __sysreg_save_host_state(host_ctxt); - - __activate_traps(vcpu); - __activate_vm(vcpu); - - __vgic_restore_state(vcpu); - __timer_enable_traps(vcpu); - - /* - * We must restore the 32-bit state before the sysregs, thanks - * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). - */ - __sysreg32_restore_state(vcpu); - __sysreg_restore_guest_state(guest_ctxt); - __debug_switch_to_guest(vcpu); - - /* Jump in the fire! */ -again: - exit_code = __guest_enter(vcpu, host_ctxt); - /* And we're baaack! */ - - if (ARM_EXCEPTION_CODE(exit_code) != ARM_EXCEPTION_IRQ) + if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ) vcpu->arch.fault.esr_el2 = read_sysreg_el2(esr); + /* * We're using the raw exception code in order to only process * the trap if no SError is pending. We will come back to the * same PC once the SError has been injected, and replay the * trapping instruction. */ - if (exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) - goto again; + if (*exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) + return true; if (static_branch_unlikely(&vgic_v2_cpuif_trap) && - exit_code == ARM_EXCEPTION_TRAP) { + *exit_code == ARM_EXCEPTION_TRAP) { bool valid; valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW && @@ -351,9 +325,9 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) if (ret == 1) { if (__skip_instr(vcpu)) - goto again; + return true; else - exit_code = ARM_EXCEPTION_TRAP; + *exit_code = ARM_EXCEPTION_TRAP; } if (ret == -1) { @@ -365,29 +339,65 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) */ if (!__skip_instr(vcpu)) *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS; - exit_code = ARM_EXCEPTION_EL1_SERROR; + *exit_code = ARM_EXCEPTION_EL1_SERROR; } - - /* 0 falls through to be handler out of EL2 */ } } if (static_branch_unlikely(&vgic_v3_cpuif_trap) && - exit_code == ARM_EXCEPTION_TRAP && + *exit_code == ARM_EXCEPTION_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) { if (__skip_instr(vcpu)) - goto again; + return true; else - exit_code = ARM_EXCEPTION_TRAP; + *exit_code = ARM_EXCEPTION_TRAP; } - - /* 0 falls through to be handled out of EL2 */ } + /* Return to the host kernel and handle the exit */ + return false; +} + +int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + bool fp_enabled; + u64 exit_code; + + vcpu = kern_hyp_va(vcpu); + + host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + host_ctxt->__hyp_running_vcpu = vcpu; + guest_ctxt = &vcpu->arch.ctxt; + + __sysreg_save_host_state(host_ctxt); + + __activate_traps(vcpu); + __activate_vm(vcpu); + + __vgic_restore_state(vcpu); + __timer_enable_traps(vcpu); + + /* + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + */ + __sysreg32_restore_state(vcpu); + __sysreg_restore_guest_state(guest_ctxt); + __debug_switch_to_guest(vcpu); + + do { + /* Jump in the fire! */ + exit_code = __guest_enter(vcpu, host_ctxt); + + /* And we're baaack! */ + } while (fixup_guest_exit(vcpu, &exit_code)); + if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) { u32 midr = read_cpuid_id(); -- 2.14.2