Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751501AbdFFXQW (ORCPT ); Tue, 6 Jun 2017 19:16:22 -0400 Received: from mail-ot0-f172.google.com ([74.125.82.172]:35534 "EHLO mail-ot0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751419AbdFFXQU (ORCPT ); Tue, 6 Jun 2017 19:16:20 -0400 MIME-Version: 1.0 In-Reply-To: References: <1483943091-1364-1-git-send-email-jintack@cs.columbia.edu> <1483943091-1364-12-git-send-email-jintack@cs.columbia.edu> From: Jintack Lim Date: Tue, 6 Jun 2017 19:16:17 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC 11/55] KVM: arm64: Emulate taking an exception to the guest hypervisor To: Bandan Das Cc: KVM General , Catalin Marinas , Will Deacon , kvmarm@lists.cs.columbia.edu, Shih-Wei Li , lorenzo.pieralisi@arm.com, linux@armlinux.org.uk, arm-mail-list , Marc Zyngier , Andre Przywara , kevin.brodsky@arm.com, wcohen@redhat.com, anna-maria@linutronix.de, geoff@infradead.org, lkml - Kernel Mailing List , Paolo Bonzini Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7780 Lines: 212 On Tue, Jun 6, 2017 at 6:07 PM, Bandan Das wrote: > Hi Jintack, > > Jintack Lim writes: > >> Hi Bandan, >> >> On Tue, Jun 6, 2017 at 4:21 PM, Bandan Das wrote: >>> Jintack Lim writes: >>> >>>> Emulate taking an exception to the guest hypervisor running in the >>>> virtual EL2 as described in ARM ARM AArch64.TakeException(). >>> >>> ARM newbie here, I keep thinking of ARM ARM as a typo ;) >> >> ARM ARM means ARM Architecture Reference Manual :) >> >>> ... >>>> +static inline int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2) >>>> +{ >>>> + kvm_err("Unexpected call to %s for the non-nesting configuration\n", >>>> + __func__); >>>> + return -EINVAL; >>>> +} >>>> + >>>> +static inline int kvm_inject_nested_irq(struct kvm_vcpu *vcpu) >>>> +{ >>>> + kvm_err("Unexpected call to %s for the non-nesting configuration\n", >>>> + __func__); >>>> + return -EINVAL; >>>> +} >>>> + >>> >>> I see these function stubs for aarch32 in the patches. I don't see how they >>> can actually be called though. Is this because eventually, there will be >>> a virtual el2 mode for aarch32 ? >> >> Current RFC doesn't support nested virtualization on 32bit arm >> architecture and those functions will be never called. Those functions >> are there for the compilation. > > Do you mean that compilation will fail ? Compilation on 32bit arm architecture will fail without them. > It seems these functions are > defined separately in 32/64 bit specific header files. Or is it that > 64 bit compilation also depends on the 32 bit header file ? It's only for 32bit architecture. For example, kvm_inject_nested_irq() is called in virt/kvm/arm/vgic/vgic.c which is shared between 32 and 64 bit. > > Bandan > >> Thanks, >> Jintack >> >>> >>> Bandan >>> >>>> static inline void kvm_arm_setup_shadow_state(struct kvm_vcpu *vcpu) { }; >>>> static inline void kvm_arm_restore_shadow_state(struct kvm_vcpu *vcpu) { }; >>>> static inline void kvm_arm_init_cpu_context(kvm_cpu_context_t *cpu_ctxt) { }; >>>> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h >>>> index 8892c82..0987ee4 100644 >>>> --- a/arch/arm64/include/asm/kvm_emulate.h >>>> +++ b/arch/arm64/include/asm/kvm_emulate.h >>>> @@ -42,6 +42,25 @@ >>>> void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr); >>>> void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); >>>> >>>> +#ifdef CONFIG_KVM_ARM_NESTED_HYP >>>> +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2); >>>> +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu); >>>> +#else >>>> +static inline int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2) >>>> +{ >>>> + kvm_err("Unexpected call to %s for the non-nesting configuration\n", >>>> + __func__); >>>> + return -EINVAL; >>>> +} >>>> + >>>> +static inline int kvm_inject_nested_irq(struct kvm_vcpu *vcpu) >>>> +{ >>>> + kvm_err("Unexpected call to %s for the non-nesting configuration\n", >>>> + __func__); >>>> + return -EINVAL; >>>> +} >>>> +#endif >>>> + >>>> void kvm_arm_setup_shadow_state(struct kvm_vcpu *vcpu); >>>> void kvm_arm_restore_shadow_state(struct kvm_vcpu *vcpu); >>>> void kvm_arm_init_cpu_context(kvm_cpu_context_t *cpu_ctxt); >>>> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile >>>> index 7811d27..b342bdd 100644 >>>> --- a/arch/arm64/kvm/Makefile >>>> +++ b/arch/arm64/kvm/Makefile >>>> @@ -34,3 +34,5 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-its.o >>>> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/irqchip.o >>>> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o >>>> kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o >>>> + >>>> +kvm-$(CONFIG_KVM_ARM_NESTED_HYP) += emulate-nested.o >>>> diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c >>>> new file mode 100644 >>>> index 0000000..59d147f >>>> --- /dev/null >>>> +++ b/arch/arm64/kvm/emulate-nested.c >>>> @@ -0,0 +1,66 @@ >>>> +/* >>>> + * Copyright (C) 2016 - Columbia University >>>> + * Author: Jintack Lim >>>> + * >>>> + * 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 . >>>> + */ >>>> + >>>> +#include >>>> +#include >>>> + >>>> +#include >>>> + >>>> +#include "trace.h" >>>> + >>>> +#define EL2_EXCEPT_SYNC_OFFSET 0x400 >>>> +#define EL2_EXCEPT_ASYNC_OFFSET 0x480 >>>> + >>>> + >>>> +/* >>>> + * Emulate taking an exception. See ARM ARM J8.1.2 AArch64.TakeException() >>>> + */ >>>> +static int kvm_inject_nested(struct kvm_vcpu *vcpu, u64 esr_el2, >>>> + int exception_offset) >>>> +{ >>>> + int ret = 1; >>>> + kvm_cpu_context_t *ctxt = &vcpu->arch.ctxt; >>>> + >>>> + /* We don't inject an exception recursively to virtual EL2 */ >>>> + if (vcpu_mode_el2(vcpu)) >>>> + BUG(); >>>> + >>>> + ctxt->el2_regs[SPSR_EL2] = *vcpu_cpsr(vcpu); >>>> + ctxt->el2_regs[ELR_EL2] = *vcpu_pc(vcpu); >>>> + ctxt->el2_regs[ESR_EL2] = esr_el2; >>>> + >>>> + /* On an exception, PSTATE.SP = 1 */ >>>> + *vcpu_cpsr(vcpu) = PSR_MODE_EL2h; >>>> + *vcpu_cpsr(vcpu) |= (PSR_A_BIT | PSR_F_BIT | PSR_I_BIT | PSR_D_BIT); >>>> + *vcpu_pc(vcpu) = ctxt->el2_regs[VBAR_EL2] + exception_offset; >>>> + >>>> + trace_kvm_inject_nested_exception(vcpu, esr_el2, *vcpu_pc(vcpu)); >>>> + >>>> + return ret; >>>> +} >>>> + >>>> +int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2) >>>> +{ >>>> + return kvm_inject_nested(vcpu, esr_el2, EL2_EXCEPT_SYNC_OFFSET); >>>> +} >>>> + >>>> +int kvm_inject_nested_irq(struct kvm_vcpu *vcpu) >>>> +{ >>>> + u64 esr_el2 = kvm_vcpu_get_hsr(vcpu); >>>> + /* We supports only IRQ and FIQ, so the esr_el2 is not updated. */ >>>> + return kvm_inject_nested(vcpu, esr_el2, EL2_EXCEPT_ASYNC_OFFSET); >>>> +} >>>> diff --git a/arch/arm64/kvm/trace.h b/arch/arm64/kvm/trace.h >>>> index 7fb0008..7c86cfb 100644 >>>> --- a/arch/arm64/kvm/trace.h >>>> +++ b/arch/arm64/kvm/trace.h >>>> @@ -167,6 +167,26 @@ >>>> ); >>>> >>>> >>>> +TRACE_EVENT(kvm_inject_nested_exception, >>>> + TP_PROTO(struct kvm_vcpu *vcpu, unsigned long esr_el2, >>>> + unsigned long pc), >>>> + TP_ARGS(vcpu, esr_el2, pc), >>>> + >>>> + TP_STRUCT__entry( >>>> + __field(struct kvm_vcpu *, vcpu) >>>> + __field(unsigned long, esr_el2) >>>> + __field(unsigned long, pc) >>>> + ), >>>> + >>>> + TP_fast_assign( >>>> + __entry->vcpu = vcpu; >>>> + __entry->esr_el2 = esr_el2; >>>> + __entry->pc = pc; >>>> + ), >>>> + >>>> + TP_printk("vcpu: %p, inject exception to vEL2: ESR_EL2 0x%lx, vector: 0x%016lx", >>>> + __entry->vcpu, __entry->esr_el2, __entry->pc) >>>> +); >>>> #endif /* _TRACE_ARM64_KVM_H */ >>>> >>>> #undef TRACE_INCLUDE_PATH >>> _______________________________________________ >>> kvmarm mailing list >>> kvmarm@lists.cs.columbia.edu >>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm