Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751593AbdFFUjB (ORCPT ); Tue, 6 Jun 2017 16:39:01 -0400 Received: from mail-ot0-f174.google.com ([74.125.82.174]:34334 "EHLO mail-ot0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426AbdFFUi6 (ORCPT ); Tue, 6 Jun 2017 16:38:58 -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 16:38:56 -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 , Jintack Lim 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: 6823 Lines: 192 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. 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