From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F43AC282CE for ; Mon, 8 Apr 2019 04:39:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDEEB20880 for ; Mon, 8 Apr 2019 04:39:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726212AbfDHEjM (ORCPT ); Mon, 8 Apr 2019 00:39:12 -0400 Received: from foss.arm.com ([217.140.101.70]:40956 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbfDHEjL (ORCPT ); Mon, 8 Apr 2019 00:39:11 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D0A9A15BF; Sun, 7 Apr 2019 21:39:10 -0700 (PDT) Received: from [10.162.0.144] (a075553-lin.blr.arm.com [10.162.0.144]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D459E3F718; Sun, 7 Apr 2019 21:39:07 -0700 (PDT) Subject: Re: [PATCH v8 5/9] KVM: arm/arm64: preserve host MDCR_EL2 value To: Dave Martin Cc: linux-arm-kernel@lists.infradead.org, Marc Zyngier , Catalin Marinas , Will Deacon , Kristina Martsenko , kvmarm@lists.cs.columbia.edu, Ramana Radhakrishnan , linux-kernel@vger.kernel.org References: <1554172037-4516-1-git-send-email-amit.kachhap@arm.com> <1554172037-4516-6-git-send-email-amit.kachhap@arm.com> <20190405110237.GS3567@e103592.cambridge.arm.com> From: Amit Daniel Kachhap Message-ID: <98786a02-8faf-4858-92c2-01eb5580ab3d@arm.com> Date: Mon, 8 Apr 2019 10:09:05 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190405110237.GS3567@e103592.cambridge.arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 4/5/19 4:32 PM, Dave Martin wrote: > On Tue, Apr 02, 2019 at 07:57:13AM +0530, Amit Daniel Kachhap wrote: >> Save host MDCR_EL2 value during kvm HYP initialisation and restore >> after every switch from host to guest. There should not be any >> change in functionality due to this. >> >> The value of mdcr_el2 is now stored in struct kvm_cpu_context as >> both host and guest can now use this field in a common way. >> >> Signed-off-by: Amit Daniel Kachhap >> Acked-by: Mark Rutland >> Cc: Marc Zyngier >> Cc: Mark Rutland >> Cc: Christoffer Dall >> Cc: kvmarm@lists.cs.columbia.edu >> --- >> >> Changes since v7: >> * Removed unused function __kvm_get_mdcr_el2 [Kristina]. >> >> arch/arm/include/asm/kvm_host.h | 1 - >> arch/arm64/include/asm/kvm_asm.h | 2 -- >> arch/arm64/include/asm/kvm_host.h | 6 ++---- >> arch/arm64/include/asm/kvm_hyp.h | 2 +- >> arch/arm64/kvm/debug.c | 28 ++++++---------------------- >> arch/arm64/kvm/hyp/debug-sr.c | 5 ----- >> arch/arm64/kvm/hyp/switch.c | 18 +++++------------- >> arch/arm64/kvm/hyp/sysreg-sr.c | 8 +++++++- >> virt/kvm/arm/arm.c | 1 - >> 9 files changed, 21 insertions(+), 50 deletions(-) >> >> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h >> index 6d0aac4..a928565 100644 >> --- a/arch/arm/include/asm/kvm_host.h >> +++ b/arch/arm/include/asm/kvm_host.h >> @@ -343,7 +343,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} >> static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} >> static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} >> >> -static inline void kvm_arm_init_debug(void) {} >> static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} >> static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} >> static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} >> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h >> index a68205c..a15ba55 100644 >> --- a/arch/arm64/include/asm/kvm_asm.h >> +++ b/arch/arm64/include/asm/kvm_asm.h >> @@ -78,8 +78,6 @@ extern u64 __vgic_v3_read_vmcr(void); >> extern void __vgic_v3_write_vmcr(u32 vmcr); >> extern void __vgic_v3_init_lrs(void); >> >> -extern u32 __kvm_get_mdcr_el2(void); >> - >> extern void __kvm_populate_host_regs(void); >> >> /* >> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h >> index 3b09fd0..e3ccd7b 100644 >> --- a/arch/arm64/include/asm/kvm_host.h >> +++ b/arch/arm64/include/asm/kvm_host.h >> @@ -211,6 +211,8 @@ struct kvm_cpu_context { >> >> /* HYP host/guest configuration */ >> u64 hcr_el2; >> + u32 mdcr_el2; >> + >> struct kvm_vcpu *__hyp_running_vcpu; >> }; >> >> @@ -226,9 +228,6 @@ struct vcpu_reset_state { >> struct kvm_vcpu_arch { >> struct kvm_cpu_context ctxt; >> >> - /* HYP configuration */ >> - u32 mdcr_el2; >> - >> /* Exception Information */ >> struct kvm_vcpu_fault_info fault; >> >> @@ -498,7 +497,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} >> static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} >> static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} >> >> -void kvm_arm_init_debug(void); >> void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); >> void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); >> void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu); >> diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h >> index 4da765f..7fcde8a 100644 >> --- a/arch/arm64/include/asm/kvm_hyp.h >> +++ b/arch/arm64/include/asm/kvm_hyp.h >> @@ -152,7 +152,7 @@ void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs); >> bool __fpsimd_enabled(void); >> >> void activate_traps_vhe_load(struct kvm_vcpu *vcpu); >> -void deactivate_traps_vhe_put(void); >> +void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu); >> >> u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt); >> void __noreturn __hyp_do_panic(unsigned long, ...); >> diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c >> index fd917d6..99dc0a4 100644 >> --- a/arch/arm64/kvm/debug.c >> +++ b/arch/arm64/kvm/debug.c >> @@ -32,8 +32,6 @@ >> DBG_MDSCR_KDE | \ >> DBG_MDSCR_MDE) >> >> -static DEFINE_PER_CPU(u32, mdcr_el2); >> - >> /** >> * save/restore_guest_debug_regs >> * >> @@ -65,21 +63,6 @@ static void restore_guest_debug_regs(struct kvm_vcpu *vcpu) >> } >> >> /** >> - * kvm_arm_init_debug - grab what we need for debug >> - * >> - * Currently the sole task of this function is to retrieve the initial >> - * value of mdcr_el2 so we can preserve MDCR_EL2.HPMN which has >> - * presumably been set-up by some knowledgeable bootcode. >> - * >> - * It is called once per-cpu during CPU hyp initialisation. >> - */ >> - >> -void kvm_arm_init_debug(void) >> -{ >> - __this_cpu_write(mdcr_el2, kvm_call_hyp_ret(__kvm_get_mdcr_el2)); >> -} >> - >> -/** >> * kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state >> */ >> >> @@ -111,6 +94,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) >> >> void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) >> { >> + kvm_cpu_context_t *host_cxt = this_cpu_ptr(&kvm_host_cpu_state); >> bool trap_debug = !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY); >> unsigned long mdscr; >> >> @@ -120,8 +104,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) >> * This also clears MDCR_EL2_E2PB_MASK to disable guest access >> * to the profiling buffer. >> */ >> - vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK; >> - vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM | >> + vcpu->arch.ctxt.mdcr_el2 = host_cxt->mdcr_el2 & MDCR_EL2_HPMN_MASK; >> + vcpu->arch.ctxt.mdcr_el2 |= (MDCR_EL2_TPM | >> MDCR_EL2_TPMS | >> MDCR_EL2_TPMCR | >> MDCR_EL2_TDRA | >> @@ -130,7 +114,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) >> /* Is Guest debugging in effect? */ >> if (vcpu->guest_debug) { >> /* Route all software debug exceptions to EL2 */ >> - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE; >> + vcpu->arch.ctxt.mdcr_el2 |= MDCR_EL2_TDE; >> >> /* Save guest debug state */ >> save_guest_debug_regs(vcpu); >> @@ -202,13 +186,13 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) >> >> /* Trap debug register access */ >> if (trap_debug) >> - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; >> + vcpu->arch.ctxt.mdcr_el2 |= MDCR_EL2_TDA; >> >> /* If KDE or MDE are set, perform a full save/restore cycle. */ >> if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE)) >> vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY; >> >> - trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2); >> + trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.ctxt.mdcr_el2); >> trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1)); >> } >> >> diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c >> index 5000976..f49a3f7 100644 >> --- a/arch/arm64/kvm/hyp/debug-sr.c >> +++ b/arch/arm64/kvm/hyp/debug-sr.c >> @@ -198,8 +198,3 @@ void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu) >> >> vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY; >> } >> - >> -u32 __hyp_text __kvm_get_mdcr_el2(void) >> -{ >> - return read_sysreg(mdcr_el2); >> -} >> diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c >> index f5cefa1..fe76e24 100644 >> --- a/arch/arm64/kvm/hyp/switch.c >> +++ b/arch/arm64/kvm/hyp/switch.c >> @@ -84,7 +84,7 @@ static void __hyp_text __activate_traps_common(struct kvm_vcpu *vcpu) >> */ >> write_sysreg(0, pmselr_el0); >> write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); >> - write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); >> + write_sysreg(vcpu->arch.ctxt.mdcr_el2, mdcr_el2); >> } >> >> static void __hyp_text __deactivate_traps_common(void) >> @@ -161,15 +161,11 @@ NOKPROBE_SYMBOL(deactivate_traps_vhe); >> >> static void __hyp_text __deactivate_traps_nvhe(struct kvm_cpu_context *host_ctxt) >> { >> - u64 mdcr_el2 = read_sysreg(mdcr_el2); >> struct kvm_cpu_context *hyp_host_ctxt = kern_hyp_va(host_ctxt); >> >> __deactivate_traps_common(); >> >> - mdcr_el2 &= MDCR_EL2_HPMN_MASK; >> - mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; >> - >> - write_sysreg(mdcr_el2, mdcr_el2); >> + write_sysreg(hyp_host_ctxt->mdcr_el2, mdcr_el2); >> write_sysreg(hyp_host_ctxt->hcr_el2, hcr_el2); >> write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); >> } >> @@ -199,15 +195,11 @@ void activate_traps_vhe_load(struct kvm_vcpu *vcpu) >> __activate_traps_common(vcpu); >> } >> >> -void deactivate_traps_vhe_put(void) >> +void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu) >> { >> - u64 mdcr_el2 = read_sysreg(mdcr_el2); >> - >> - mdcr_el2 &= MDCR_EL2_HPMN_MASK | >> - MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT | >> - MDCR_EL2_TPMS; >> + struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context; >> >> - write_sysreg(mdcr_el2, mdcr_el2); >> + write_sysreg(host_ctxt->mdcr_el2, mdcr_el2); >> >> __deactivate_traps_common(); >> } >> diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c >> index 277f82b..6afd309 100644 >> --- a/arch/arm64/kvm/hyp/sysreg-sr.c >> +++ b/arch/arm64/kvm/hyp/sysreg-sr.c >> @@ -298,7 +298,7 @@ void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) >> if (!has_vhe()) >> return; >> >> - deactivate_traps_vhe_put(); >> + deactivate_traps_vhe_put(vcpu); >> >> __sysreg_save_el1_state(guest_ctxt); >> __sysreg_save_user_state(guest_ctxt); >> @@ -333,4 +333,10 @@ void __hyp_text __kvm_populate_host_regs(void) >> >> host_ctxt = __hyp_this_cpu_ptr(kvm_host_cpu_state); >> host_ctxt->hcr_el2 = read_sysreg(hcr_el2); >> + /* >> + * Retrieve the initial value of mdcr_el2 so we can preserve >> + * MDCR_EL2.HPMN which has presumably been set-up by some >> + * knowledgeable bootcode. >> + */ >> + host_ctxt->mdcr_el2 = read_sysreg(mdcr_el2); >> } >> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c >> index e8c2ee6..58de0ca 100644 >> --- a/virt/kvm/arm/arm.c >> +++ b/virt/kvm/arm/arm.c >> @@ -1322,7 +1322,6 @@ static void cpu_hyp_reinit(void) >> else >> cpu_init_hyp_mode(NULL); >> >> - kvm_arm_init_debug(); >> cpu_init_host_ctxt(); >> >> if (vgic_present) > > Looks reasonable overall. > > I was wondering whether it would make sense to move some masking into > __kvm_populate_host_regs(), but probably not. > > Reviewed-by: Dave Martin Thanks for the review. Thanks, Amit D. > > Cheers > ---Dave > > >> -- >> 2.7.4 >> >> _______________________________________________ >> kvmarm mailing list >> kvmarm@lists.cs.columbia.edu >> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm