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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 7459CC43460 for ; Mon, 10 May 2021 13:56:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AEEB610CA for ; Mon, 10 May 2021 13:56:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243449AbhEJNyZ (ORCPT ); Mon, 10 May 2021 09:54:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:51058 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238023AbhEJNv5 (ORCPT ); Mon, 10 May 2021 09:51:57 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 91C2C6143C; Mon, 10 May 2021 13:49:24 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lg6Hi-000Rol-Nc; Mon, 10 May 2021 14:49:22 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: James Morse , Suzuki K Poulose , Alexandru Elisei , Eric Auger , Hector Martin , Mark Rutland , kernel-team@android.com Subject: [PATCH v3 6/9] KVM: arm64: vgic: Implement SW-driven deactivation Date: Mon, 10 May 2021 14:48:21 +0100 Message-Id: <20210510134824.1910399-7-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210510134824.1910399-1-maz@kernel.org> References: <20210510134824.1910399-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, eric.auger@redhat.com, marcan@marcan.st, mark.rutland@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In order to deal with these systems that do not offer HW-based deactivation of interrupts, let implement a SW-based approach: - When the irq is queued into a LR, treat it as a pure virtual interrupt and set the EOI flag in the LR. - When the interrupt state is read back from the LR, force a deactivation when the state is invalid (neither active nor pending) Interrupts requiring such treatment get the VGIC_SW_RESAMPLE flag. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/vgic/vgic-v2.c | 19 +++++++++++++++---- arch/arm64/kvm/vgic/vgic-v3.c | 19 +++++++++++++++---- include/kvm/arm_vgic.h | 10 ++++++++++ 3 files changed, 40 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c index 11934c2af2f4..2c580204f1dc 100644 --- a/arch/arm64/kvm/vgic/vgic-v2.c +++ b/arch/arm64/kvm/vgic/vgic-v2.c @@ -108,11 +108,22 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) * If this causes us to lower the level, we have to also clear * the physical active state, since we will otherwise never be * told when the interrupt becomes asserted again. + * + * Another case is when the interrupt requires a helping hand + * on deactivation (no HW deactivation, for example). */ - if (vgic_irq_is_mapped_level(irq) && (val & GICH_LR_PENDING_BIT)) { - irq->line_level = vgic_get_phys_line_level(irq); + if (vgic_irq_is_mapped_level(irq)) { + bool resample = false; + + if (val & GICH_LR_PENDING_BIT) { + irq->line_level = vgic_get_phys_line_level(irq); + resample = !irq->line_level; + } else if (vgic_irq_needs_resampling(irq) && + !(irq->active || irq->pending_latch)) { + resample = true; + } - if (!irq->line_level) + if (resample) vgic_irq_set_phys_active(irq, false); } @@ -152,7 +163,7 @@ void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr) if (irq->group) val |= GICH_LR_GROUP1; - if (irq->hw) { + if (irq->hw && !vgic_irq_needs_resampling(irq)) { val |= GICH_LR_HW; val |= irq->hwintid << GICH_LR_PHYSID_CPUID_SHIFT; /* diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 41ecf219c333..66004f61cd83 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -101,11 +101,22 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) * If this causes us to lower the level, we have to also clear * the physical active state, since we will otherwise never be * told when the interrupt becomes asserted again. + * + * Another case is when the interrupt requires a helping hand + * on deactivation (no HW deactivation, for example). */ - if (vgic_irq_is_mapped_level(irq) && (val & ICH_LR_PENDING_BIT)) { - irq->line_level = vgic_get_phys_line_level(irq); + if (vgic_irq_is_mapped_level(irq)) { + bool resample = false; + + if (val & ICH_LR_PENDING_BIT) { + irq->line_level = vgic_get_phys_line_level(irq); + resample = !irq->line_level; + } else if (vgic_irq_needs_resampling(irq) && + !(irq->active || irq->pending_latch)) { + resample = true; + } - if (!irq->line_level) + if (resample) vgic_irq_set_phys_active(irq, false); } @@ -136,7 +147,7 @@ void vgic_v3_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr) } } - if (irq->hw) { + if (irq->hw && !vgic_irq_needs_resampling(irq)) { val |= ICH_LR_HW; val |= ((u64)irq->hwintid) << ICH_LR_PHYS_ID_SHIFT; /* diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index e5f06df000f2..e602d848fc1a 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -99,6 +99,11 @@ enum vgic_irq_config { * kvm_arm_get_running_vcpu() to get the vcpu pointer for private IRQs. */ struct irq_ops { + /* Per interrupt flags for special-cased interrupts */ + unsigned long flags; + +#define VGIC_IRQ_SW_RESAMPLE BIT(0) /* Clear the active state for resampling */ + /* * Callback function pointer to in-kernel devices that can tell us the * state of the input level of mapped level-triggered IRQ faster than @@ -150,6 +155,11 @@ struct vgic_irq { for in-kernel devices. */ }; +static inline bool vgic_irq_needs_resampling(struct vgic_irq *irq) +{ + return irq->ops && (irq->ops->flags & VGIC_IRQ_SW_RESAMPLE); +} + struct vgic_register_region; struct vgic_its; -- 2.29.2