Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752611AbdFOMyu (ORCPT ); Thu, 15 Jun 2017 08:54:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56708 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752116AbdFOMys (ORCPT ); Thu, 15 Jun 2017 08:54:48 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com CB1DE804F7 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=eric.auger@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com CB1DE804F7 From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, alex.williamson@redhat.com, b.reynal@virtualopensystems.com, pbonzini@redhat.com, marc.zyngier@arm.com, christoffer.dall@linaro.org Cc: drjones@redhat.com, wei@redhat.com Subject: [PATCH v2 3/8] VFIO: platform: Direct EOI irq bypass for ARM/ARM64 Date: Thu, 15 Jun 2017 14:52:35 +0200 Message-Id: <1497531160-29162-4-git-send-email-eric.auger@redhat.com> In-Reply-To: <1497531160-29162-1-git-send-email-eric.auger@redhat.com> References: <1497531160-29162-1-git-send-email-eric.auger@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Thu, 15 Jun 2017 12:54:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9203 Lines: 286 This patch adds the registration/unregistration of an irq_bypass_producer for vfio platform device interrupts. Its callbacks handle the direct EOI modality on VFIO side. - stop/start: disable/enable the host irq - add/del consumer: set the VFIO Direct EOI mode, ie. select the adapted physical IRQ handler (automasked or not automasked). Signed-off-by: Eric Auger --- v1 -> v2: - add a comment explaining we allow direct EOI for edge sensitive interrupts without modifying the physical IRQ handler. --- drivers/vfio/platform/Kconfig | 5 + drivers/vfio/platform/Makefile | 2 +- drivers/vfio/platform/vfio_platform_irq.c | 19 ++++ drivers/vfio/platform/vfio_platform_irq_bypass.c | 118 +++++++++++++++++++++++ drivers/vfio/platform/vfio_platform_private.h | 22 +++++ 5 files changed, 165 insertions(+), 1 deletion(-) create mode 100644 drivers/vfio/platform/vfio_platform_irq_bypass.c diff --git a/drivers/vfio/platform/Kconfig b/drivers/vfio/platform/Kconfig index bb30128..33ec3d9 100644 --- a/drivers/vfio/platform/Kconfig +++ b/drivers/vfio/platform/Kconfig @@ -2,6 +2,7 @@ config VFIO_PLATFORM tristate "VFIO support for platform devices" depends on VFIO && EVENTFD && (ARM || ARM64) select VFIO_VIRQFD + select IRQ_BYPASS_MANAGER help Support for platform devices with VFIO. This is required to make use of platform devices present on the system using the VFIO @@ -19,4 +20,8 @@ config VFIO_AMBA If you don't know what to do here, say N. +config VFIO_PLATFORM_IRQ_BYPASS_DEOI + depends on VFIO_PLATFORM + def_bool y + source "drivers/vfio/platform/reset/Kconfig" diff --git a/drivers/vfio/platform/Makefile b/drivers/vfio/platform/Makefile index 41a6224..324f3e7 100644 --- a/drivers/vfio/platform/Makefile +++ b/drivers/vfio/platform/Makefile @@ -1,4 +1,4 @@ -vfio-platform-base-y := vfio_platform_common.o vfio_platform_irq.o +vfio-platform-base-y := vfio_platform_common.o vfio_platform_irq.o vfio_platform_irq_bypass.o vfio-platform-y := vfio_platform.o obj-$(CONFIG_VFIO_PLATFORM) += vfio-platform.o diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c index 0228a96..452dc3d 100644 --- a/drivers/vfio/platform/vfio_platform_irq.c +++ b/drivers/vfio/platform/vfio_platform_irq.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "vfio_platform_private.h" @@ -186,6 +187,19 @@ static irqreturn_t vfio_wrapper_handler(int irq, void *dev_id) return ret; } +/* must be called with irq_ctx->lock held */ +int vfio_platform_set_deoi(struct vfio_platform_irq *irq_ctx, bool deoi) +{ + irq_ctx->deoi = deoi; + + if (!deoi && (irq_ctx->flags & VFIO_IRQ_INFO_AUTOMASKED)) + irq_ctx->handler = vfio_automasked_irq_handler; + else + irq_ctx->handler = vfio_irq_handler; + + return 0; +} + static int vfio_set_trigger(struct vfio_platform_device *vdev, int index, int fd, irq_handler_t handler) { @@ -196,6 +210,7 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index, if (irq->trigger) { irq_clear_status_flags(irq->hwirq, IRQ_NOAUTOEN); free_irq(irq->hwirq, irq); + irq_bypass_unregister_producer(&irq->producer); kfree(irq->name); eventfd_ctx_put(irq->trigger); irq->trigger = NULL; @@ -227,6 +242,10 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index, return ret; } + if (vfio_platform_has_deoi()) + vfio_platform_register_deoi_producer(vdev, irq, + trigger, irq->hwirq); + if (!irq->usermasked) enable_irq(irq->hwirq); diff --git a/drivers/vfio/platform/vfio_platform_irq_bypass.c b/drivers/vfio/platform/vfio_platform_irq_bypass.c new file mode 100644 index 0000000..692b081 --- /dev/null +++ b/drivers/vfio/platform/vfio_platform_irq_bypass.c @@ -0,0 +1,118 @@ +/* + * VFIO platform device irqbypass callback implementation for DEOI + * + * Copyright (C) 2017 Red Hat, Inc. All rights reserved. + * Author: Eric Auger + * + * 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. + */ + +#include +#include +#include +#include +#include "vfio_platform_private.h" + +#ifdef CONFIG_VFIO_PLATFORM_IRQ_BYPASS_DEOI + +static void irq_bypass_deoi_start(struct irq_bypass_producer *prod) +{ + enable_irq(prod->irq); +} + +static void irq_bypass_deoi_stop(struct irq_bypass_producer *prod) +{ + disable_irq(prod->irq); +} + +/** + * irq_bypass_deoi_add_consumer - turns irq direct EOI on + * + * The linux irq is disabled when the function is called. + * The operation succeeds only if the irq is not active at irqchip level + * and the irq is not automasked at VFIO level, meaning the IRQ is under + * injection into the guest. + */ +static int irq_bypass_deoi_add_consumer(struct irq_bypass_producer *prod, + struct irq_bypass_consumer *cons) +{ + struct vfio_platform_irq *irq_ctx = + container_of(prod, struct vfio_platform_irq, producer); + unsigned long flags; + bool active; + int ret; + + spin_lock_irqsave(&irq_ctx->lock, flags); + + ret = irq_get_irqchip_state(irq_ctx->hwirq, IRQCHIP_STATE_ACTIVE, + &active); + if (ret) + goto out; + + if (active || irq_ctx->automasked) { + ret = -EAGAIN; + goto out; + } + + /* + * Direct EOI is enabled for edge sensitive interrupts without any + * change with respect to the physical interrupt handler + */ + if (!(irq_get_trigger_type(irq_ctx->hwirq) & IRQ_TYPE_LEVEL_MASK)) + goto out; + + ret = vfio_platform_set_deoi(irq_ctx, true); +out: + spin_unlock_irqrestore(&irq_ctx->lock, flags); + return ret; +} + +static void irq_bypass_deoi_del_consumer(struct irq_bypass_producer *prod, + struct irq_bypass_consumer *cons) +{ + struct vfio_platform_irq *irq_ctx = + container_of(prod, struct vfio_platform_irq, producer); + unsigned long flags; + + spin_lock_irqsave(&irq_ctx->lock, flags); + if (irq_get_trigger_type(irq_ctx->hwirq) & IRQ_TYPE_LEVEL_MASK) + vfio_platform_set_deoi(irq_ctx, false); + spin_unlock_irqrestore(&irq_ctx->lock, flags); +} + +bool vfio_platform_has_deoi(void) +{ + return true; +} + +void vfio_platform_register_deoi_producer(struct vfio_platform_device *vdev, + struct vfio_platform_irq *irq, + struct eventfd_ctx *trigger, + unsigned int host_irq) +{ + struct irq_bypass_producer *prod = &irq->producer; + int ret; + + prod->token = trigger; + prod->irq = host_irq; + prod->add_consumer = irq_bypass_deoi_add_consumer; + prod->del_consumer = irq_bypass_deoi_del_consumer; + prod->stop = irq_bypass_deoi_stop; + prod->start = irq_bypass_deoi_start; + + ret = irq_bypass_register_producer(prod); + if (unlikely(ret)) + dev_info(vdev->device, + "irq bypass producer (token %p) registration fails: %d\n", + prod->token, ret); +} + +#endif + diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h index 66a9ef5..ab85c58 100644 --- a/drivers/vfio/platform/vfio_platform_private.h +++ b/drivers/vfio/platform/vfio_platform_private.h @@ -17,6 +17,7 @@ #include #include +#include #define VFIO_PLATFORM_OFFSET_SHIFT 40 #define VFIO_PLATFORM_OFFSET_MASK (((u64)(1) << VFIO_PLATFORM_OFFSET_SHIFT) - 1) @@ -40,6 +41,7 @@ struct vfio_platform_irq { struct virqfd *mask; bool deoi; irqreturn_t (*handler)(int irq, void *dev_id); + struct irq_bypass_producer producer; }; struct vfio_platform_region { @@ -102,12 +104,32 @@ extern int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev, unsigned start, unsigned count, void *data); +extern int vfio_platform_set_deoi(struct vfio_platform_irq *irq_ctx, bool deoi); + extern void __vfio_platform_register_reset(struct vfio_platform_reset_node *n); extern void vfio_platform_unregister_reset(const char *compat, vfio_platform_reset_fn_t fn); #define is_masked(irq) ((irq)->usermasked || (irq)->automasked) +#ifdef CONFIG_VFIO_PLATFORM_IRQ_BYPASS_DEOI +bool vfio_platform_has_deoi(void); +void vfio_platform_register_deoi_producer(struct vfio_platform_device *vdev, + struct vfio_platform_irq *irq, + struct eventfd_ctx *trigger, + unsigned int host_irq); +#else +static inline bool vfio_platform_has_deoi(void) +{ + return false; +} +static inline +void vfio_platform_register_deoi_producer(struct vfio_platform_device *vdev, + struct vfio_platform_irq *irq, + struct eventfd_ctx *trigger, + unsigned int host_irq) {} +#endif + #define vfio_platform_register_reset(__compat, __reset) \ static struct vfio_platform_reset_node __reset ## _node = { \ .owner = THIS_MODULE, \ -- 2.5.5