From patchwork Sat Mar 6 16:18:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 12120135 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 721B8C433DB for ; Sat, 6 Mar 2021 16:18:48 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 32D7664FCF for ; Sat, 6 Mar 2021 16:18:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 32D7664FCF Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.94313.177827 (Exim 4.92) (envelope-from ) id 1lIZdX-0002CW-JY; Sat, 06 Mar 2021 16:18:39 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 94313.177827; Sat, 06 Mar 2021 16:18:39 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lIZdX-0002CP-Fv; Sat, 06 Mar 2021 16:18:39 +0000 Received: by outflank-mailman (input) for mailman id 94313; Sat, 06 Mar 2021 16:18:38 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lIZdW-0002AY-8W for xen-devel@lists.xenproject.org; Sat, 06 Mar 2021 16:18:38 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id bbb3be79-3cfa-4512-9c61-43b89fee4dcd; Sat, 06 Mar 2021 16:18:36 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 145CAAD21; Sat, 6 Mar 2021 16:18:36 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: bbb3be79-3cfa-4512-9c61-43b89fee4dcd X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1615047516; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2ItonbQ6nCPS7Ck5aiQWROygJkg9zRoVzDQtkeXBTtM=; b=JhoxF/rLRC/zhQd/M2ReBsjMPiviL+iHuN29hmSxhE0B1CUwZAKjKJkmDUPqKujfXLAe7N d2cUZ2P3gSf3h6YpLMaCnlwxPBZmnNlHQbTQiOmE+vG2picUlslwGjePGYejzswWnohDS3 xhPiD2RK+Hc6oMqbvpjG0IngwUoJVrk= From: Juergen Gross To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Juergen Gross , Boris Ostrovsky , Stefano Stabellini , stable@vger.kernel.org, Julien Grall , Julien Grall Subject: [PATCH v4 2/3] xen/events: don't unmask an event channel when an eoi is pending Date: Sat, 6 Mar 2021 17:18:32 +0100 Message-Id: <20210306161833.4552-3-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210306161833.4552-1-jgross@suse.com> References: <20210306161833.4552-1-jgross@suse.com> MIME-Version: 1.0 An event channel should be kept masked when an eoi is pending for it. When being migrated to another cpu it might be unmasked, though. In order to avoid this keep three different flags for each event channel to be able to distinguish "normal" masking/unmasking from eoi related masking/unmasking and temporary masking. The event channel should only be able to generate an interrupt if all flags are cleared. Cc: stable@vger.kernel.org Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn framework") Reported-by: Julien Grall Signed-off-by: Juergen Gross Reviewed-by: Julien Grall Reviewed-by: Boris Ostrovsky Tested-by: Ross Lagerwall --- V2: - introduce a lock around masking/unmasking - merge patch 3 into this one (Jan Beulich) V4: - don't set eoi masking flag in lateeoi_mask_ack_dynirq() --- drivers/xen/events/events_2l.c | 7 -- drivers/xen/events/events_base.c | 101 +++++++++++++++++++++------ drivers/xen/events/events_fifo.c | 7 -- drivers/xen/events/events_internal.h | 6 -- 4 files changed, 80 insertions(+), 41 deletions(-) diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c index a7f413c5c190..b8f2f971c2f0 100644 --- a/drivers/xen/events/events_2l.c +++ b/drivers/xen/events/events_2l.c @@ -77,12 +77,6 @@ static bool evtchn_2l_is_pending(evtchn_port_t port) return sync_test_bit(port, BM(&s->evtchn_pending[0])); } -static bool evtchn_2l_test_and_set_mask(evtchn_port_t port) -{ - struct shared_info *s = HYPERVISOR_shared_info; - return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0])); -} - static void evtchn_2l_mask(evtchn_port_t port) { struct shared_info *s = HYPERVISOR_shared_info; @@ -376,7 +370,6 @@ static const struct evtchn_ops evtchn_ops_2l = { .clear_pending = evtchn_2l_clear_pending, .set_pending = evtchn_2l_set_pending, .is_pending = evtchn_2l_is_pending, - .test_and_set_mask = evtchn_2l_test_and_set_mask, .mask = evtchn_2l_mask, .unmask = evtchn_2l_unmask, .handle_events = evtchn_2l_handle_events, diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 7e23808892a7..b27c012c86b5 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -98,13 +98,18 @@ struct irq_info { short refcnt; u8 spurious_cnt; u8 is_accounted; - enum xen_irq_type type; /* type */ + short type; /* type: IRQT_* */ + u8 mask_reason; /* Why is event channel masked */ +#define EVT_MASK_REASON_EXPLICIT 0x01 +#define EVT_MASK_REASON_TEMPORARY 0x02 +#define EVT_MASK_REASON_EOI_PENDING 0x04 unsigned irq; evtchn_port_t evtchn; /* event channel */ unsigned short cpu; /* cpu bound */ unsigned short eoi_cpu; /* EOI must happen on this cpu-1 */ unsigned int irq_epoch; /* If eoi_cpu valid: irq_epoch of event */ u64 eoi_time; /* Time in jiffies when to EOI. */ + spinlock_t lock; union { unsigned short virq; @@ -154,6 +159,7 @@ static DEFINE_RWLOCK(evtchn_rwlock); * evtchn_rwlock * IRQ-desc lock * percpu eoi_list_lock + * irq_info->lock */ static LIST_HEAD(xen_irq_list_head); @@ -304,6 +310,8 @@ static int xen_irq_info_common_setup(struct irq_info *info, info->irq = irq; info->evtchn = evtchn; info->cpu = cpu; + info->mask_reason = EVT_MASK_REASON_EXPLICIT; + spin_lock_init(&info->lock); ret = set_evtchn_to_irq(evtchn, irq); if (ret < 0) @@ -459,6 +467,34 @@ unsigned int cpu_from_evtchn(evtchn_port_t evtchn) return ret; } +static void do_mask(struct irq_info *info, u8 reason) +{ + unsigned long flags; + + spin_lock_irqsave(&info->lock, flags); + + if (!info->mask_reason) + mask_evtchn(info->evtchn); + + info->mask_reason |= reason; + + spin_unlock_irqrestore(&info->lock, flags); +} + +static void do_unmask(struct irq_info *info, u8 reason) +{ + unsigned long flags; + + spin_lock_irqsave(&info->lock, flags); + + info->mask_reason &= ~reason; + + if (!info->mask_reason) + unmask_evtchn(info->evtchn); + + spin_unlock_irqrestore(&info->lock, flags); +} + #ifdef CONFIG_X86 static bool pirq_check_eoi_map(unsigned irq) { @@ -605,7 +641,7 @@ static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious) } info->eoi_time = 0; - unmask_evtchn(evtchn); + do_unmask(info, EVT_MASK_REASON_EOI_PENDING); } static void xen_irq_lateeoi_worker(struct work_struct *work) @@ -850,7 +886,8 @@ static unsigned int __startup_pirq(unsigned int irq) goto err; out: - unmask_evtchn(evtchn); + do_unmask(info, EVT_MASK_REASON_EXPLICIT); + eoi_pirq(irq_get_irq_data(irq)); return 0; @@ -877,7 +914,7 @@ static void shutdown_pirq(struct irq_data *data) if (!VALID_EVTCHN(evtchn)) return; - mask_evtchn(evtchn); + do_mask(info, EVT_MASK_REASON_EXPLICIT); xen_evtchn_close(evtchn); xen_irq_info_cleanup(info); } @@ -1721,10 +1758,10 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq) } /* Rebind an evtchn so that it gets delivered to a specific cpu */ -static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu) +static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu) { struct evtchn_bind_vcpu bind_vcpu; - int masked; + evtchn_port_t evtchn = info ? info->evtchn : 0; if (!VALID_EVTCHN(evtchn)) return -1; @@ -1740,7 +1777,7 @@ static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu) * Mask the event while changing the VCPU binding to prevent * it being delivered on an unexpected VCPU. */ - masked = test_and_set_mask(evtchn); + do_mask(info, EVT_MASK_REASON_TEMPORARY); /* * If this fails, it usually just indicates that we're dealing with a @@ -1750,8 +1787,7 @@ static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu) if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0) bind_evtchn_to_cpu(evtchn, tcpu, false); - if (!masked) - unmask_evtchn(evtchn); + do_unmask(info, EVT_MASK_REASON_TEMPORARY); return 0; } @@ -1790,7 +1826,7 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest, unsigned int tcpu = select_target_cpu(dest); int ret; - ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu); + ret = xen_rebind_evtchn_to_cpu(info_for_irq(data->irq), tcpu); if (!ret) irq_data_update_effective_affinity(data, cpumask_of(tcpu)); @@ -1799,18 +1835,20 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest, static void enable_dynirq(struct irq_data *data) { - evtchn_port_t evtchn = evtchn_from_irq(data->irq); + struct irq_info *info = info_for_irq(data->irq); + evtchn_port_t evtchn = info ? info->evtchn : 0; if (VALID_EVTCHN(evtchn)) - unmask_evtchn(evtchn); + do_unmask(info, EVT_MASK_REASON_EXPLICIT); } static void disable_dynirq(struct irq_data *data) { - evtchn_port_t evtchn = evtchn_from_irq(data->irq); + struct irq_info *info = info_for_irq(data->irq); + evtchn_port_t evtchn = info ? info->evtchn : 0; if (VALID_EVTCHN(evtchn)) - mask_evtchn(evtchn); + do_mask(info, EVT_MASK_REASON_EXPLICIT); } static void ack_dynirq(struct irq_data *data) @@ -1829,18 +1867,39 @@ static void mask_ack_dynirq(struct irq_data *data) ack_dynirq(data); } +static void lateeoi_ack_dynirq(struct irq_data *data) +{ + struct irq_info *info = info_for_irq(data->irq); + evtchn_port_t evtchn = info ? info->evtchn : 0; + + if (VALID_EVTCHN(evtchn)) { + do_mask(info, EVT_MASK_REASON_EOI_PENDING); + clear_evtchn(evtchn); + } +} + +static void lateeoi_mask_ack_dynirq(struct irq_data *data) +{ + struct irq_info *info = info_for_irq(data->irq); + evtchn_port_t evtchn = info ? info->evtchn : 0; + + if (VALID_EVTCHN(evtchn)) { + do_mask(info, EVT_MASK_REASON_EXPLICIT); + clear_evtchn(evtchn); + } +} + static int retrigger_dynirq(struct irq_data *data) { - evtchn_port_t evtchn = evtchn_from_irq(data->irq); - int masked; + struct irq_info *info = info_for_irq(data->irq); + evtchn_port_t evtchn = info ? info->evtchn : 0; if (!VALID_EVTCHN(evtchn)) return 0; - masked = test_and_set_mask(evtchn); + do_mask(info, EVT_MASK_REASON_TEMPORARY); set_evtchn(evtchn); - if (!masked) - unmask_evtchn(evtchn); + do_unmask(info, EVT_MASK_REASON_TEMPORARY); return 1; } @@ -2054,8 +2113,8 @@ static struct irq_chip xen_lateeoi_chip __read_mostly = { .irq_mask = disable_dynirq, .irq_unmask = enable_dynirq, - .irq_ack = mask_ack_dynirq, - .irq_mask_ack = mask_ack_dynirq, + .irq_ack = lateeoi_ack_dynirq, + .irq_mask_ack = lateeoi_mask_ack_dynirq, .irq_set_affinity = set_affinity_irq, .irq_retrigger = retrigger_dynirq, diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c index b234f1766810..ad9fe51d3fb3 100644 --- a/drivers/xen/events/events_fifo.c +++ b/drivers/xen/events/events_fifo.c @@ -209,12 +209,6 @@ static bool evtchn_fifo_is_pending(evtchn_port_t port) return sync_test_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word)); } -static bool evtchn_fifo_test_and_set_mask(evtchn_port_t port) -{ - event_word_t *word = event_word_from_port(port); - return sync_test_and_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word)); -} - static void evtchn_fifo_mask(evtchn_port_t port) { event_word_t *word = event_word_from_port(port); @@ -423,7 +417,6 @@ static const struct evtchn_ops evtchn_ops_fifo = { .clear_pending = evtchn_fifo_clear_pending, .set_pending = evtchn_fifo_set_pending, .is_pending = evtchn_fifo_is_pending, - .test_and_set_mask = evtchn_fifo_test_and_set_mask, .mask = evtchn_fifo_mask, .unmask = evtchn_fifo_unmask, .handle_events = evtchn_fifo_handle_events, diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h index 18a4090d0709..4d3398eff9cd 100644 --- a/drivers/xen/events/events_internal.h +++ b/drivers/xen/events/events_internal.h @@ -21,7 +21,6 @@ struct evtchn_ops { void (*clear_pending)(evtchn_port_t port); void (*set_pending)(evtchn_port_t port); bool (*is_pending)(evtchn_port_t port); - bool (*test_and_set_mask)(evtchn_port_t port); void (*mask)(evtchn_port_t port); void (*unmask)(evtchn_port_t port); @@ -84,11 +83,6 @@ static inline bool test_evtchn(evtchn_port_t port) return evtchn_ops->is_pending(port); } -static inline bool test_and_set_mask(evtchn_port_t port) -{ - return evtchn_ops->test_and_set_mask(port); -} - static inline void mask_evtchn(evtchn_port_t port) { return evtchn_ops->mask(port);