From patchwork Fri May 17 10:47:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 10947727 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9376814C0 for ; Fri, 17 May 2019 10:48:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7E05D26E47 for ; Fri, 17 May 2019 10:48:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7152526E4F; Fri, 17 May 2019 10:48:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C77D226E47 for ; Fri, 17 May 2019 10:48:49 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hRaOX-0005Vy-Rg; Fri, 17 May 2019 10:47:21 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hRaOW-0005Vn-IA for xen-devel@lists.xenproject.org; Fri, 17 May 2019 10:47:20 +0000 X-Inumbo-ID: 2423d8cb-7891-11e9-8980-bc764e045a96 Received: from prv1-mh.provo.novell.com (unknown [137.65.248.33]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTPS id 2423d8cb-7891-11e9-8980-bc764e045a96; Fri, 17 May 2019 10:47:18 +0000 (UTC) Received: from INET-PRV1-MTA by prv1-mh.provo.novell.com with Novell_GroupWise; Fri, 17 May 2019 04:47:17 -0600 Message-Id: <5CDE91360200007800230075@prv1-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 18.1.0 Date: Fri, 17 May 2019 04:47:18 -0600 From: "Jan Beulich" To: "xen-devel" References: <5CC6DD090200007800229E80@prv1-mh.provo.novell.com> <5CDE8F5B020000780023005F@prv1-mh.provo.novell.com> In-Reply-To: <5CDE8F5B020000780023005F@prv1-mh.provo.novell.com> Mime-Version: 1.0 Content-Disposition: inline Subject: [Xen-devel] [PATCH v3 05/15] x86/IRQ: consolidate use of ->arch.cpu_mask X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Andrew Cooper , Wei Liu , Roger Pau Monne Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Mixed meaning was implied so far by different pieces of code - disagreement was in particular about whether to expect offline CPUs' bits to possibly be set. Switch to a mostly consistent meaning (exception being high priority interrupts, which would perhaps better be switched to the same model as well in due course). Use the field to record the vector allocation mask, i.e. potentially including bits of offline (parked) CPUs. This implies that before passing the mask to certain functions (most notably cpu_mask_to_apicid()) it needs to be further reduced to the online subset. The exception of high priority interrupts is also why for the moment _bind_irq_vector() is left as is, despite looking wrong: It's used exclusively for IRQ0, which isn't supposed to move off CPU0 at any time. The prior lack of restricting to online CPUs in set_desc_affinity() before calling cpu_mask_to_apicid() in particular allowed (in x2APIC clustered mode) offlined CPUs to end up enabled in an IRQ's destination field. (I wonder whether vector_allocation_cpumask_flat() shouldn't follow a similar model, using cpu_present_map in favor of cpu_online_map.) For IO-APIC code it was definitely wrong to potentially store, as a fallback, TARGET_CPUS (i.e. all online ones) into the field, as that would have caused problems when determining on which CPUs to release vectors when they've gone out of use. Disable interrupts instead when no valid target CPU can be established (which code elsewhere should guarantee to never happen), and log a message in such an unlikely event. Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné Acked-by: Andrew Cooper --- v2: New. --- a/xen/arch/x86/io_apic.c +++ b/xen/arch/x86/io_apic.c @@ -680,7 +680,7 @@ void /*__init*/ setup_ioapic_dest(void) continue; irq = pin_2_irq(irq_entry, ioapic, pin); desc = irq_to_desc(irq); - BUG_ON(cpumask_empty(desc->arch.cpu_mask)); + BUG_ON(!cpumask_intersects(desc->arch.cpu_mask, &cpu_online_map)); set_ioapic_affinity_irq(desc, desc->arch.cpu_mask); } @@ -2194,7 +2194,6 @@ int io_apic_set_pci_routing (int ioapic, { struct irq_desc *desc = irq_to_desc(irq); struct IO_APIC_route_entry entry; - cpumask_t mask; unsigned long flags; int vector; @@ -2229,11 +2228,17 @@ int io_apic_set_pci_routing (int ioapic, return vector; entry.vector = vector; - cpumask_copy(&mask, TARGET_CPUS); - /* Don't chance ending up with an empty mask. */ - if (cpumask_intersects(&mask, desc->arch.cpu_mask)) - cpumask_and(&mask, &mask, desc->arch.cpu_mask); - SET_DEST(entry, logical, cpu_mask_to_apicid(&mask)); + if (cpumask_intersects(desc->arch.cpu_mask, TARGET_CPUS)) { + cpumask_t *mask = this_cpu(scratch_cpumask); + + cpumask_and(mask, desc->arch.cpu_mask, TARGET_CPUS); + SET_DEST(entry, logical, cpu_mask_to_apicid(mask)); + } else { + printk(XENLOG_ERR "IRQ%d: no target CPU (%*pb vs %*pb)\n", + irq, nr_cpu_ids, cpumask_bits(desc->arch.cpu_mask), + nr_cpu_ids, cpumask_bits(TARGET_CPUS)); + desc->status |= IRQ_DISABLED; + } apic_printk(APIC_DEBUG, KERN_DEBUG "IOAPIC[%d]: Set PCI routing entry " "(%d-%d -> %#x -> IRQ %d Mode:%i Active:%i)\n", ioapic, @@ -2419,7 +2424,21 @@ int ioapic_guest_write(unsigned long phy /* Set the vector field to the real vector! */ rte.vector = desc->arch.vector; - SET_DEST(rte, logical, cpu_mask_to_apicid(desc->arch.cpu_mask)); + if ( cpumask_intersects(desc->arch.cpu_mask, TARGET_CPUS) ) + { + cpumask_t *mask = this_cpu(scratch_cpumask); + + cpumask_and(mask, desc->arch.cpu_mask, TARGET_CPUS); + SET_DEST(rte, logical, cpu_mask_to_apicid(mask)); + } + else + { + gprintk(XENLOG_ERR, "IRQ%d: no target CPU (%*pb vs %*pb)\n", + irq, nr_cpu_ids, cpumask_bits(desc->arch.cpu_mask), + nr_cpu_ids, cpumask_bits(TARGET_CPUS)); + desc->status |= IRQ_DISABLED; + rte.mask = 1; + } __ioapic_write_entry(apic, pin, 0, rte); --- a/xen/arch/x86/irq.c +++ b/xen/arch/x86/irq.c @@ -471,11 +471,13 @@ static int __assign_irq_vector( */ static int current_vector = FIRST_DYNAMIC_VECTOR, current_offset = 0; int cpu, err, old_vector; - cpumask_t tmp_mask; vmask_t *irq_used_vectors = NULL; old_vector = irq_to_vector(irq); - if (old_vector > 0) { + if ( old_vector > 0 ) + { + cpumask_t tmp_mask; + cpumask_and(&tmp_mask, mask, &cpu_online_map); if (cpumask_intersects(&tmp_mask, desc->arch.cpu_mask)) { desc->arch.vector = old_vector; @@ -498,7 +500,9 @@ static int __assign_irq_vector( else irq_used_vectors = irq_get_used_vector_mask(irq); - for_each_cpu(cpu, mask) { + for_each_cpu(cpu, mask) + { + const cpumask_t *vec_mask; int new_cpu; int vector, offset; @@ -506,8 +510,7 @@ static int __assign_irq_vector( if (!cpu_online(cpu)) continue; - cpumask_and(&tmp_mask, vector_allocation_cpumask(cpu), - &cpu_online_map); + vec_mask = vector_allocation_cpumask(cpu); vector = current_vector; offset = current_offset; @@ -528,7 +531,7 @@ next: && test_bit(vector, irq_used_vectors) ) goto next; - for_each_cpu(new_cpu, &tmp_mask) + for_each_cpu(new_cpu, vec_mask) if (per_cpu(vector_irq, new_cpu)[vector] >= 0) goto next; /* Found one! */ @@ -547,12 +550,12 @@ next: release_old_vec(desc); } - trace_irq_mask(TRC_HW_IRQ_ASSIGN_VECTOR, irq, vector, &tmp_mask); + trace_irq_mask(TRC_HW_IRQ_ASSIGN_VECTOR, irq, vector, vec_mask); - for_each_cpu(new_cpu, &tmp_mask) + for_each_cpu(new_cpu, vec_mask) per_cpu(vector_irq, new_cpu)[vector] = irq; desc->arch.vector = vector; - cpumask_copy(desc->arch.cpu_mask, &tmp_mask); + cpumask_copy(desc->arch.cpu_mask, vec_mask); desc->arch.used = IRQ_USED; ASSERT((desc->arch.used_vectors == NULL) @@ -783,6 +786,7 @@ unsigned int set_desc_affinity(struct ir cpumask_copy(desc->affinity, mask); cpumask_and(&dest_mask, mask, desc->arch.cpu_mask); + cpumask_and(&dest_mask, &dest_mask, &cpu_online_map); return cpu_mask_to_apicid(&dest_mask); } --- a/xen/include/asm-x86/irq.h +++ b/xen/include/asm-x86/irq.h @@ -32,6 +32,12 @@ struct irq_desc; struct arch_irq_desc { s16 vector; /* vector itself is only 8 bits, */ s16 old_vector; /* but we use -1 for unassigned */ + /* + * Except for high priority interrupts @cpu_mask may have bits set for + * offline CPUs. Consumers need to be careful to mask this down to + * online ones as necessary. There is supposed to always be a non- + * empty intersection with cpu_online_map. + */ cpumask_var_t cpu_mask; cpumask_var_t old_cpu_mask; cpumask_var_t pending_mask;