Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751581AbcLEQx3 (ORCPT ); Mon, 5 Dec 2016 11:53:29 -0500 Received: from mail-pg0-f53.google.com ([74.125.83.53]:33291 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751378AbcLEQx1 (ORCPT ); Mon, 5 Dec 2016 11:53:27 -0500 Date: Mon, 5 Dec 2016 08:52:40 -0800 From: Stephen Hemminger To: Long Li Cc: "K. Y. Srinivasan" , Haiyang Zhang , Bjorn Helgaas , devel@linuxdriverproject.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH] pci-hyperv: use kmalloc to allocate hypercall params buffer Message-ID: <20161205085240.23f686fc@xeon-e3> In-Reply-To: <1478642678-31659-1-git-send-email-longli@exchange.microsoft.com> References: <1478642678-31659-1-git-send-email-longli@exchange.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1268 Lines: 30 On Tue, 8 Nov 2016 14:04:38 -0800 Long Li wrote: > + spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags); > + > + params = &hbus->retarget_msi_interrupt_params; > + memset(params, 0, sizeof(*params)); > + params->partition_id = HV_PARTITION_ID_SELF; > + params->source = 1; /* MSI(-X) */ > + params->address = msi_desc->msg.address_lo; > + params->data = msi_desc->msg.data; > + params->device_id = (hbus->hdev->dev_instance.b[5] << 24) | > (hbus->hdev->dev_instance.b[4] << 16) | > (hbus->hdev->dev_instance.b[7] << 8) | > (hbus->hdev->dev_instance.b[6] & 0xf8) | > PCI_FUNC(pdev->devfn); > - params.vector = cfg->vector; > + params->vector = cfg->vector; > > for_each_cpu_and(cpu, dest, cpu_online_mask) > - params.vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu)); > + params->vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu)); > + > + hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, params, NULL); > > - hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, ¶ms, NULL); > + spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags); It looks like the additional locking here is being overly paranoid. The caller is already holding the irq descriptor lock. Look at fixup_irqs.