From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian King Subject: Re: [PATCH 0/3] PCI: Rework config space locking, add INTx masking services Date: Fri, 14 Oct 2011 10:44:11 -0500 Message-ID: <4E9858CB.7080005@linux.vnet.ibm.com> References: <20111006084853.033d8d0f@jbarnes-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Jan Kiszka , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, "Hans J. Koch" , Greg Kroah-Hartman , "Michael S. Tsirkin" , kvm@vger.kernel.org To: Jesse Barnes Return-path: In-Reply-To: <20111006084853.033d8d0f@jbarnes-desktop> Sender: linux-pci-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 10/06/2011 10:48 AM, Jesse Barnes wrote: > On Mon, 12 Sep 2011 18:54:01 +0200 > Jan Kiszka wrote: > >> This series tries to heal the currently broken locking scheme around PCI >> config space accesses. >> >> We have an interface lock out access via sysfs, but that service wrongly >> assumes it is only called by one instance at a time for some device. So >> two loops doing >> >> echo 1 > /sys/bus/pci/devices//reset >> >> in parallel will trigger a kernel BUG at the moment. >> >> Besides synchronizing with user space, we also need to manage config >> space access of generic PCI drivers. They need to mask legacy interrupt >> lines while the specific driver runs in user space or a guest OS. >> >> The approach taken here is provide mutex-like locking for general >> access - which still requires a special mechanism due to requirements of >> the IBM Power RAID SCSI driver. Furthermore, INTx masking is now >> available via the PCI core and synchronized via the internal pci_lock. >> >> Not sure who may want to take this, so I'm CC'ing broadly. > > ISTR a bunch of discussion about this (just back from lots of work > travel and vacation, sorry I missed most of it). > > Is this the agreed upon way of handling it? If so, can I get some > Reviewed/Acked-bys from people? Acked-by: Brian King -- Brian King Linux on Power Virtualization IBM Linux Technology Center