Re: [PATCH v3 00/15] IOMMUFD Generic interface

From: Jason Gunthorpe <jgg@nvidia.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>,
	bpf@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
	David Woodhouse <dwmw2@infradead.org>,
	iommu@lists.linux.dev, Joerg Roedel <joro@8bytes.org>,
	Kevin Tian <kevin.tian@intel.com>,
	linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org,
	llvm@lists.linux.dev, Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Miguel Ojeda <ojeda@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Shuah Khan <shuah@kernel.org>,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
	Tom Rix <trix@redhat.com>, Will Deacon <will@kernel.org>,
	Chaitanya Kulkarni <chaitanyak@nvidia.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Daniel Jordan <daniel.m.jordan@oracle.com>,
	David Gibson <david@gibson.dropbear.id.au>,
	Eric Auger <eric.auger@redhat.com>,
	Eric Farman <farman@linux.ibm.com>,
	Jason Wang <jasowang@redhat.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Joao Martins <joao.m.martins@oracle.com>,
	kvm@vger.kernel.org, Matthew Rosato <mjrosato@linux.ibm.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Nicolin Chen <nicolinc@nvidia.com>,
	Niklas Schnelle <schnelle@linux.ibm.com>,
	Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>,
	Yi Liu <yi.l.liu@intel.com>, Keqian Zhu <zhukeqian1@huawei.com>
Subject: Re: [PATCH v3 00/15] IOMMUFD Generic interface
Date: Mon, 7 Nov 2022 10:19:41 -0400	[thread overview]
Message-ID: <Y2kT/Qb35wI/Pnh5@nvidia.com> (raw)
In-Reply-To: <20221104152713.3ae1c409.alex.williamson@redhat.com>

On Fri, Nov 04, 2022 at 03:27:13PM -0600, Alex Williamson wrote:
> On Tue, 25 Oct 2022 15:12:09 -0300
> Jason Gunthorpe <jgg@nvidia.com> wrote:
> 
> > [
> > At this point everything is done and I will start putting this work into a
> > git tree and into linux-next with the intention of sending it during the
> > next merge window.
> > 
> > I intend to focus the next several weeks on more intensive QA to look at
> > error flows and other things. Hopefully including syzkaller if I'm lucky
> > ]
> 
> In case this one hasn't been reported yet (with IOMMUFD_VFIO_CONTAINER):
> 
> ======================================================
> WARNING: possible circular locking dependency detected
> 6.1.0-rc3+ #133 Tainted: G            E     
> ------------------------------------------------------
> qemu-system-x86/1731 is trying to acquire lock:
> ffff90d3f5fe3e08 (&iopt->iova_rwsem){++++}-{3:3}, at: iopt_map_pages.part.0+0x85/0xe0 [iommufd]
> 
> but task is already holding lock:
> ffff90d3f5fe3d18 (&iopt->domains_rwsem){.+.+}-{3:3}, at: iopt_map_pages.part.0+0x18/0xe0 [iommufd]
> 
> which lock already depends on the new lock.

I think this is:

https://lore.kernel.org/all/Y1qR6Zxdmuk+ME5z@nvidia.com/

Thanks,
Jason