From: Christoph Hellwig <hch@infradead.org>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: kwankhede@nvidia.com, corbet@lwn.net, hca@linux.ibm.com,
gor@linux.ibm.com, agordeev@linux.ibm.com,
borntraeger@linux.ibm.com, svens@linux.ibm.com,
zhenyuw@linux.intel.com, zhi.a.wang@intel.com,
jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com,
rodrigo.vivi@intel.com, tvrtko.ursulin@linux.intel.com,
airlied@linux.ie, daniel@ffwll.ch, farman@linux.ibm.com,
mjrosato@linux.ibm.com, pasic@linux.ibm.com,
vneethv@linux.ibm.com, oberpar@linux.ibm.com,
freude@linux.ibm.com, akrowiak@linux.ibm.com,
jjherne@linux.ibm.com, alex.williamson@redhat.com,
cohuck@redhat.com, jgg@nvidia.com, kevin.tian@intel.com,
jchrist@linux.ibm.com, kvm@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-s390@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [RFT][PATCH v1 5/6] vfio/ccw: Add kmap_local_page() for memcpy
Date: Fri, 17 Jun 2022 01:44:30 -0700 [thread overview]
Message-ID: <Yqw+7gM3Lz96UFdz@infradead.org> (raw)
In-Reply-To: <20220616235212.15185-6-nicolinc@nvidia.com>
On Thu, Jun 16, 2022 at 04:52:11PM -0700, Nicolin Chen wrote:
> The pinned PFN list returned from vfio_pin_pages() is simply converted
> using page_to_pfn() without protection, so direct access via memcpy()
> will crash on S390 if the PFN is an IO PFN. Instead, the pages should
> be touched using kmap_local_page().
I don't see how this helps. kmap_local_page only works for either
pages in the kernel direct map or highmem, but not for memory that needs
to be ioremapped. And there is no highmem on s390.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: mjrosato@linux.ibm.com, linux-doc@vger.kernel.org,
airlied@linux.ie, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, kwankhede@nvidia.com,
vneethv@linux.ibm.com, agordeev@linux.ibm.com,
linux-s390@vger.kernel.org, kvm@vger.kernel.org, corbet@lwn.net,
pasic@linux.ibm.com, jgg@nvidia.com, borntraeger@linux.ibm.com,
intel-gfx@lists.freedesktop.org, jjherne@linux.ibm.com,
farman@linux.ibm.com, jchrist@linux.ibm.com, gor@linux.ibm.com,
hca@linux.ibm.com, freude@linux.ibm.com, rodrigo.vivi@intel.com,
intel-gvt-dev@lists.freedesktop.org, akrowiak@linux.ibm.com,
cohuck@redhat.com, oberpar@linux.ibm.com, svens@linux.ibm.com
Subject: Re: [Intel-gfx] [RFT][PATCH v1 5/6] vfio/ccw: Add kmap_local_page() for memcpy
Date: Fri, 17 Jun 2022 01:44:30 -0700 [thread overview]
Message-ID: <Yqw+7gM3Lz96UFdz@infradead.org> (raw)
In-Reply-To: <20220616235212.15185-6-nicolinc@nvidia.com>
On Thu, Jun 16, 2022 at 04:52:11PM -0700, Nicolin Chen wrote:
> The pinned PFN list returned from vfio_pin_pages() is simply converted
> using page_to_pfn() without protection, so direct access via memcpy()
> will crash on S390 if the PFN is an IO PFN. Instead, the pages should
> be touched using kmap_local_page().
I don't see how this helps. kmap_local_page only works for either
pages in the kernel direct map or highmem, but not for memory that needs
to be ioremapped. And there is no highmem on s390.
next prev parent reply other threads:[~2022-06-17 8:44 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-16 23:52 [RFT][PATCH v1 0/6] Update vfio_pin/unpin_pages API Nicolin Chen
2022-06-16 23:52 ` Nicolin Chen
2022-06-16 23:52 ` [RFT][PATCH v1 1/6] vfio/ap: Pass in physical address of ind to ap_aqic() Nicolin Chen
2022-06-16 23:52 ` Nicolin Chen
2022-06-20 10:00 ` Harald Freudenberger
2022-06-20 10:00 ` Harald Freudenberger
2022-06-21 21:01 ` Nicolin Chen
2022-06-21 21:01 ` [Intel-gfx] " Nicolin Chen
2022-06-21 21:01 ` Nicolin Chen
2022-06-16 23:52 ` [RFT][PATCH v1 2/6] vfio/ccw: Only pass in contiguous pages Nicolin Chen
2022-06-16 23:52 ` Nicolin Chen
2022-06-16 23:52 ` [RFT][PATCH v1 3/6] vfio: Pass in starting IOVA to vfio_pin/unpin_pages API Nicolin Chen
2022-06-16 23:52 ` Nicolin Chen
2022-06-17 8:42 ` Christoph Hellwig
2022-06-17 8:42 ` [Intel-gfx] " Christoph Hellwig
2022-06-17 21:57 ` Nicolin Chen
2022-06-17 21:57 ` Nicolin Chen
2022-06-22 1:18 ` Nicolin Chen
2022-06-22 1:18 ` [Intel-gfx] " Nicolin Chen
2022-06-22 1:18 ` Nicolin Chen
2022-06-16 23:52 ` [RFT][PATCH v1 4/6] vfio: Rename user_iova of vfio_dma_rw() Nicolin Chen
2022-06-16 23:52 ` Nicolin Chen
2022-06-16 23:52 ` [RFT][PATCH v1 5/6] vfio/ccw: Add kmap_local_page() for memcpy Nicolin Chen
2022-06-16 23:52 ` Nicolin Chen
2022-06-17 8:44 ` Christoph Hellwig [this message]
2022-06-17 8:44 ` [Intel-gfx] " Christoph Hellwig
2022-06-17 21:58 ` Nicolin Chen
2022-06-17 21:58 ` Nicolin Chen
2022-06-20 2:57 ` Jason Gunthorpe
2022-06-20 2:57 ` [Intel-gfx] " Jason Gunthorpe
2022-06-20 2:57 ` Jason Gunthorpe
2022-06-20 6:32 ` Christoph Hellwig
2022-06-20 6:32 ` [Intel-gfx] " Christoph Hellwig
2022-06-20 15:39 ` Jason Gunthorpe
2022-06-20 15:39 ` [Intel-gfx] " Jason Gunthorpe
2022-06-20 15:39 ` Jason Gunthorpe
2022-06-21 21:21 ` Nicolin Chen
2022-06-21 21:21 ` [Intel-gfx] " Nicolin Chen
2022-06-21 21:21 ` Nicolin Chen
2022-06-24 13:56 ` Jason Gunthorpe
2022-06-24 13:56 ` [Intel-gfx] " Jason Gunthorpe
2022-06-24 13:56 ` Jason Gunthorpe
2022-06-24 19:22 ` Nicolin Chen
2022-06-24 19:22 ` Nicolin Chen
2022-06-24 19:30 ` Jason Gunthorpe
2022-06-24 19:30 ` [Intel-gfx] " Jason Gunthorpe
2022-06-24 19:30 ` Jason Gunthorpe
2022-06-24 20:12 ` Nicolin Chen
2022-06-24 20:12 ` Nicolin Chen
2022-06-24 22:42 ` Jason Gunthorpe
2022-06-24 22:42 ` [Intel-gfx] " Jason Gunthorpe
2022-06-24 22:42 ` Jason Gunthorpe
2022-06-16 23:52 ` [RFT][PATCH v1 6/6] vfio: Replace phys_pfn with phys_page for vfio_pin_pages() Nicolin Chen
2022-06-16 23:52 ` Nicolin Chen
2022-06-17 8:54 ` Christoph Hellwig
2022-06-17 8:54 ` [Intel-gfx] " Christoph Hellwig
2022-06-17 22:06 ` Nicolin Chen
2022-06-17 22:06 ` Nicolin Chen
2022-06-19 6:18 ` Christoph Hellwig
2022-06-19 6:18 ` [Intel-gfx] " Christoph Hellwig
2022-06-19 6:41 ` Nicolin Chen
2022-06-19 6:41 ` Nicolin Chen
2022-06-20 3:00 ` Jason Gunthorpe
2022-06-20 3:00 ` [Intel-gfx] " Jason Gunthorpe
2022-06-20 3:00 ` Jason Gunthorpe
2022-06-20 5:51 ` Christoph Hellwig
2022-06-20 5:51 ` [Intel-gfx] " Christoph Hellwig
2022-06-20 6:37 ` Christoph Hellwig
2022-06-20 6:37 ` [Intel-gfx] " Christoph Hellwig
2022-06-20 15:36 ` Jason Gunthorpe
2022-06-20 15:36 ` [Intel-gfx] " Jason Gunthorpe
2022-06-20 15:36 ` Jason Gunthorpe
2022-06-21 21:47 ` Nicolin Chen
2022-06-21 21:47 ` [Intel-gfx] " Nicolin Chen
2022-06-21 21:47 ` Nicolin Chen
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