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From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: David Hildenbrand <david@redhat.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Dan Williams <dan.j.williams@intel.com>,
	Hanjun Guo <guohanjun@huawei.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	virtualization@lists.linux-foundation.org, linux-mm@kvack.org
Subject: [PATCH v3 0/3] virtio-mem: disallow mapping virtio-mem memory via /dev/mem
Date: Tue, 31 Aug 2021 22:21:38 +0200	[thread overview]
Message-ID: <20210831202141.13846-1-david@redhat.com> (raw)

I think this might be a good fit for the -mm tree, as the actual virtio-mem
changes are rather small.

--

Let's add the basic infrastructure to exclude some physical memory
regions marked as "IORESOURCE_SYSTEM_RAM" completely from /dev/mem access,
even though they are not marked IORESOURCE_BUSY and even though
"iomem=relaxed" is set. Resource IORESOURCE_EXCLUSIVE for that purpose
instead of adding new flags to express something similar to
"soft-busy" or "not busy yet, but already prepared by a driver and not
to be mapped by user space".

Use it for virtio-mem, to disallow mapping any virtio-mem memory via
/dev/mem to user space after the virtio-mem driver was loaded.

Details can be found in patch #2 and #3.

v2 -> v3:
- "kernel/resource: clean up and optimize iomem_is_exclusive()"
-- Reshuffled and moved for_each_resource() etc. into this patch
- "kernel/resource: disallow access to exclusive system RAM regions"
-- Leave CONFIG_STRICT_DEVMEM=n alone. Hoog into iomem_is_exclusive()
   instead.
-- Improve comments
- "virtio-mem: disallow mapping virtio-mem memory via /dev/mem"
-- Don't allow building virtio_mem without CONFIG_STRICT_DEVMEM when we
   have CONFIG_DEVMEM, where we don't have any guarantees.
- Rework all patch descriptions

v1 -> v2:
- "/dev/mem: disallow access to explicitly excluded system RAM regions"
-- Introduce and use for_each_resource() and next_resource_skip_children()
-- s/iomem_range_contains_excluded/iomem_range_contains_excluded_devmem/
- "kernel/resource: cleanup and optimize iomem_is_exclusive()"
-- Use for_each_resource()

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: virtualization@lists.linux-foundation.org
Cc: linux-mm@kvack.org

David Hildenbrand (3):
  kernel/resource: clean up and optimize iomem_is_exclusive()
  kernel/resource: disallow access to exclusive system RAM regions
  virtio-mem: disallow mapping virtio-mem memory via /dev/mem

 drivers/virtio/Kconfig      |  1 +
 drivers/virtio/virtio_mem.c |  4 ++-
 kernel/resource.c           | 54 ++++++++++++++++++++++++++-----------
 3 files changed, 43 insertions(+), 16 deletions(-)


base-commit: 7d2a07b769330c34b4deabeed939325c77a7ec2f
-- 
2.31.1


             reply	other threads:[~2021-08-31 20:22 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31 20:21 David Hildenbrand [this message]
2021-08-31 20:21 ` [PATCH v3 1/3] kernel/resource: clean up and optimize iomem_is_exclusive() David Hildenbrand
2021-09-01 19:43   ` Williams, Dan J
2021-09-02  7:52     ` David Hildenbrand
2021-09-02 15:54       ` Dan Williams
2021-08-31 20:21 ` [PATCH v3 2/3] kernel/resource: disallow access to exclusive system RAM regions David Hildenbrand
2021-09-01 19:37   ` Williams, Dan J
2021-08-31 20:21 ` [PATCH v3 3/3] virtio-mem: disallow mapping virtio-mem memory via /dev/mem David Hildenbrand
2021-09-01 19:39   ` Williams, Dan J

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