<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/drivers/hv, branch dev-5.15-intel</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.15-intel</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.15-intel'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/'/>
<updated>2022-04-20T07:34:16+00:00</updated>
<entry>
<title>Drivers: hv: balloon: Disable balloon and hot-add accordingly</title>
<updated>2022-04-20T07:34:16+00:00</updated>
<author>
<name>Boqun Feng</name>
<email>boqun.feng@gmail.com</email>
</author>
<published>2022-03-25T02:32:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=c3f86aef97cf2671d65ce67f02190efc2adc71ae'/>
<id>urn:sha1:c3f86aef97cf2671d65ce67f02190efc2adc71ae</id>
<content type='text'>
[ Upstream commit be5802795cf8d0b881745fa9ba7790293b382280 ]

Currently there are known potential issues for balloon and hot-add on
ARM64:

*	Unballoon requests from Hyper-V should only unballoon ranges
	that are guest page size aligned, otherwise guests cannot handle
	because it's impossible to partially free a page. This is a
	problem when guest page size &gt; 4096 bytes.

*	Memory hot-add requests from Hyper-V should provide the NUMA
	node id of the added ranges or ARM64 should have a functional
	memory_add_physaddr_to_nid(), otherwise the node id is missing
	for add_memory().

These issues require discussions on design and implementation. In the
meanwhile, post_status() is working and essential to guest monitoring.
Therefore instead of disabling the entire hv_balloon driver, the
ballooning (when page size &gt; 4096 bytes) and hot-add are disabled
accordingly for now. Once the issues are fixed, they can be re-enable in
these cases.

Signed-off-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/20220325023212.1570049-3-boqun.feng@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Prevent load re-ordering when reading ring buffer</title>
<updated>2022-04-20T07:34:15+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mikelley@microsoft.com</email>
</author>
<published>2022-03-27T15:25:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=44f95a5aae99afff298491c057acae4d895c9bdd'/>
<id>urn:sha1:44f95a5aae99afff298491c057acae4d895c9bdd</id>
<content type='text'>
[ Upstream commit b6cae15b5710c8097aad26a2e5e752c323ee5348 ]

When reading a packet from a host-to-guest ring buffer, there is no
memory barrier between reading the write index (to see if there is
a packet to read) and reading the contents of the packet. The Hyper-V
host uses store-release when updating the write index to ensure that
writes of the packet data are completed first. On the guest side,
the processor can reorder and read the packet data before the write
index, and sometimes get stale packet data. Getting such stale packet
data has been observed in a reproducible case in a VM on ARM64.

Fix this by using virt_load_acquire() to read the write index,
ensuring that reads of the packet data cannot be reordered
before it. Preventing such reordering is logically correct, and
with this change, getting stale data can no longer be reproduced.

Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Andrea Parri (Microsoft) &lt;parri.andrea@gmail.com&gt;
Link: https://lore.kernel.org/r/1648394710-33480-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Deactivate sysctl_record_panic_msg by default in isolated guests</title>
<updated>2022-04-20T07:34:15+00:00</updated>
<author>
<name>Andrea Parri (Microsoft)</name>
<email>parri.andrea@gmail.com</email>
</author>
<published>2022-03-01T14:11:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=1b576e81d31b56b248316b8ff816b1cc5c4407c7'/>
<id>urn:sha1:1b576e81d31b56b248316b8ff816b1cc5c4407c7</id>
<content type='text'>
[ Upstream commit 9f8b577f7b43b2170628d6c537252785dcc2dcea ]

hv_panic_page might contain guest-sensitive information, do not dump it
over to Hyper-V by default in isolated guests.

While at it, update some comments in hyperv_{panic,die}_event().

Reported-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Signed-off-by: Andrea Parri (Microsoft) &lt;parri.andrea@gmail.com&gt;
Reviewed-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Link: https://lore.kernel.org/r/20220301141135.2232-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb()</title>
<updated>2022-04-13T18:59:27+00:00</updated>
<author>
<name>Andrea Parri (Microsoft)</name>
<email>parri.andrea@gmail.com</email>
</author>
<published>2022-03-28T15:44:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=469eed08becdd16368277855d78095622db80513'/>
<id>urn:sha1:469eed08becdd16368277855d78095622db80513</id>
<content type='text'>
commit eaa03d34535872d29004cb5cf77dc9dec1ba9a25 upstream.

Following the recommendation in Documentation/memory-barriers.txt for
virtual machine guests.

Fixes: 8b6a877c060ed ("Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels")
Signed-off-by: Andrea Parri (Microsoft) &lt;parri.andrea@gmail.com&gt;
Link: https://lore.kernel.org/r/20220328154457.100872-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Fix potential crash on module unload</title>
<updated>2022-04-13T18:59:14+00:00</updated>
<author>
<name>Guilherme G. Piccoli</name>
<email>gpiccoli@igalia.com</email>
</author>
<published>2022-03-15T20:35:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=dcd6b1a624c0ffa21034d8b1e02e9d068458f596'/>
<id>urn:sha1:dcd6b1a624c0ffa21034d8b1e02e9d068458f596</id>
<content type='text'>
[ Upstream commit 792f232d57ff28bbd5f9c4abe0466b23d5879dc8 ]

The vmbus driver relies on the panic notifier infrastructure to perform
some operations when a panic event is detected. Since vmbus can be built
as module, it is required that the driver handles both registering and
unregistering such panic notifier callback.

After commit 74347a99e73a ("x86/Hyper-V: Unload vmbus channel in hv panic callback")
though, the panic notifier registration is done unconditionally in the module
initialization routine whereas the unregistering procedure is conditionally
guarded and executes only if HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE capability
is set.

This patch fixes that by unconditionally unregistering the panic notifier
in the module's exit routine as well.

Fixes: 74347a99e73a ("x86/Hyper-V: Unload vmbus channel in hv panic callback")
Signed-off-by: Guilherme G. Piccoli &lt;gpiccoli@igalia.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/20220315203535.682306-1-gpiccoli@igalia.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>hv_balloon: rate-limit "Unhandled message" warning</title>
<updated>2022-04-08T12:23:37+00:00</updated>
<author>
<name>Anssi Hannula</name>
<email>anssi.hannula@bitwise.fi</email>
</author>
<published>2022-02-22T14:14:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=383798d13aea474de27fd998fbf6f15b891cc8f6'/>
<id>urn:sha1:383798d13aea474de27fd998fbf6f15b891cc8f6</id>
<content type='text'>
[ Upstream commit 1d7286729aa616772be334eb908e11f527e1e291 ]

For a couple of times I have encountered a situation where

  hv_balloon: Unhandled message: type: 12447

is being flooded over 1 million times per second with various values,
filling the log and consuming cycles, making debugging difficult.

Add rate limiting to the message.

Most other Hyper-V drivers already have similar rate limiting in their
message callbacks.

The cause of the floods in my case was probably fixed by 96d9d1fa5cd5
("Drivers: hv: balloon: account for vmbus packet header in
max_pkt_size").

Fixes: 9aa8b50b2b3d ("Drivers: hv: Add Hyper-V balloon driver")
Signed-off-by: Anssi Hannula &lt;anssi.hannula@bitwise.fi&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/20220222141400.98160-1-anssi.hannula@bitwise.fi
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>hv: utils: add PTP_1588_CLOCK to Kconfig to fix build</title>
<updated>2022-04-08T12:22:46+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2021-11-26T02:33:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=d5aad7d63b1b5c1f3c4b69e12c05e7c7d196fae8'/>
<id>urn:sha1:d5aad7d63b1b5c1f3c4b69e12c05e7c7d196fae8</id>
<content type='text'>
commit 1dc2f2b81a6a9895da59f3915760f6c0c3074492 upstream.

The hyperv utilities use PTP clock interfaces and should depend a
a kconfig symbol such that they will be built as a loadable module or
builtin so that linker errors do not happen.

Prevents these build errors:

ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit':
hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister'
ld: drivers/hv/hv_util.o: in function `hv_timesync_init':
hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register'

Fixes: 3716a49a81ba ("hv_utils: implement Hyper-V PTP source")
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: "K. Y. Srinivasan" &lt;kys@microsoft.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: Wei Liu &lt;wei.liu@kernel.org&gt;
Cc: Dexuan Cui &lt;decui@microsoft.com&gt;
Cc: linux-hyperv@vger.kernel.org
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/20211126023316.25184-1-rdunlap@infradead.org
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Cc: Petr Štetiar &lt;ynezz@true.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: vmbus: Fix memory leak in vmbus_add_channel_kobj</title>
<updated>2022-02-23T11:03:16+00:00</updated>
<author>
<name>Miaoqian Lin</name>
<email>linmq006@gmail.com</email>
</author>
<published>2022-02-03T17:30:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=c377e2ba78d3fe9a1f0b4ec424e75f81da7e81e9'/>
<id>urn:sha1:c377e2ba78d3fe9a1f0b4ec424e75f81da7e81e9</id>
<content type='text'>
[ Upstream commit 8bc69f86328e87a0ffa79438430cc82f3aa6a194 ]

kobject_init_and_add() takes reference even when it fails.
According to the doc of kobject_init_and_add()：

   If this function returns an error, kobject_put() must be called to
   properly clean up the memory associated with the object.

Fix memory leak by calling kobject_put().

Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info")
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Reviewed-by: Juan Vazquez &lt;juvazq@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20220203173008.43480-1-linmq006@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: balloon: account for vmbus packet header in max_pkt_size</title>
<updated>2022-02-01T16:27:11+00:00</updated>
<author>
<name>Yanming Liu</name>
<email>yanminglr@gmail.com</email>
</author>
<published>2022-01-19T20:20:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=da20522eba44f6bdf72f755519246c30b8d172ac'/>
<id>urn:sha1:da20522eba44f6bdf72f755519246c30b8d172ac</id>
<content type='text'>
[ Upstream commit 96d9d1fa5cd505078534113308ced0aa56d8da58 ]

Commit adae1e931acd ("Drivers: hv: vmbus: Copy packets sent by Hyper-V
out of the ring buffer") introduced a notion of maximum packet size in
vmbus channel and used that size to initialize a buffer holding all
incoming packet along with their vmbus packet header. hv_balloon uses
the default maximum packet size VMBUS_DEFAULT_MAX_PKT_SIZE which matches
its maximum message size, however vmbus_open expects this size to also
include vmbus packet header. This leads to 4096 bytes
dm_unballoon_request messages being truncated to 4080 bytes. When the
driver tries to read next packet it starts from a wrong read_index,
receives garbage and prints a lot of "Unhandled message: type:
&lt;garbage&gt;" in dmesg.

Allocate the buffer with HV_HYP_PAGE_SIZE more bytes to make room for
the header.

Fixes: adae1e931acd ("Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer")
Suggested-by: Michael Kelley (LINUX) &lt;mikelley@microsoft.com&gt;
Suggested-by: Andrea Parri (Microsoft) &lt;parri.andrea@gmail.com&gt;
Signed-off-by: Yanming Liu &lt;yanminglr@gmail.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Andrea Parri (Microsoft) &lt;parri.andrea@gmail.com&gt;
Link: https://lore.kernel.org/r/20220119202052.3006981-1-yanminglr@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Drivers: hv: balloon: Use VMBUS_RING_SIZE() wrapper for dm_ring_size</title>
<updated>2021-11-25T08:48:46+00:00</updated>
<author>
<name>Boqun Feng</name>
<email>boqun.feng@gmail.com</email>
</author>
<published>2021-11-01T15:00:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=cd198aea9e8dc1a16a40ed52a6a4d42be470c151'/>
<id>urn:sha1:cd198aea9e8dc1a16a40ed52a6a4d42be470c151</id>
<content type='text'>
commit 8a7eb2d476c6823cd44d8c25a6230a52417d7ef8 upstream.

Baihua reported an error when boot an ARM64 guest with PAGE_SIZE=64k and
BALLOON is enabled:

	hv_vmbus: registering driver hv_balloon
	hv_vmbus: probe failed for device 1eccfd72-4b41-45ef-b73a-4a6e44c12924 (-22)

The cause of this is that the ringbuffer size for hv_balloon is not
adjusted with VMBUS_RING_SIZE(), which makes the size not large enough
for ringbuffers on guest with PAGE_SIZE=64k. Therefore use
VMBUS_RING_SIZE() to calculate the ringbuffer size. Note that the old
size (20 * 1024) counts a 4k header in the total size, while
VMBUS_RING_SIZE() expects the parameter as the payload size, so use
16 * 1024.

Cc: &lt;stable@vger.kernel.org&gt; # 5.15.x
Reported-by: Baihua Lu &lt;baihua.lu@microsoft.com&gt;
Signed-off-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Tested-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Link: https://lore.kernel.org/r/20211101150026.736124-1-boqun.feng@gmail.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
