linux-stable.git/drivers/hv, branch linux-3.14.y Linux kernel stable tree Drivers: hv: vmbus: prevent cpu offlining on newer hypervisors 2016-05-04T21:51:25+00:00 Vitaly Kuznetsov vkuznets@redhat.com 2015-02-27T19:25:51+00:00 f7aecad1b5338e309496c2604e48b0e418b08c7c commit e513229b4c386e6c9f66298c13fde92f73e6e1ac upstream. When an SMP Hyper-V guest is running on top of 2012R2 Server and secondary cpus are sent offline (with echo 0 > /sys/devices/system/cpu/cpu$cpu/online) the system freeze is observed. This happens due to the fact that on newer hypervisors (Win8, WS2012R2, ...) vmbus channel handlers are distributed across all cpus (see init_vp_index() function in drivers/hv/channel_mgmt.c) and on cpu offlining nobody reassigns them to CPU0. Prevent cpu offlining when vmbus is loaded until the issue is fixed host-side. This patch also disables hibernation but it is OK as it is also broken (MCE error is hit on resume). Suspend still works. Tested with WS2008R2 and WS2012R2. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> [ 3chas3@gmail.com: rebase to 3.14-stable ] Signed-off-by: Chas Williams <3chas3@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e513229b4c386e6c9f66298c13fde92f73e6e1ac upstream.

When an SMP Hyper-V guest is running on top of 2012R2 Server and secondary
cpus are sent offline (with echo 0 > /sys/devices/system/cpu/cpu$cpu/online)
the system freeze is observed. This happens due to the fact that on newer
hypervisors (Win8, WS2012R2, ...) vmbus channel handlers are distributed
across all cpus (see init_vp_index() function in drivers/hv/channel_mgmt.c)
and on cpu offlining nobody reassigns them to CPU0. Prevent cpu offlining
when vmbus is loaded until the issue is fixed host-side.

This patch also disables hibernation but it is OK as it is also broken (MCE
error is hit on resume). Suspend still works.

Tested with WS2008R2 and WS2012R2.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
[ 3chas3@gmail.com: rebase to 3.14-stable ]
Signed-off-by: Chas Williams <3chas3@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Don't wait after requesting offers 2015-05-13T12:17:00+00:00 K. Y. Srinivasan kys@microsoft.com 2015-03-19T15:11:34+00:00 172e21ae50f66ad75c5219d3c9daf5642fc72c86 commit 73cffdb65e679b98893f484063462c045adcf212 upstream. Don't wait after sending request for offers to the host. This wait is unnecessary and simply adds 5 seconds to the boot time. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 73cffdb65e679b98893f484063462c045adcf212 upstream.

Don't wait after sending request for offers to the host. This wait is
unnecessary and simply adds 5 seconds to the boot time.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Fix a bug in the error path in vmbus_open() 2015-05-06T19:59:19+00:00 K. Y. Srinivasan kys@microsoft.com 2015-02-27T19:26:04+00:00 25a1da2431d1f885752b3c88365c30e089affad9 commit 40384e4bbeb9f2651fe9bffc0062d9f31ef625bf upstream. Correctly rollback state if the failure occurs after we have handed over the ownership of the buffer to the host. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 40384e4bbeb9f2651fe9bffc0062d9f31ef625bf upstream.

Correctly rollback state if the failure occurs after we have handed over
the ownership of the buffer to the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Fix a race condition when unregistering a device 2015-01-16T14:59:32+00:00 Vitaly Kuznetsov vkuznets@redhat.com 2014-11-04T12:40:11+00:00 8a8c38c8e681f36170d6d565c8c50539f7845667 commit 04a258c162a85c0f4ae56be67634dc43c9a4fa9b upstream. When build with Debug the following crash is sometimes observed: Call Trace: [<ffffffff812b9600>] string+0x40/0x100 [<ffffffff812bb038>] vsnprintf+0x218/0x5e0 [<ffffffff810baf7d>] ? trace_hardirqs_off+0xd/0x10 [<ffffffff812bb4c1>] vscnprintf+0x11/0x30 [<ffffffff8107a2f0>] vprintk+0xd0/0x5c0 [<ffffffffa0051ea0>] ? vmbus_process_rescind_offer+0x0/0x110 [hv_vmbus] [<ffffffff8155c71c>] printk+0x41/0x45 [<ffffffffa004ebac>] vmbus_device_unregister+0x2c/0x40 [hv_vmbus] [<ffffffffa0051ecb>] vmbus_process_rescind_offer+0x2b/0x110 [hv_vmbus] ... This happens due to the following race: between 'if (channel->device_obj)' check in vmbus_process_rescind_offer() and pr_debug() in vmbus_device_unregister() the device can disappear. Fix the issue by taking an additional reference to the device before proceeding to vmbus_device_unregister(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 04a258c162a85c0f4ae56be67634dc43c9a4fa9b upstream.

When build with Debug the following crash is sometimes observed:
Call Trace:
 [<ffffffff812b9600>] string+0x40/0x100
 [<ffffffff812bb038>] vsnprintf+0x218/0x5e0
 [<ffffffff810baf7d>] ? trace_hardirqs_off+0xd/0x10
 [<ffffffff812bb4c1>] vscnprintf+0x11/0x30
 [<ffffffff8107a2f0>] vprintk+0xd0/0x5c0
 [<ffffffffa0051ea0>] ? vmbus_process_rescind_offer+0x0/0x110 [hv_vmbus]
 [<ffffffff8155c71c>] printk+0x41/0x45
 [<ffffffffa004ebac>] vmbus_device_unregister+0x2c/0x40 [hv_vmbus]
 [<ffffffffa0051ecb>] vmbus_process_rescind_offer+0x2b/0x110 [hv_vmbus]
...

This happens due to the following race: between 'if (channel->device_obj)' check
in vmbus_process_rescind_offer() and pr_debug() in vmbus_device_unregister() the
device can disappear. Fix the issue by taking an additional reference to the
device before proceeding to vmbus_device_unregister().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Fix a bug in vmbus_open() 2014-10-30T16:38:21+00:00 K. Y. Srinivasan kys@microsoft.com 2014-08-27T23:25:35+00:00 4b417357687ddf1191c248fc18c167822c4d978b commit 45d727cee9e200f5b351528b9fb063b69cf702c8 upstream. Fix a bug in vmbus_open() and properly propagate the error. I would like to thank Dexuan Cui <decui@microsoft.com> for identifying the issue. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 45d727cee9e200f5b351528b9fb063b69cf702c8 upstream.

Fix a bug in vmbus_open() and properly propagate the error. I would
like to thank Dexuan Cui <decui@microsoft.com> for identifying the
issue.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Cleanup vmbus_establish_gpadl() 2014-10-30T16:38:21+00:00 K. Y. Srinivasan kys@microsoft.com 2014-08-27T23:25:34+00:00 9c9520596f2c96b906712c468d776319d7836540 commit 72c6b71c245dac8f371167d97ef471b367d0b66b upstream. Eliminate the call to BUG_ON() by waiting for the host to respond. We are trying to reclaim the ownership of memory that was given to the host and so we will have to wait until the host responds. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 72c6b71c245dac8f371167d97ef471b367d0b66b upstream.

Eliminate the call to BUG_ON() by waiting for the host to respond. We are
trying to reclaim the ownership of memory that was given to the host and so
we will have to wait until the host responds.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Cleanup vmbus_close_internal() 2014-10-30T16:38:21+00:00 K. Y. Srinivasan kys@microsoft.com 2014-08-27T23:25:33+00:00 965d61bf8737f52ffd60b98255eb6d07b6ea2b62 commit 98d731bb064a9d1817a6ca9bf8b97051334a7cfe upstream. Eliminate calls to BUG_ON() in vmbus_close_internal(). We have chosen to potentially leak memory, than crash the guest in case of failures. In this version of the patch I have addressed comments from Dan Carpenter (dan.carpenter@oracle.com). Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 98d731bb064a9d1817a6ca9bf8b97051334a7cfe upstream.

Eliminate calls to BUG_ON() in vmbus_close_internal().
We have chosen to potentially leak memory, than crash the guest
in case of failures.

In this version of the patch I have addressed comments from
Dan Carpenter (dan.carpenter@oracle.com).

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Cleanup vmbus_teardown_gpadl() 2014-10-30T16:38:21+00:00 K. Y. Srinivasan kys@microsoft.com 2014-08-27T23:25:32+00:00 b8c396a6c072ddbdd31540d61bd24a12445e33a0 commit 66be653083057358724d56d817e870e53fb81ca7 upstream. Eliminate calls to BUG_ON() by properly handling errors. In cases where rollback is possible, we will return the appropriate error to have the calling code decide how to rollback state. In the case where we are transferring ownership of the guest physical pages to the host, we will wait for the host to respond. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 66be653083057358724d56d817e870e53fb81ca7 upstream.

Eliminate calls to BUG_ON() by properly handling errors. In cases where
rollback is possible, we will return the appropriate error to have the
calling code decide how to rollback state. In the case where we are
transferring ownership of the guest physical pages to the host,
we will wait for the host to respond.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: vmbus: Cleanup vmbus_post_msg() 2014-10-30T16:38:21+00:00 K. Y. Srinivasan kys@microsoft.com 2014-08-27T23:25:31+00:00 5fe80abd8a4fd879a6bf02e3936f03dbffc57c41 commit fdeebcc62279119dbeafbc1a2e39e773839025fd upstream. Posting messages to the host can fail because of transient resource related failures. Correctly deal with these failures and increase the number of attempts to post the message before giving up. In this version of the patch, I have normalized the error code to Linux error code. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fdeebcc62279119dbeafbc1a2e39e773839025fd upstream.

Posting messages to the host can fail because of transient resource
related failures. Correctly deal with these failures and increase the
number of attempts to post the message before giving up.

In this version of the patch, I have normalized the error code to
Linux error code.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers: hv: util: Fix a bug in the KVP code 2014-07-28T15:05:56+00:00 K. Y. Srinivasan kys@microsoft.com 2014-07-07T23:34:25+00:00 d887a032c8d56b4b525f698ac2354876f6a4a5b4 commit 9bd2d0dfe4714dd5d7c09a93a5c9ea9e14ceb3fc upstream. Add code to poll the channel since we process only one message at a time and the host may not interrupt us. Also increase the receive buffer size since some KVP messages are close to 8K bytes in size. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9bd2d0dfe4714dd5d7c09a93a5c9ea9e14ceb3fc upstream.

Add code to poll the channel since we process only one message
at a time and the host may not interrupt us. Also increase the
receive buffer size since some KVP messages are close to 8K bytes in size.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>