linux-stable.git/drivers/hv, branch v5.4.166

hyperv/vmbus: include linux/bitops.h

2021-11-17T08:48:20+00:00

[ Upstream commit 8017c99680fa65e1e8d999df1583de476a187830 ]

On arm64 randconfig builds, hyperv sometimes fails with this
error:

In file included from drivers/hv/hv_trace.c:3:
In file included from drivers/hv/hyperv_vmbus.h:16:
In file included from arch/arm64/include/asm/sync_bitops.h:5:
arch/arm64/include/asm/bitops.h:11:2: error: only  can be included directly
In file included from include/asm-generic/bitops/hweight.h:5:
include/asm-generic/bitops/arch_hweight.h:9:9: error: implicit declaration of function '__sw_hweight32' [-Werror,-Wimplicit-function-declaration]
include/asm-generic/bitops/atomic.h:17:7: error: implicit declaration of function 'BIT_WORD' [-Werror,-Wimplicit-function-declaration]

Include the correct header first.

Signed-off-by: Arnd Bergmann 
Link: https://lore.kernel.org/r/20211018131929.2260087-1-arnd@kernel.org
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

hv_utils: Fix passing zero to 'PTR_ERR' warning

2021-07-14T14:53:16+00:00

[ Upstream commit c6a8625fa4c6b0a97860d053271660ccedc3d1b3 ]

Sparse warn this:

drivers/hv/hv_util.c:753 hv_timesync_init() warn:
 passing zero to 'PTR_ERR'

Use PTR_ERR_OR_ZERO instead of PTR_ERR to fix this.

Signed-off-by: YueHaibing 
Link: https://lore.kernel.org/r/20210514070116.16800-1-yuehaibing@huawei.com
[ wei: change %ld to %d ]
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Increase wait time for VMbus unload

2021-05-14T07:44:22+00:00

[ Upstream commit 77db0ec8b7764cb9b09b78066ebfd47b2c0c1909 ]

When running in Azure, disks may be connected to a Linux VM with
read/write caching enabled. If a VM panics and issues a VMbus
UNLOAD request to Hyper-V, the response is delayed until all dirty
data in the disk cache is flushed.  In extreme cases, this flushing
can take 10's of seconds, depending on the disk speed and the amount
of dirty data. If kdump is configured for the VM, the current 10 second
timeout in vmbus_wait_for_unload() may be exceeded, and the UNLOAD
complete message may arrive well after the kdump kernel is already
running, causing problems.  Note that no problem occurs if kdump is
not enabled because Hyper-V waits for the cache flush before doing
a reboot through the BIOS/UEFI code.

Fix this problem by increasing the timeout in vmbus_wait_for_unload()
to 100 seconds. Also output periodic messages so that if anyone is
watching the serial console, they won't think the VM is completely
hung.

Fixes: 911e1987efc8 ("Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload")
Signed-off-by: Michael Kelley 
Reviewed-by: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/1618894089-126662-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()

2021-03-04T09:26:24+00:00

[ Upstream commit e3fa4b747f085d2cda09bba0533b86fa76038635 ]

When channel->device_obj is non-NULL, vmbus_onoffer_rescind() could
invoke put_device(), that will eventually release the device and free
the channel object (cf. vmbus_device_release()).  However, a pointer
to the object is dereferenced again later to load the primary_channel.
The use-after-free can be avoided by noticing that this load/check is
redundant if device_obj is non-NULL: primary_channel must be NULL if
device_obj is non-NULL, cf. vmbus_add_channel_work().

Fixes: 54a66265d6754b ("Drivers: hv: vmbus: Fix rescind handling")
Reported-by: Juan Vazquez 
Signed-off-by: Andrea Parri (Microsoft) 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20201209070827.29335-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Allow cleanup of VMBUS_CONNECT_CPU if disconnected

2020-11-24T12:29:23+00:00

commit 92e4dc8b05663d6539b1b8375f3b1cf7b204cfe9 upstream.

When invoking kexec() on a Linux guest running on a Hyper-V host, the
kernel panics.

    RIP: 0010:cpuhp_issue_call+0x137/0x140
    Call Trace:
    __cpuhp_remove_state_cpuslocked+0x99/0x100
    __cpuhp_remove_state+0x1c/0x30
    hv_kexec_handler+0x23/0x30 [hv_vmbus]
    hv_machine_shutdown+0x1e/0x30
    machine_shutdown+0x10/0x20
    kernel_kexec+0x6d/0x96
    __do_sys_reboot+0x1ef/0x230
    __x64_sys_reboot+0x1d/0x20
    do_syscall_64+0x6b/0x3d8
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

This was due to hv_synic_cleanup() callback returning -EBUSY to
cpuhp_issue_call() when tearing down the VMBUS_CONNECT_CPU, even
if the vmbus_connection.conn_state = DISCONNECTED. hv_synic_cleanup()
should succeed in the case where vmbus_connection.conn_state
is DISCONNECTED.

Fix is to add an extra condition to test for
vmbus_connection.conn_state == CONNECTED on the VMBUS_CONNECT_CPU and
only return early if true. This way the kexec() path can still shut
everything down while preserving the initial behavior of preventing
CPU offlining on the VMBUS_CONNECT_CPU while the VM is running.

Fixes: 8a857c55420f29 ("Drivers: hv: vmbus: Always handle the VMBus messages on CPU0")
Signed-off-by: Chris Co 
Reviewed-by: Andrea Parri (Microsoft) 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201110190118.15596-1-chrco@linux.microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Greg Kroah-Hartman

hv_balloon: disable warning when floor reached

2020-11-18T18:20:17+00:00

[ Upstream commit 2c3bd2a5c86fe744e8377733c5e511a5ca1e14f5 ]

It is not an error if the host requests to balloon down, but the VM
refuses to do so. Without this change a warning is logged in dmesg
every five minutes.

Fixes:  b3bb97b8a49f3 ("Drivers: hv: balloon: Add logging for dynamic memory operations")

Signed-off-by: Olaf Hering 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20201008071216.16554-1-olaf@aepfle.de
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload

2020-09-23T10:40:40+00:00

[ Upstream commit 911e1987efc8f3e6445955fbae7f54b428b92bd3 ]

vmbus_wait_for_unload() looks for a CHANNELMSG_UNLOAD_RESPONSE message
coming from Hyper-V.  But if the message isn't found for some reason,
the panic path gets hung forever.  Add a timeout of 10 seconds to prevent
this.

Fixes: 415719160de3 ("Drivers: hv: vmbus: avoid scheduling in interrupt context in vmbus_initiate_unload()")
Signed-off-by: Michael Kelley 
Reviewed-by: Dexuan Cui 
Reviewed-by: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/1600026449-23651-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()

2020-09-23T10:40:40+00:00

[ Upstream commit 19873eec7e13fda140a0ebc75d6664e57c00bfb1 ]

After we Stop and later Start a VM that uses Accelerated Networking (NIC
SR-IOV), currently the VF vmbus device's Instance GUID can change, so after
vmbus_bus_resume() -> vmbus_request_offers(), vmbus_onoffer() can not find
the original vmbus channel of the VF, and hence we can't complete()
vmbus_connection.ready_for_resume_event in check_ready_for_resume_event(),
and the VM hangs in vmbus_bus_resume() forever.

Fix the issue by adding a timeout, so the resuming can still succeed, and
the saved state is not lost, and according to my test, the user can disable
Accelerated Networking and then will be able to SSH into the VM for
further recovery. Also prevent the VM in question from suspending again.

The host will be fixed so in future the Instance GUID will stay the same
across hibernation.

Fixes: d8bd2d442bb2 ("Drivers: hv: vmbus: Resume after fixing up old primary channels")
Signed-off-by: Dexuan Cui 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20200905025555.45614-1-decui@microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23)

2020-08-11T13:33:38+00:00

[ Upstream commit ddc9d357b991838c2d975e8d7e4e9db26f37a7ff ]

When a Linux hv_sock app tries to connect to a Service GUID on which no
host app is listening, a recent host (RS3+) sends a
CHANNELMSG_TL_CONNECT_RESULT (23) message to Linux and this triggers such
a warning:

unknown msgtype=23
WARNING: CPU: 2 PID: 0 at drivers/hv/vmbus_drv.c:1031 vmbus_on_msg_dpc

Actually Linux can safely ignore the message because the Linux app's
connect() will time out in 2 seconds: see VSOCK_DEFAULT_CONNECT_TIMEOUT
and vsock_stream_connect(). We don't bother to make use of the message
because: 1) it's only supported on recent hosts; 2) a non-trivial effort
is required to use the message in Linux, but the benefit is small.

So, let's not see the warning by silently ignoring the message.

Signed-off-by: Dexuan Cui 
Reviewed-by: Michael Kelley 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Always handle the VMBus messages on CPU0

2020-06-22T07:31:00+00:00

[ Upstream commit 8a857c55420f29da4fc131adc22b12d474c48f4c ]

A Linux guest have to pick a "connect CPU" to communicate with the
Hyper-V host.  This CPU can not be taken offline because Hyper-V does
not provide a way to change that CPU assignment.

Current code sets the connect CPU to whatever CPU ends up running the
function vmbus_negotiate_version(), and this will generate problems if
that CPU is taken offine.

Establish CPU0 as the connect CPU, and add logics to prevents the
connect CPU from being taken offline.   We could pick some other CPU,
and we could pick that "other CPU" dynamically if there was a reason to
do so at some point in the future.  But for now, #defining the connect
CPU to 0 is the most straightforward and least complex solution.

While on this, add inline comments explaining "why" offer and rescind
messages should not be handled by a same serialized work queue.

Suggested-by: Dexuan Cui 
Signed-off-by: Andrea Parri (Microsoft) 
Reviewed-by: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com
Reviewed-by: Michael Kelley 
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin