For each storvsc_device, storvsc keeps track of the channel target CPUs
associated to the device (alloced_cpus) and it uses this information to
fill a "cache" (stor_chns) mapping CPU->channel according to a certain
heuristic. Update the alloced_cpus mask and the stor_chns array when a
channel of the storvsc device is re-assigned to a different CPU.
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: <linux-scsi@vger.kernel.org>
Link: https://lore.kernel.org/r/20200406001514.19876-12-parri.andrea@gmail.com
Reviewed-by; Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
[ wei: fix a small issue reported by kbuild test robot <lkp@intel.com> ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>
VMBus version 4.1 and later support the CHANNELMSG_MODIFYCHANNEL(22)
message type which can be used to request Hyper-V to change the vCPU
that a channel will interrupt.
Introduce the CHANNELMSG_MODIFYCHANNEL message type, and define the
vmbus_send_modifychannel() function to send CHANNELMSG_MODIFYCHANNEL
requests to the host via a hypercall. The function is then used to
define a sysfs "store" operation, which allows to change the (v)CPU
the channel will interrupt by using the sysfs interface. The feature
can be used for load balancing or other purposes.
One interesting catch here is that Hyper-V can *not* currently ACK
CHANNELMSG_MODIFYCHANNEL messages with the promise that (after the ACK
is sent) the channel won't send any more interrupts to the "old" CPU.
The peculiarity of the CHANNELMSG_MODIFYCHANNEL messages is problematic
if the user want to take a CPU offline, since we don't want to take a
CPU offline (and, potentially, "lose" channel interrupts on such CPU)
if the host is still processing a CHANNELMSG_MODIFYCHANNEL message
associated to that CPU.
It is worth mentioning, however, that we have been unable to observe
the above mentioned "race": in all our tests, CHANNELMSG_MODIFYCHANNEL
requests appeared *as if* they were processed synchronously by the host.
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-11-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
[ wei: fix conflict in channel_mgmt.c ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Since vmbus_chan_sched() dereferences the ring buffer pointer, we have
to make sure that the ring buffer data structures don't get freed while
such dereferencing is happening. Current code does this by sending an
IPI to the CPU that is allowed to access that ring buffer from interrupt
level, cf., vmbus_reset_channel_cb(). But with the new functionality
to allow changing the CPU that a channel will interrupt, we can't be
sure what CPU will be running the vmbus_chan_sched() function for a
particular channel, so the current IPI mechanism is infeasible.
Instead synchronize vmbus_chan_sched() and vmbus_reset_channel_cb() by
using the (newly introduced) per-channel spin lock "sched_lock". Move
the test for onchannel_callback being NULL before the "switch" control
statement in vmbus_chan_sched(), in order to not access the ring buffer
if the vmbus_reset_channel_cb() has been completed on the channel.
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-7-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When Hyper-V sends an interrupt to the guest, the guest has to figure
out which channel the interrupt is associated with. Hyper-V sets a bit
in a memory page that is shared with the guest, indicating a particular
"relid" that the interrupt is associated with. The current Linux code
then uses a set of per-CPU linked lists to map a given "relid" to a
pointer to a channel structure.
This design introduces a synchronization problem if the CPU that Hyper-V
will interrupt for a certain channel is changed. If the interrupt comes
on the "old CPU" and the channel was already moved to the per-CPU list
of the "new CPU", then the relid -> channel mapping will fail and the
interrupt is dropped. Similarly, if the interrupt comes on the new CPU
but the channel was not moved to the per-CPU list of the new CPU, then
the mapping will fail and the interrupt is dropped.
Relids are integers ranging from 0 to 2047. The mapping from relids to
channel structures can be done by setting up an array with 2048 entries,
each entry being a pointer to a channel structure (hence total size ~16K
bytes, which is not a problem). The array is global, so there are no
per-CPU linked lists to update. The array can be searched and updated
by loading from/storing to the array at the specified index. With no
per-CPU data structures, the above mentioned synchronization problem is
avoided and the relid2channel() function gets simpler.
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-4-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The offer and rescind works are currently scheduled on the so called
"connect CPU". However, this is not really needed: we can synchronize
the works by relying on the usage of the offer_in_progress counter and
of the channel_mutex mutex. This synchronization is already in place.
So, remove this unnecessary "bind to the connect CPU" constraint and
update the inline comments accordingly.
Suggested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-3-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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 <decui@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
VMBus message handlers (channel_message_table) receive a pointer to
'struct vmbus_channel_message_header' and cast it to a structure of their
choice, which is sometimes longer than the header. We, however, don't check
that the message is long enough so in case hypervisor screws up we'll be
accessing memory beyond what was allocated for temporary buffer.
Previously, we used to always allocate and copy 256 bytes from message page
to temporary buffer but this is hardly better: in case the message is
shorter than we expect we'll be trying to consume garbage as some real
data and no memory guarding technique will be able to identify an issue.
Introduce 'min_payload_len' to 'struct vmbus_channel_message_table_entry'
and check against it in vmbus_on_msg_dpc(). Note, we can't require the
exact length as new hypervisor versions may add extra fields to messages,
we only check that the message is not shorter than we expect.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104326.45361-1-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Strictly speaking, compiler is free to use something different from 'u32'
for 'enum vmbus_channel_message_type' (e.g. char) but it doesn't happen in
real life, just add a BUILD_BUG_ON() guardian.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104316.45303-1-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
vmbus_onmessage() doesn't need the header of the message, it only
uses it to get to the payload, we can pass the pointer to the
payload directly.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104154.45010-4-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When we need to pass a buffer with Hyper-V message we don't need to always
allocate 256 bytes for the message: the real message length is known from
the header. Change 'struct onmessage_work_context' to make it possible to
not over-allocate.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104154.45010-3-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Hyper-V Interrupt Message Page (SIMP) has 16 256-byte slots for
messages. Each message comes with a header (16 bytes) which specifies the
payload length (up to 240 bytes). vmbus_on_msg_dpc(), however, doesn't
look at the real message length and copies the whole slot to a temporary
buffer before passing it to message handlers. This is potentially dangerous
as hypervisor doesn't have to clean the whole slot when putting a new
message there and a message handler can get access to some data which
belongs to a previous message.
Note, this is not currently a problem because all message handlers are
in-kernel but eventually we may e.g. get this exported to userspace.
Note also, that this is not a performance critical path: messages (unlike
events) represent rare events so it doesn't really matter (from performance
point of view) if we copy too much.
Fix the issue by taking into account the real message length. The temporary
buffer allocated by vmbus_on_msg_dpc() remains fixed size for now. Also,
check that the supplied payload length is valid (<= 240 bytes).
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104154.45010-2-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When oops happens with panic_on_oops unset, the oops
thread is killed by die() and system continues to run.
In such case, guest should not report crash register
data to host since system still runs. Check panic_on_oops
and return directly in hyperv_report_panic() when the function
is called in the die() and panic_on_oops is unset. Fix it.
Fixes: 7ed4325a44 ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When sysctl_record_panic_msg is not set, the panic will
not be reported to Hyper-V via hyperv_report_panic_msg().
So the crash should be reported via hyperv_report_panic().
Fixes: 81b18bce48 ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-6-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When a guest VM panics, Hyper-V should be notified only once via the
crash synthetic MSRs. Current Linux code might write these crash MSRs
twice during a system panic:
1) hyperv_panic/die_event() calling hyperv_report_panic()
2) hv_kmsg_dump() calling hyperv_report_panic_msg()
Fix this by not calling hyperv_report_panic() if a kmsg dump has been
successfully registered. The notification will happen later via
hyperv_report_panic_msg().
Fixes: 7ed4325a44 ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-4-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
If kmsg_dump_register() fails, hv_panic_page will not be used
anywhere. So free and reset it.
Fixes: 81b18bce48 ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-3-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When kdump is not configured, a Hyper-V VM might still respond to
network traffic after a kernel panic when kernel parameter panic=0.
The panic CPU goes into an infinite loop with interrupts enabled,
and the VMbus driver interrupt handler still works because the
VMbus connection is unloaded only in the kdump path. The network
responses make the other end of the connection think the VM is
still functional even though it has panic'ed, which could affect any
failover actions that should be taken.
Fix this by unloading the VMbus connection during the panic process.
vmbus_initiate_unload() could then be called twice (e.g., by
hyperv_panic_event() and hv_crash_handler(), so reset the connection
state in vmbus_initiate_unload() to ensure the unload is done only
once.
Fixes: 81b18bce48 ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-2-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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 <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
- Hibernation support (Dexuan Cui).
- Latency testing framework (Branden Bonaby).
- Decoupling Hyper-V page size from guest page size (Himadri Pandya).
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull Hyper-V updates from Sasha Levin:
- support for new VMBus protocols (Andrea Parri)
- hibernation support (Dexuan Cui)
- latency testing framework (Branden Bonaby)
- decoupling Hyper-V page size from guest page size (Himadri Pandya)
* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (22 commits)
Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic
drivers/hv: Replace binary semaphore with mutex
drivers: iommu: hyperv: Make HYPERV_IOMMU only available on x86
HID: hyperv: Add the support of hibernation
hv_balloon: Add the support of hibernation
x86/hyperv: Implement hv_is_hibernation_supported()
Drivers: hv: balloon: Remove dependencies on guest page size
Drivers: hv: vmbus: Remove dependencies on guest page size
x86: hv: Add function to allocate zeroed page for Hyper-V
Drivers: hv: util: Specify ring buffer size using Hyper-V page size
Drivers: hv: Specify receive buffer size using Hyper-V page size
tools: hv: add vmbus testing tool
drivers: hv: vmbus: Introduce latency testing
video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver
video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host
hv_netvsc: Add the support of hibernation
hv_sock: Add the support of hibernation
video: hyperv_fb: Add the support of hibernation
scsi: storvsc: Add the support of hibernation
Drivers: hv: vmbus: Add module parameter to cap the VMBus version
...
The crash handler calls hv_synic_cleanup() to shutdown the
Hyper-V synthetic interrupt controller. But if the CPU
that calls hv_synic_cleanup() has a VMbus channel interrupt
assigned to it (which is likely the case in smaller VM sizes),
hv_synic_cleanup() returns an error and the synthetic
interrupt controller isn't shutdown. While the lack of
being shutdown hasn't caused a known problem, it still
should be fixed for highest reliability.
So directly call hv_synic_disable_regs() instead of
hv_synic_cleanup(), which ensures that the synic is always
shutdown.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
At a slight footprint cost (24 vs 32 bytes), mutexes are more optimal
than semaphores; it's also a nicer interface for mutual exclusion,
which is why they are encouraged over binary semaphores, when possible.
Replace the hyperv_mmio_lock, its semantics implies traditional lock
ownership; that is, the lock owner is the same for both lock/unlock
operations. Therefore it is safe to convert.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Hyper-V assumes page size to be 4K. This might not be the case for ARM64
architecture. Hence use hyper-v page size and page allocation function
to avoid conflicts between different host and guest page size on ARM64.
Signed-off-by: Himadri Pandya <himadri18.07@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Introduce user specified latency in the packet reception path
By exposing the test parameters as part of the debugfs channel
attributes. We will control the testing state via these attributes.
Signed-off-by: Branden Bonaby <brandonbonaby94@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The technique used to get the next VMBus version seems increasisly
clumsy as the number of VMBus versions increases. Performance is
not a concern since this is only done once during system boot; it's
just that we'll end up with more lines of code than is really needed.
As an alternative, introduce a table with the version numbers listed
in order (from the most recent to the oldest). vmbus_connect() loops
through the versions listed in the table until it gets an accepted
connection or gets to the end of the table (invalid version).
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Hyper-V has historically initialized stimer-based clockevents late in the
process of onlining a CPU because clockevents depend on stimer
interrupts. In the original Hyper-V design, stimer interrupts generate a
VMbus message, so the VMbus machinery must be running first, and VMbus
can't be initialized until relatively late. On x86/64, LAPIC timer based
clockevents are used during early initialization before VMbus and
stimer-based clockevents are ready, and again during CPU offlining after
the stimer clockevents have been shut down.
Unfortunately, this design creates problems when offlining CPUs for
hibernation or other purposes. stimer-based clockevents are shut down
relatively early in the offlining process, so clockevents_unbind_device()
must be used to fallback to the LAPIC-based clockevents for the remainder
of the offlining process. Furthermore, the late initialization and early
shutdown of stimer-based clockevents doesn't work well on ARM64 since there
is no other timer like the LAPIC to fallback to. So CPU onlining and
offlining doesn't work properly.
Fix this by recognizing that stimer Direct Mode is the normal path for
newer versions of Hyper-V on x86/64, and the only path on other
architectures. With stimer Direct Mode, stimer interrupts don't require any
VMbus machinery. stimer clockevents can be initialized and shut down
consistent with how it is done for other clockevent devices. While the old
VMbus-based stimer interrupts must still be supported for backward
compatibility on x86, that mode of operation can be treated as legacy.
So add a new Hyper-V stimer entry in the CPU hotplug state list, and use
that new state when in Direct Mode. Update the Hyper-V clocksource driver
to allocate and initialize stimer clockevents earlier during boot. Update
Hyper-V initialization and the VMbus driver to use this new design. As a
result, the LAPIC timer is no longer used during boot or CPU
onlining/offlining and clockevents_unbind_device() is not called. But
retain the old design as a legacy implementation for older versions of
Hyper-V that don't support Direct Mode.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lkml.kernel.org/r/1573607467-9456-1-git-send-email-mikelley@microsoft.com
If CONFIG_PM_SLEEP is not set, we can comment out these functions to avoid
the below warnings:
drivers/hv/vmbus_drv.c:2208:12: warning: ‘vmbus_bus_resume’ defined but not used [-Wunused-function]
drivers/hv/vmbus_drv.c:2128:12: warning: ‘vmbus_bus_suspend’ defined but not used [-Wunused-function]
drivers/hv/vmbus_drv.c:937:12: warning: ‘vmbus_resume’ defined but not used [-Wunused-function]
drivers/hv/vmbus_drv.c:918:12: warning: ‘vmbus_suspend’ defined but not used [-Wunused-function]
Fixes: 271b2224d4 ("Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernation")
Fixes: f53335e328 ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
When the host re-offers the primary channels upon resume, the host only
guarantees the Instance GUID doesn't change, so vmbus_bus_suspend()
should invalidate channel->offermsg.child_relid and figure out the
number of primary channels that need to be fixed up upon resume.
Upon resume, vmbus_onoffer() finds the old channel structs, and maps
the new offers to the old channels, and fixes up the old structs,
and finally the resume callbacks of the VSC drivers will re-open
the channels.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Before suspend, Linux must make sure all the hv_sock channels have been
properly cleaned up, because a hv_sock connection can not persist across
hibernation, and the user-space app must be properly notified of the
state change of the connection.
Before suspend, Linux also must make sure all the sub-channels have been
destroyed, i.e. the related channel structs of the sub-channels must be
properly removed, otherwise they would cause a conflict when the
sub-channels are recreated upon resume.
Add a counter to track such channels, and vmbus_bus_suspend() should wait
for the counter to drop to zero.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
hibernation. There is no better method to clean up the channels since
some of the channels may still be referenced by the userspace apps when
hibernation is triggered: in this case, with this patch, the "rescind"
fields of the channels are set, and the apps will thoroughly destroy
the channels after hibernation.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Before Linux enters hibernation, it sends the CHANNELMSG_UNLOAD message to
the host so all the offers are gone. After hibernation, Linux needs to
re-negotiate with the host using the same vmbus protocol version (which
was in use before hibernation), and ask the host to re-offer the vmbus
devices.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The high-level VSC drivers will implement device-specific callbacks.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This is needed when we resume the old kernel from the "current" kernel.
Note: when hv_synic_suspend() and hv_synic_resume() run, all the
non-boot CPUs have been offlined, and interrupts are disabled on CPU0.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range. This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.
On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.
The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:
$ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
248
Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.
This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:
# scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
Data old new delta
sysctl_vals - 12 +12
__kstrtab_sysctl_vals - 12 +12
max 14 10 -4
int_max 16 - -16
one 68 - -68
zero 128 28 -100
Total: Before=20583249, After=20583085, chg -0.00%
[mcroce@redhat.com: tipc: remove two unused variables]
Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Rework some vmbus code to separate architecture specifics out to
arch/x86/. This is part of the work of adding arm64 support to Hyper-V.
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyper-v updates from Sasha Levin:
- Add a module description to the Hyper-V vmbus module.
- Rework some vmbus code to separate architecture specifics out to
arch/x86/. This is part of the work of adding arm64 support to
Hyper-V.
* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
Drivers: hv: vmbus: Break out ISA independent parts of mshyperv.h
drivers: hv: Add a module description line to the hv_vmbus driver
Hyper-V clock/timer code and data structures are currently mixed
in with other code in the ISA independent drivers/hv directory as
well as the ISA dependent Hyper-V code under arch/x86.
Consolidate this code and data structures into a Hyper-V clocksource driver
to better follow the Linux model. In doing so, separate out the ISA
dependent portions so the new clocksource driver works for x86 and for the
in-process Hyper-V on ARM64 code.
To start, move the existing clockevents code to create the new clocksource
driver. Update the VMbus driver to call initialization and cleanup routines
since the Hyper-V synthetic timers are not independently enumerated in
ACPI.
No behavior is changed and no new functionality is added.
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "bp@alien8.de" <bp@alien8.de>
Cc: "will.deacon@arm.com" <will.deacon@arm.com>
Cc: "catalin.marinas@arm.com" <catalin.marinas@arm.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>
Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>
Cc: "olaf@aepfle.de" <olaf@aepfle.de>
Cc: "apw@canonical.com" <apw@canonical.com>
Cc: "jasowang@redhat.com" <jasowang@redhat.com>
Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>
Cc: Sunil Muthuswamy <sunilmut@microsoft.com>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: "sashal@kernel.org" <sashal@kernel.org>
Cc: "vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>
Cc: "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>
Cc: "arnd@arndb.de" <arnd@arndb.de>
Cc: "linux@armlinux.org.uk" <linux@armlinux.org.uk>
Cc: "ralf@linux-mips.org" <ralf@linux-mips.org>
Cc: "paul.burton@mips.com" <paul.burton@mips.com>
Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>
Cc: "salyzyn@android.com" <salyzyn@android.com>
Cc: "pcc@google.com" <pcc@google.com>
Cc: "shuah@kernel.org" <shuah@kernel.org>
Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com>
Cc: "linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk>
Cc: "huw@codeweavers.com" <huw@codeweavers.com>
Cc: "sfr@canb.auug.org.au" <sfr@canb.auug.org.au>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>
Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Link: https://lkml.kernel.org/r/1561955054-1838-2-git-send-email-mikelley@microsoft.com
This patch only adds a MODULE_DESCRIPTION statement to the driver.
This change is only cosmetic, so there should be no runtime impact.
Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 59 temple place suite 330 boston ma 02111
1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 33 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000435.254582722@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix a race condition that can result in a ring buffer pointer being set
to null while a "_show" function is reading the ring buffer's data. This
problem was discussed here: https://lkml.org/lkml/2018/10/18/779
To fix the race condition, add a new mutex lock to the
"hv_ring_buffer_info" struct. Add a new function,
"hv_ringbuffer_pre_init()", where a channel's inbound and outbound
ring_buffer_info mutex locks are initialized.
Acquire/release the locks in the "hv_ringbuffer_cleanup()" function,
which is where the ring buffer pointers are set to null.
Acquire/release the locks in the four channel-level "_show" functions
that access ring buffer data. Remove the "const" qualifier from the
"vmbus_channel" parameter and the "rbi" variable of the channel-level
"_show" functions so that the locks can be acquired/released in these
functions.
Acquire/release the locks in hv_ringbuffer_get_debuginfo(). Remove the
"const" qualifier from the "hv_ring_buffer_info" parameter so that the
locks can be acquired/released in this function.
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The chan->state "if statement" was introduced in commit 6712cc9c22
("vmbus: don't return values for uninitalized channels"). That commit
states that the purpose of the chan->state "if statement" is to prevent
returning garbage or causing a kernel OOPS when the channel ring buffer
is not initialized. The changes in this patch provide the same
protection.
Refactor the chan->state “if statement” in vmbus_chan_attr_show():
- Instead of checking the channel state in the "if statement", check
whether the channel ring buffer pointer is NULL. Checking the
ring buffer pointer makes this code consistent with
hv_ringbuffer_get_debuginfo().
- Move the "if statement" to the four "_show" functions that access a
channel ring buffer. Only four of the channel-level "_show" functions
access a ring buffer. The ring buffer pointer does not need to be
checked before calling the other "_show" functions, and moving the
ring buffer pointer "if statement" to the "_show" functions that
access a ring buffer makes the purpose of the "if statement" clear.
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
There are two methods for signaling the host: the monitor page mechanism
and hypercalls. The monitor page mechanism is used by performance
critical channels (storage, networking, etc.) because it provides
improved throughput. However, latency is increased. Monitor pages are
allocated to these channels.
Monitor pages are not allocated to channels that do not use the monitor
page mechanism. Therefore, these channels do not have a valid monitor id
or valid monitor page data. In these cases, some of the "_show"
functions return incorrect data. They return an invalid monitor id and
data that is beyond the bounds of the hv_monitor_page array fields.
The "channel->offermsg.monitor_allocated" value can be used to determine
whether monitor pages have been allocated to a channel.
Add "is_visible()" callback functions for the device-level and
channel-level attribute groups. These functions will hide the monitor
sysfs files when the monitor mechanism is not used.
Remove ".default_attributes" from "vmbus_chan_attrs" and create a
channel-level attribute group. These changes allow the new
"is_visible()" callback function to be applied to the channel-level
attributes.
Call "sysfs_create_group()" in "vmbus_add_channel_kobj()" to create the
channel's sysfs files. Add a new function,
“vmbus_remove_channel_attr_group()”, and call it in "free_channel()" to
remove the channel's sysfs files when the channel is closed.
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
useful to investigate performance issues. By Kimberly Brown.
2. Switching to the new generic UUID API, by Andy Shevchenko.
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux into char-misc-next
Sasha writes:
1. Exopsing counters for state changes of channel ring buffers; this is
useful to investigate performance issues. By Kimberly Brown.
2. Switching to the new generic UUID API, by Andy Shevchenko.
* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
Drivers: hv: vmbus: Expose counters for interrupts and full conditions
vmbus: Switch to use new generic UUID API
Change the monitor_pages index in server_monitor_pending_show() to '0'.
'0' is the correct monitor_pages index for the server. A comment for the
monitor_pages field in the vmbus_connection struct definition indicates
that the 1st page is for parent->child notifications. In addition, the
server_monitor_latency_show() and server_monitor_conn_id_show()
functions use monitor_pages index '0'.
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Counter values for per-channel interrupts and ring buffer full
conditions are useful for investigating performance.
Expose counters in sysfs for 2 types of guest to host interrupts:
1) Interrupts caused by the channel's outbound ring buffer transitioning
from empty to not empty
2) Interrupts caused by the channel's inbound ring buffer transitioning
from full to not full while a packet is waiting for enough buffer space to
become available
Expose 2 counters in sysfs for the number of times that write operations
encountered a full outbound ring buffer:
1) The total number of write operations that encountered a full
condition
2) The number of write operations that were the first to encounter a
full condition
Increment the outbound full condition counters in the
hv_ringbuffer_write() function because, for most drivers, a full
outbound ring buffer is detected in that function. Also increment the
outbound full condition counters in the set_channel_pending_send_size()
function. In the hv_sock driver, a full outbound ring buffer is detected
and set_channel_pending_send_size() is called before
hv_ringbuffer_write() is called.
I tested this patch by confirming that the sysfs files were created and
observing the counter values. The values seemed to increase by a
reasonable amount when the Hyper-v related drivers were in use.
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
There are new types and helpers that are supposed to be used in new code.
As a preparation to get rid of legacy types and API functions do
the conversion here.
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: devel@linuxdriverproject.org
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fc96df16a1 is good and can already fix the "return stack garbage" issue,
but let's also improve hv_ringbuffer_get_debuginfo(), which would silently
return stack garbage, if people forget to check channel->state or
ring_info->ring_buffer, when using the function in the future.
Having an error check in the function would eliminate the potential risk.
Add a Fixes tag to indicate the patch depdendency.
Fixes: fc96df16a1 ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels")
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Before 98f4c65176, we returned zeros for unopened channels.
With 98f4c65176, we started to return random on-stack values.
We'd better return -EINVAL instead.
Fixes: 98f4c65176 ("hv: move ringbuffer bus attributes to dev_groups")
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Rather than passing relid and then looking up the channel.
Pass the channel directly, since caller already knows it.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For unsupported device types, the vmbus channel ringbuffer is never
initialized, and therefore reading the sysfs files will return garbage
or cause a kernel OOPS.
Fixes: c2e5df616e ("vmbus: add per-channel sysfs info")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org> # 4.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
