[ Upstream commit d5a9597d6916a76663085db984cb8fe97f0a5c56 ]

Today, all possible serial lines (ssl*=) as well as all
possible consoles (con*=) each share a single interrupt
(with a fixed number) with others of the same type.

Now, if you have two lines, say ssl0 and ssl1, and one
of them is connected to an fd you cannot read (e.g. a
file), but the other gets a read interrupt, then both
of them get the interrupt since it's shared. Then, the
read() call will return EOF, since it's a file being
written and there's nothing to read (at least not at
the current offset, at the end).

Unfortunately, this is treated as a read error, and we
close this line, losing all the possible output.

It might be possible to work around this and make the
IRQ sharing work, however, now that we have dynamically
allocated IRQs that are easy to use, simply use that to
achieve separating between the events; then there's no
interrupt for that line and we never attempt the read
in the first place, thus not closing the line.

This manifested itself in the wifi hostap/hwsim tests
where the parallel script communicates via one serial
console and the kernel messages go to another (a file)
and sending data on the communication console caused
the kernel messages to stop flowing into the file.

Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: anton ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 57ae0b67b747031bc41fb44643aa5344ab58607e upstream.

The previous fix here was only partially correct, it did
result in returning a proper error value in case of error,
but it also clobbered the pid that we need to return from
this function (not just zero for success).

As a result, it returned 0 here, but later this is treated
as a pid and used to kill the process, but since it's now
0 we kill(0, SIGKILL), which makes UML kill itself rather
than just the helper thread.

Fix that and make it more obvious by using a separate
variable for the pid.

Fixes: ccf1236ecac4 ("um: fix error return code in winch_tramp()")
Reported-and-tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit af9fb41ed315ce95f659f0b10b4d59a71975381d upstream.

If a device implementation crashes, virtio_uml will mark it
as dead by calling virtio_break_device() and scheduling the
work that will remove it.

This still seems like the right thing to do, but it's done
directly while reading the message, and if time-travel is
used, this is in the time-travel handler, outside of the
normal Linux machinery. Therefore, we cannot acquire locks
or do normal "linux-y" things because e.g. lockdep will be
confused about the context.

Move handling this situation out of the read function and
into the actual IRQ handler and response handling instead,
so that in the case of time-travel we don't call it in the
wrong context.

Chances are the system will still crash immediately, since
the device implementation crashing may also cause the time-
travel controller to go down, but at least all of that now
happens without strange warnings from lockdep.

Fixes: c8177aba37ca ("um: time-travel: rework interrupt handling in ext mode")
Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1a3a6a2a035bb6c3a7ef4c788d8fd69a7b2d6284 upstream.

Moving to an EPOLL based IRQ controller broke uml_mconsole stop/go
commands. This fixes it and restores stop/go functionality.

Fixes: ff6a17989c08 ("Epoll based IRQ controller")
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull virtio updates from Michael Tsirkin:
 "virtio,vdpa,qemu_fw_cfg: features, cleanups, and fixes.

   - partial support for < MAX_ORDER - 1 granularity for virtio-mem

   - driver_override for vdpa

   - sysfs ABI documentation for vdpa

   - multiqueue config support for mlx5 vdpa

   - and misc fixes, cleanups"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (42 commits)
  vdpa/mlx5: Fix tracking of current number of VQs
  vdpa/mlx5: Fix is_index_valid() to refer to features
  vdpa: Protect vdpa reset with cf_mutex
  vdpa: Avoid taking cf_mutex lock on get status
  vdpa/vdpa_sim_net: Report max device capabilities
  vdpa: Use BIT_ULL for bit operations
  vdpa/vdpa_sim: Configure max supported virtqueues
  vdpa/mlx5: Report max device capabilities
  vdpa: Support reporting max device capabilities
  vdpa/mlx5: Restore cur_num_vqs in case of failure in change_num_qps()
  vdpa: Add support for returning device configuration information
  vdpa/mlx5: Support configuring max data virtqueue
  vdpa/mlx5: Fix config_attr_mask assignment
  vdpa: Allow to configure max data virtqueues
  vdpa: Read device configuration only if FEATURES_OK
  vdpa: Sync calls set/get config/status with cf_mutex
  vdpa/mlx5: Distribute RX virtqueues in RQT object
  vdpa: Provide interface to read driver features
  vdpa: clean up get_config_size ret value handling
  virtio_ring: mark ring unused on error
  ...

This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Pull UML updates from Richard Weinberger:

 - set_fs removal

 - Devicetree support

 - Many cleanups from Al

 - Various virtio and build related fixes

* tag 'for-linus-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (31 commits)
  um: virtio_uml: Allow probing from devicetree
  um: Add devicetree support
  um: Extract load file helper from initrd.c
  um: remove set_fs
  hostfs: Fix writeback of dirty pages
  um: Use swap() to make code cleaner
  um: header debriding - sigio.h
  um: header debriding - os.h
  um: header debriding - net_*.h
  um: header debriding - mem_user.h
  um: header debriding - activate_ipi()
  um: common-offsets.h debriding...
  um, x86: bury crypto_tfm_ctx_offset
  um: unexport handle_page_fault()
  um: remove a dangling extern of syscall_trace()
  um: kill unused cpu()
  uml/i386: missing include in barrier.h
  um: stop polluting the namespace with registers.h contents
  logic_io instance of iounmap() needs volatile on argument
  um: move amd64 variant of mmap(2) to arch/x86/um/syscalls_64.c
  ...

Allow the virtio_uml device to be probed from the devicetree so that
sub-devices can be specified using the standard virtio bindings, for
example:

  virtio@1 {
    compatible = "virtio,uml";
    socket-path = "i2c.sock";
    virtio-device-id = <0x22>;

    i2c-controller {
      compatible = "virtio,device22";
      #address-cells = <0x01>;
      #size-cells = <0x00>;

      light-sensor@01 {
        compatible = "ti,opt3001";
        reg = <0x01>;
      };
    };
  };

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

When creating an external event, the current time needs to
be propagated to other participants of a simulation. This
is done in the places here where we kick a virtq etc.

However, it must be done for _all_ external events, and
that includes making the initial socket connection and
later closing it. Call time_travel_propagate_time() to do
this before making or closing the socket connection.

Apparently, at least for the initial connection creation,
due to the remote side in my use cases using microseconds
(rather than nanoseconds), this wasn't a problem yet; only
started failing between 5.14-rc1 and 5.15-rc1 (didn't test
others much), or possibly depending on the configuration,
where more delays happen before the virtio devices are
initialized.

Fixes: 88ce64249233 ("um: Implement time-travel=ext")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

There were a few 32-bit compile warnings that of course
turned into errors with -Werror, fix the 32-bit build.

Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>