linux-stable.git/drivers/xen, branch v4.4.280

xen/events: reset active flag for lateeoi events later

2021-07-11T10:45:27+00:00

commit 3de218ff39b9e3f0d453fe3154f12a174de44b25 upstream.

In order to avoid a race condition for user events when changing
cpu affinity reset the active flag only when EOI-ing the event.

This is working fine as all user events are lateeoi events. Note that
lateeoi_ack_mask_dynirq() is not modified as there is no explicit call
to xen_irq_lateeoi() expected later.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall 
Fixes: b6622798bc50b62 ("xen/events: avoid handling the same event on two cpus at the same time")
Tested-by: Julien Grall 
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Link: https://lore.kernel.org/r/20210623130913.9405-1-jgross@suse.com
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen-pciback: redo VF placement in the virtual topology

2021-06-10T10:41:36+00:00

The commit referenced below was incomplete: It merely affected what
would get written to the vdev- xenstore node. The guest would still
find the function at the original function number as long as
__xen_pcibk_get_pci_dev() wouldn't be in sync. The same goes for AER wrt
__xen_pcibk_get_pcifront_dev().

Undo overriding the function to zero and instead make sure that VFs at
function zero remain alone in their slot. This has the added benefit of
improving overall capacity, considering that there's only a total of 32
slots available right now (PCI segment and bus can both only ever be
zero at present).

This is upstream commit 4ba50e7c423c29639878c00573288869aa627068.

Fixes: 8a5248fe10b1 ("xen PV passthru: assign SR-IOV virtual functions to 
separate virtual slots")
Signed-off-by: Jan Beulich 
Reviewed-by: Boris Ostrovsky 
Link: https://lore.kernel.org/r/8def783b-404c-3452-196d-3f3fd4d72c9e@suse.com
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen-pciback: reconfigure also from backend watch handler

2021-05-26T09:27:32+00:00

commit c81d3d24602540f65256f98831d0a25599ea6b87 upstream.

When multiple PCI devices get assigned to a guest right at boot, libxl
incrementally populates the backend tree. The writes for the first of
the devices trigger the backend watch. In turn xen_pcibk_setup_backend()
will set the XenBus state to Initialised, at which point no further
reconfigures would happen unless a device got hotplugged. Arrange for
reconfigure to also get triggered from the backend watch handler.

Signed-off-by: Jan Beulich 
Cc: stable@vger.kernel.org
Reviewed-by: Boris Ostrovsky 
Link: https://lore.kernel.org/r/2337cbd6-94b9-4187-9862-c03ea12e0c61@suse.com
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/events: fix setting irq affinity

2021-04-16T10:00:23+00:00

The backport of upstream patch 25da4618af240fbec61 ("xen/events: don't
unmask an event channel when an eoi is pending") introduced a
regression for stable kernels 5.10 and older: setting IRQ affinity for
IRQs related to interdomain events would no longer work, as moving the
IRQ to its new cpu was not included in the irq_ack callback for those
events.

Fix that by adding the needed call.

Note that kernels 5.11 and later don't need the explicit moving of the
IRQ to the target cpu in the irq_ack callback, due to a rework of the
affinity setting in kernel 5.11.

Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/evtchn: Change irq_info lock to raw_spinlock_t

2021-04-16T10:00:20+00:00

commit d120198bd5ff1d41808b6914e1eb89aff937415c upstream.

Unmask operation must be called with interrupt disabled,
on preempt_rt spin_lock_irqsave/spin_unlock_irqrestore
don't disable/enable interrupts, so use raw_* implementation
and change lock variable in struct irq_info from spinlock_t
to raw_spinlock_t

Cc: stable@vger.kernel.org
Fixes: 25da4618af24 ("xen/events: don't unmask an event channel when an eoi is pending")
Signed-off-by: Luca Fancellu 
Reviewed-by: Julien Grall 
Reviewed-by: Wei Liu 
Link: https://lore.kernel.org/r/20210406105105.10141-1-luca.fancellu@arm.com
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

xen/events: avoid handling the same event on two cpus at the same time

2021-03-17T15:07:24+00:00

commit b6622798bc50b625a1e62f82c7190df40c1f5b21 upstream.

When changing the cpu affinity of an event it can happen today that
(with some unlucky timing) the same event will be handled on the old
and the new cpu at the same time.

Avoid that by adding an "event active" flag to the per-event data and
call the handler only if this flag isn't set.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall 
Signed-off-by: Juergen Gross 
Reviewed-by: Julien Grall 
Link: https://lore.kernel.org/r/20210306161833.4552-4-jgross@suse.com
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

xen/events: don't unmask an event channel when an eoi is pending

2021-03-17T15:07:24+00:00

commit 25da4618af240fbec6112401498301a6f2bc9702 upstream.

An event channel should be kept masked when an eoi is pending for it.
When being migrated to another cpu it might be unmasked, though.

In order to avoid this keep three different flags for each event channel
to be able to distinguish "normal" masking/unmasking from eoi related
masking/unmasking and temporary masking. The event channel should only
be able to generate an interrupt if all flags are cleared.

Cc: stable@vger.kernel.org
Fixes: 54c9de89895e ("xen/events: add a new "late EOI" evtchn framework")
Reported-by: Julien Grall 
Signed-off-by: Juergen Gross 
Reviewed-by: Julien Grall 
Reviewed-by: Boris Ostrovsky 
Tested-by: Ross Lagerwall 
Link: https://lore.kernel.org/r/20210306161833.4552-3-jgross@suse.com

[boris -- corrected Fixed tag format]

Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

xen/events: reset affinity of 2-level event when tearing it down

2021-03-17T15:07:24+00:00

commit 9e77d96b8e2724ed00380189f7b0ded61113b39f upstream.

When creating a new event channel with 2-level events the affinity
needs to be reset initially in order to avoid using an old affinity
from earlier usage of the event channel port. So when tearing an event
channel down reset all affinity bits.

The same applies to the affinity when onlining a vcpu: all old
affinity settings for this vcpu must be reset. As percpu events get
initialized before the percpu event channel hook is called,
resetting of the affinities happens after offlining a vcpu (this is
working, as initial percpu memory is zeroed out).

Cc: stable@vger.kernel.org
Reported-by: Julien Grall 
Signed-off-by: Juergen Gross 
Reviewed-by: Julien Grall 
Link: https://lore.kernel.org/r/20210306161833.4552-2-jgross@suse.com
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

xen-scsiback: don't "handle" error by BUG()

2021-02-23T12:58:14+00:00

commit 7c77474b2d22176d2bfb592ec74e0f2cb71352c9 upstream.

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.

This is part of XSA-362.

Signed-off-by: Jan Beulich 
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

Xen/gntdev: correct error checking in gntdev_map_grant_pages()

2021-02-23T12:58:14+00:00

commit ebee0eab08594b2bd5db716288a4f1ae5936e9bc upstream.

Failure of the kernel part of the mapping operation should also be
indicated as an error to the caller, or else it may assume the
respective kernel VA is okay to access.

Furthermore gnttab_map_refs() failing still requires recording
successfully mapped handles, so they can be unmapped subsequently. This
in turn requires there to be a way to tell full hypercall failure from
partial success - preset map_op status fields such that they won't
"happen" to look as if the operation succeeded.

Also again use GNTST_okay instead of implying its value (zero).

This is part of XSA-361.

Signed-off-by: Jan Beulich 
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman