linux-stable.git/drivers/xen, branch v4.4.233

xen/balloon: make the balloon wait interruptible

2020-08-21T08:53:04+00:00

commit 88a479ff6ef8af7f07e11593d58befc644244ff7 upstream.

So it can be killed, or else processes can get hung indefinitely
waiting for balloon pages.

Signed-off-by: Roger Pau Monné 
Reviewed-by: Juergen Gross 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200727091342.52325-3-roger.pau@citrix.com
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/balloon: fix accounting in alloc_xenballooned_pages error path

2020-08-21T08:53:04+00:00

commit 1951fa33ec259abdf3497bfee7b63e7ddbb1a394 upstream.

target_unpopulated is incremented with nr_pages at the start of the
function, but the call to free_xenballooned_pages will only subtract
pgno number of pages, and thus the rest need to be subtracted before
returning or else accounting will be skewed.

Signed-off-by: Roger Pau Monné 
Reviewed-by: Juergen Gross 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200727091342.52325-2-roger.pau@citrix.com
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/xenbus: ensure xenbus_map_ring_valloc() returns proper grant status

2020-05-02T15:20:53+00:00

[ Upstream commit 6b51fd3f65a22e3d1471b18a1d56247e246edd46 ]

xenbus_map_ring_valloc() maps a ring page and returns the status of the
used grant (0 meaning success).

There are Xen hypervisors which might return the value 1 for the status
of a failed grant mapping due to a bug. Some callers of
xenbus_map_ring_valloc() test for errors by testing the returned status
to be less than zero, resulting in no error detected and crashing later
due to a not available ring page.

Set the return value of xenbus_map_ring_valloc() to GNTST_general_error
in case the grant status reported by Xen is greater than zero.

This is part of XSA-316.

Signed-off-by: Juergen Gross 
Reviewed-by: Wei Liu 
Link: https://lore.kernel.org/r/20200326080358.1018-1-jgross@suse.com
Signed-off-by: Juergen Gross 
Signed-off-by: Sasha Levin

xen: Enable interrupts when calling _cond_resched()

2020-02-28T14:39:18+00:00

commit 8645e56a4ad6dcbf504872db7f14a2f67db88ef2 upstream.

xen_maybe_preempt_hcall() is called from the exception entry point
xen_do_hypervisor_callback with interrupts disabled.

_cond_resched() evades the might_sleep() check in cond_resched() which
would have caught that and schedule_debug() unfortunately lacks a check
for irqs_disabled().

Enable interrupts around the call and use cond_resched() to catch future
issues.

Fixes: fdfd811ddde3 ("x86/xen: allow privcmd hypercalls to be preempted")
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/878skypjrh.fsf@nanos.tec.linutronix.de
Reviewed-by: Juergen Gross 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

xen, cpu_hotplug: Prevent an out of bounds access

2020-01-29T09:21:41+00:00

[ Upstream commit 201676095dda7e5b31a5e1d116d10fc22985075e ]

The "cpu" variable comes from the sscanf() so Smatch marks it as
untrusted data.  We can't pass a higher value than "nr_cpu_ids" to
cpu_possible() or it results in an out of bounds access.

Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging")
Signed-off-by: Dan Carpenter 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Sasha Levin

xen: let alloc_xenballooned_pages() fail if not enough memory free

2020-01-23T07:18:35+00:00

commit a1078e821b605813b63bf6bca414a85f804d5c66 upstream.

Instead of trying to allocate pages with GFP_USER in
add_ballooned_pages() check the available free memory via
si_mem_available(). GFP_USER is far less limiting memory exhaustion
than the test via si_mem_available().

This will avoid dom0 running out of memory due to excessive foreign
page mappings especially on ARM and on x86 in PVH mode, as those don't
have a pre-ballooned area which can be used for foreign mappings.

As the normal ballooning suffers from the same problem don't balloon
down more than si_mem_available() pages in one iteration. At the same
time limit the default maximum number of retries.

This is part of XSA-300.

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

xen/balloon: fix ballooned page accounting without hotplug enabled

2020-01-12T10:22:40+00:00

[ Upstream commit c673ec61ade89bf2f417960f986bc25671762efb ]

When CONFIG_XEN_BALLOON_MEMORY_HOTPLUG is not defined
reserve_additional_memory() will set balloon_stats.target_pages to a
wrong value in case there are still some ballooned pages allocated via
alloc_xenballooned_pages().

This will result in balloon_process() no longer be triggered when
ballooned pages are freed in batches.

Reported-by: Nicholas Tsirakis 
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross 
Signed-off-by: Sasha Levin

xen/pciback: Check dev_data before using it

2019-12-05T14:26:50+00:00

[ Upstream commit 1669907e3d1abfa3f7586e2d55dbbc117b5adba2 ]

If pcistub_init_device fails, the release function will be called with
dev_data set to NULL.  Check it before using it to avoid a NULL pointer
dereference.

Signed-off-by: Ross Lagerwall 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Sasha Levin

xen/pci: reserve MCFG areas earlier

2019-10-17T20:40:55+00:00

[ Upstream commit a4098bc6eed5e31e0391bcc068e61804c98138df ]

If MCFG area is not reserved in E820, Xen by default will defer its usage
until Dom0 registers it explicitly after ACPI parser recognizes it as
a reserved resource in DSDT. Having it reserved in E820 is not
mandatory according to "PCI Firmware Specification, rev 3.2" (par. 4.1.2)
and firmware is free to keep a hole in E820 in that place. Xen doesn't know
what exactly is inside this hole since it lacks full ACPI view of the
platform therefore it's potentially harmful to access MCFG region
without additional checks as some machines are known to provide
inconsistent information on the size of the region.

Now xen_mcfg_late() runs after acpi_init() which is too late as some basic
PCI enumeration starts exactly there as well. Trying to register a device
prior to MCFG reservation causes multiple problems with PCIe extended
capability initializations in Xen (e.g. SR-IOV VF BAR sizing). There are
no convenient hooks for us to subscribe to so register MCFG areas earlier
upon the first invocation of xen_add_device(). It should be safe to do once
since all the boot time buses must have their MCFG areas in MCFG table
already and we don't support PCI bus hot-plug.

Signed-off-by: Igor Druzhinin 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Sasha Levin

xen/pciback: remove set but not used variable 'old_state'

2019-08-25T08:52:59+00:00

[ Upstream commit 09e088a4903bd0dd911b4f1732b250130cdaffed ]

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/xen/xen-pciback/conf_space_capability.c: In function pm_ctrl_write:
drivers/xen/xen-pciback/conf_space_capability.c:119:25: warning:
 variable old_state set but not used [-Wunused-but-set-variable]

It is never used so can be removed.

Reported-by: Hulk Robot 
Signed-off-by: YueHaibing 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross 
Signed-off-by: Sasha Levin