commit fa765c4b4aed2d64266b694520ecb025c862c5a9 upstream.
shutdown_pirq and startup_pirq are not taking the
irq_mapping_update_lock because they can't due to lock inversion. Both
are called with the irq_desc->lock being taking. The lock order,
however, is first irq_mapping_update_lock and then irq_desc->lock.
This opens multiple races:
- shutdown_pirq can be interrupted by a function that allocates an event
channel:
CPU0 CPU1
shutdown_pirq {
xen_evtchn_close(e)
__startup_pirq {
EVTCHNOP_bind_pirq
-> returns just freed evtchn e
set_evtchn_to_irq(e, irq)
}
xen_irq_info_cleanup() {
set_evtchn_to_irq(e, -1)
}
}
Assume here event channel e refers here to the same event channel
number.
After this race the evtchn_to_irq mapping for e is invalid (-1).
- __startup_pirq races with __unbind_from_irq in a similar way. Because
__startup_pirq doesn't take irq_mapping_update_lock it can grab the
evtchn that __unbind_from_irq is currently freeing and cleaning up. In
this case even though the event channel is allocated, its mapping can
be unset in evtchn_to_irq.
The fix is to first cleanup the mappings and then close the event
channel. In this way, when an event channel gets allocated it's
potential previous evtchn_to_irq mappings are guaranteed to be unset already.
This is also the reverse order of the allocation where first the event
channel is allocated and then the mappings are setup.
On a 5.10 kernel prior to commit 3fcdaf3d7634 ("xen/events: modify internal
[un]bind interfaces"), we hit a BUG like the following during probing of NVMe
devices. The issue is that during nvme_setup_io_queues, pci_free_irq
is called for every device which results in a call to shutdown_pirq.
With many nvme devices it's therefore likely to hit this race during
boot because there will be multiple calls to shutdown_pirq and
startup_pirq are running potentially in parallel.
------------[ cut here ]------------
blkfront: xvda: barrier or flush: disabled; persistent grants: enabled; indirect descriptors: enabled; bounce buffer: enabled
kernel BUG at drivers/xen/events/events_base.c:499!
invalid opcode: 0000 [#1] SMP PTI
CPU: 44 PID: 375 Comm: kworker/u257:23 Not tainted 5.10.201-191.748.amzn2.x86_64 #1
Hardware name: Xen HVM domU, BIOS 4.11.amazon 08/24/2006
Workqueue: nvme-reset-wq nvme_reset_work
RIP: 0010:bind_evtchn_to_cpu+0xdf/0xf0
Code: 5d 41 5e c3 cc cc cc cc 44 89 f7 e8 2b 55 ad ff 49 89 c5 48 85 c0 0f 84 64 ff ff ff 4c 8b 68 30 41 83 fe ff 0f 85 60 ff ff ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00
RSP: 0000:ffffc9000d533b08 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
RDX: 0000000000000028 RSI: 00000000ffffffff RDI: 00000000ffffffff
RBP: ffff888107419680 R08: 0000000000000000 R09: ffffffff82d72b00
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000001ed
R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff88bc8b500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000002610001 CR4: 00000000001706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? show_trace_log_lvl+0x1c1/0x2d9
? show_trace_log_lvl+0x1c1/0x2d9
? set_affinity_irq+0xdc/0x1c0
? __die_body.cold+0x8/0xd
? die+0x2b/0x50
? do_trap+0x90/0x110
? bind_evtchn_to_cpu+0xdf/0xf0
? do_error_trap+0x65/0x80
? bind_evtchn_to_cpu+0xdf/0xf0
? exc_invalid_op+0x4e/0x70
? bind_evtchn_to_cpu+0xdf/0xf0
? asm_exc_invalid_op+0x12/0x20
? bind_evtchn_to_cpu+0xdf/0xf0
? bind_evtchn_to_cpu+0xc5/0xf0
set_affinity_irq+0xdc/0x1c0
irq_do_set_affinity+0x1d7/0x1f0
irq_setup_affinity+0xd6/0x1a0
irq_startup+0x8a/0xf0
__setup_irq+0x639/0x6d0
? nvme_suspend+0x150/0x150
request_threaded_irq+0x10c/0x180
? nvme_suspend+0x150/0x150
pci_request_irq+0xa8/0xf0
? __blk_mq_free_request+0x74/0xa0
queue_request_irq+0x6f/0x80
nvme_create_queue+0x1af/0x200
nvme_create_io_queues+0xbd/0xf0
nvme_setup_io_queues+0x246/0x320
? nvme_irq_check+0x30/0x30
nvme_reset_work+0x1c8/0x400
process_one_work+0x1b0/0x350
worker_thread+0x49/0x310
? process_one_work+0x350/0x350
kthread+0x11b/0x140
? __kthread_bind_mask+0x60/0x60
ret_from_fork+0x22/0x30
Modules linked in:
---[ end trace a11715de1eee1873 ]---
Fixes: d46a78b05c ("xen: implement pirq type event channels")
Cc: stable@vger.kernel.org
Co-debugged-by: Andrew Panyakin <apanyaki@amazon.com>
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20240124163130.31324-1-mheyne@amazon.de
Signed-off-by: Juergen Gross <jgross@suse.com>
[apanyaki: backport to v5.15-stable]
Signed-off-by: Andrew Paniakin <apanyaki@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2d2db7d40254d5fb53b11ebd703cd1ed0c5de7a1 ]
DO NOT access the underlying struct page of an sg table exported
by DMA-buf in dmabuf_imp_to_refs(), this is not allowed.
Please see drivers/dma-buf/dma-buf.c:mangle_sg_table() for details.
Fortunately, here (for special Xen device) we can avoid using
pages and calculate gfns directly from dma addresses provided by
the sg table.
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://lore.kernel.org/r/20240107103426.2038075-1-olekstysh@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit bff2a2d453a1b683378b4508b86b84389f551a00 upstream.
There's a bug that when using the XEN hypervisor with bios with large
multi-page bio vectors on NVMe, the kernel deadlocks [1].
The deadlocks are caused by inability to map a large bio vector -
dma_map_sgtable always returns an error, this gets propagated to the block
layer as BLK_STS_RESOURCE and the block layer retries the request
indefinitely.
XEN uses the swiotlb framework to map discontiguous pages into contiguous
runs that are submitted to the PCIe device. The swiotlb framework has a
limitation on the length of a mapping - this needs to be announced with
the max_mapping_size method to make sure that the hardware drivers do not
create larger mappings.
Without max_mapping_size, the NVMe block driver would create large
mappings that overrun the maximum mapping size.
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Link: https://lore.kernel.org/stable/ZTNH0qtmint%2FzLJZ@mail-itl/ [1]
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/151bef41-e817-aea9-675-a35fdac4ed@redhat.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 47d970204054f859f35a2237baa75c2d84fcf436 ]
When delaying eoi handling of events, the related elements are queued
into the percpu lateeoi list. In case the list isn't empty, the
elements should be sorted by the time when eoi handling is to happen.
Unfortunately a new element will never be queued at the start of the
list, even if it has a handling time lower than all other list
elements.
Fix that by handling that case the same way as for an empty list.
Fixes: e99502f762 ("xen/events: defer eoi in case of excessive number of events")
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2c269f42d0f382743ab230308b836ffe5ae9b2ae ]
Linux enables MSI-X before disabling INTx, but keeps MSI-X masked until
the table is filled. Then it disables INTx just before clearing MASKALL
bit. Currently this approach is rejected by xen-pciback.
According to the PCIe spec, device cannot use INTx when MSI/MSI-X is
enabled (in other words: enabling MSI/MSI-X implicitly disables INTx).
Change the logic to consider INTx disabled if MSI/MSI-X is enabled. This
applies to three places:
- checking currently enabled interrupts type,
- transition to MSI/MSI-X - where INTx would be implicitly disabled,
- clearing INTx disable bit - which can be allowed even if MSI/MSI-X is
enabled, as device should consider INTx disabled anyway in that case
Fixes: 5e29500eba ("xen-pciback: Allow setting PCI_MSIX_FLAGS_MASKALL too")
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20231016131348.1734721-1-marmarek@invisiblethingslab.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 87797fad6c upstream.
In unprivileged Xen guests event handling can cause a deadlock with
Xen console handling. The evtchn_rwlock and the hvc_lock are taken in
opposite sequence in __hvc_poll() and in Xen console IRQ handling.
Normally this is no problem, as the evtchn_rwlock is taken as a reader
in both paths, but as soon as an event channel is being closed, the
lock will be taken as a writer, which will cause read_lock() to block:
CPU0 CPU1 CPU2
(IRQ handling) (__hvc_poll()) (closing event channel)
read_lock(evtchn_rwlock)
spin_lock(hvc_lock)
write_lock(evtchn_rwlock)
[blocks]
spin_lock(hvc_lock)
[blocks]
read_lock(evtchn_rwlock)
[blocks due to writer waiting,
and not in_interrupt()]
This issue can be avoided by replacing evtchn_rwlock with RCU in
xen_free_irq(). Note that RCU is used only to delay freeing of the
irq_info memory. There is no RCU based dereferencing or replacement of
pointers involved.
In order to avoid potential races between removing the irq_info
reference and handling of interrupts, set the irq_info pointer to NULL
only when freeing its memory. The IRQ itself must be freed at that
time, too, as otherwise the same IRQ number could be allocated again
before handling of the old instance would have been finished.
This is XSA-441 / CVE-2023-34324.
Fixes: 54c9de8989 ("xen/events: add a new "late EOI" evtchn framework")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8fafac202d upstream.
In the pvcalls_new_active_socket() function, most error paths call
pvcalls_back_release_active(fedata->dev, fedata, map) which calls
sock_release() on "sock". The bug is that the caller also frees sock.
Fix this by making every error path in pvcalls_new_active_socket()
release the sock, and don't free it in the caller.
Fixes: 5db4d286a8 ("xen/pvcalls: implement connect command")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/e5f98dc2-0305-491f-a860-71bbd1398a2f@kili.mountain
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 073828e954 ]
In ACPI systems, the OS can direct power management, as opposed to the
firmware. This OS-directed Power Management is called OSPM. Part of
telling the firmware that the OS going to direct power management is
making ACPI "_PDC" (Processor Driver Capabilities) calls. These _PDC
methods must be evaluated for every processor object. If these _PDC
calls are not completed for every processor it can lead to
inconsistency and later failures in things like the CPU frequency
driver.
In a Xen system, the dom0 kernel is responsible for system-wide power
management. The dom0 kernel is in charge of OSPM. However, the
number of CPUs available to dom0 can be different than the number of
CPUs physically present on the system.
This leads to a problem: the dom0 kernel needs to evaluate _PDC for
all the processors, but it can't always see them.
In dom0 kernels, ignore the existing ACPI method for determining if a
processor is physically present because it might not be accurate.
Instead, ask the hypervisor for this information.
Fix this by introducing a custom function to use when running as Xen
dom0 in order to check whether a processor object matches a CPU that's
online. Such checking is done using the existing information fetched
by the Xen pCPU subsystem, extending it to also store the ACPI ID.
This ensures that _PDC method gets evaluated for all physically online
CPUs, regardless of the number of CPUs made available to dom0.
Fixes: 5d554a7bb0 ("ACPI: processor: add internal processor_physically_present()")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 073352e951 ]
Some architectures and irqchip drivers modify the cpumask returned by
irq_data_get_affinity_mask, usually by copying in to it. This is
problematic for uniprocessor configurations, where the affinity mask
should be constant, as it is known at compile time.
Add and use a setter for the affinity mask, following the pattern of
irq_data_update_effective_affinity. This allows the getter function to
return a const cpumask pointer.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Xen bits
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220701200056.46555-7-samuel@sholland.org
Stable-dep-of: feabecaff5 ("genirq/ipi: Fix NULL pointer deref in irq_data_get_affinity_mask()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8b997b2bb2 ]
As 'kdata.num' is user-controlled data, if user tries to allocate
memory larger than(>=) MAX_ORDER, then kcalloc() will fail, it
creates a stack trace and messes up dmesg with a warning.
Call trace:
-> privcmd_ioctl
--> privcmd_ioctl_mmap_resource
Add __GFP_NOWARN in order to avoid too large allocation warning.
This is detected by static analysis using smatch.
Fixes: 3ad0876554 ("xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221126050745.778967-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5e29500eba ]
When Xen domain configures MSI-X, the usual approach is to enable MSI-X
together with masking all of them via the config space, then fill the
table and only then clear PCI_MSIX_FLAGS_MASKALL. Allow doing this via
QEMU running in a stub domain.
Previously, when changing PCI_MSIX_FLAGS_MASKALL was not allowed, the
whole write was aborted, preventing change to the PCI_MSIX_FLAGS_ENABLE
bit too.
Note the Xen hypervisor intercepts this write anyway, and may keep the
PCI_MSIX_FLAGS_MASKALL bit set if it wishes to. It will store the
guest-requested state and will apply it eventually.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20221114103110.1519413-1-marmarek@invisiblethingslab.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit da36a2a76b ]
In device_add(), dev_set_name() is called to allocate name, if it returns
error, the name need be freed. As comment of device_register() says, it
should use put_device() to give up the reference in the error path. So fix
this by calling put_device(), then the name can be freed in kobject_cleanup().
Fixes: f65c9bb3fb ("xen/pcpu: Xen physical cpus online/offline sys interface")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221110152441.401630-1-yangyingliang@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5c13a4a029 upstream.
Prior to this commit, the gntdev driver code did not handle the
following scenario correctly with paravirtualized (PV) Xen domains:
* User process sets up a gntdev mapping composed of two grant mappings
(i.e., two pages shared by another Xen domain).
* User process munmap()s one of the pages.
* User process munmap()s the remaining page.
* User process exits.
In the scenario above, the user process would cause the kernel to log
the following messages in dmesg for the first munmap(), and the second
munmap() call would result in similar log messages:
BUG: Bad page map in process doublemap.test pte:... pmd:...
page:0000000057c97bff refcount:1 mapcount:-1 \
mapping:0000000000000000 index:0x0 pfn:...
...
page dumped because: bad pte
...
file:gntdev fault:0x0 mmap:gntdev_mmap [xen_gntdev] readpage:0x0
...
Call Trace:
<TASK>
dump_stack_lvl+0x46/0x5e
print_bad_pte.cold+0x66/0xb6
unmap_page_range+0x7e5/0xdc0
unmap_vmas+0x78/0xf0
unmap_region+0xa8/0x110
__do_munmap+0x1ea/0x4e0
__vm_munmap+0x75/0x120
__x64_sys_munmap+0x28/0x40
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x61/0xcb
...
For each munmap() call, the Xen hypervisor (if built with CONFIG_DEBUG)
would print out the following and trigger a general protection fault in
the affected Xen PV domain:
(XEN) d0v... Attempt to implicitly unmap d0's grant PTE ...
(XEN) d0v... Attempt to implicitly unmap d0's grant PTE ...
As of this writing, gntdev_grant_map structure's vma field (referred to
as map->vma below) is mainly used for checking the start and end
addresses of mappings. However, with split VMAs, these may change, and
there could be more than one VMA associated with a gntdev mapping.
Hence, remove the use of map->vma and rely on map->pages_vm_start for
the original start address and on (map->count << PAGE_SHIFT) for the
original mapping size. Let the invalidate() and find_special_page()
hooks use these.
Also, given that there can be multiple VMAs associated with a gntdev
mapping, move the "mmu_interval_notifier_remove(&map->notifier)" call to
the end of gntdev_put_map, so that the MMU notifier is only removed
after the closing of the last remaining VMA.
Finally, use an atomic to prevent inadvertent gntdev mapping re-use,
instead of using the map->live_grants atomic counter and/or the map->vma
pointer (the latter of which is now removed). This prevents the
userspace from mmap()'ing (with MAP_FIXED) a gntdev mapping over the
same address range as a previously set up gntdev mapping. This scenario
can be summarized with the following call-trace, which was valid prior
to this commit:
mmap
gntdev_mmap
mmap (repeat mmap with MAP_FIXED over the same address range)
gntdev_invalidate
unmap_grant_pages (sets 'being_removed' entries to true)
gnttab_unmap_refs_async
unmap_single_vma
gntdev_mmap (maps the shared pages again)
munmap
gntdev_invalidate
unmap_grant_pages
(no-op because 'being_removed' entries are true)
unmap_single_vma (For PV domains, Xen reports that a granted page
is being unmapped and triggers a general protection fault in the
affected domain, if Xen was built with CONFIG_DEBUG)
The fix for this last scenario could be worth its own commit, but we
opted for a single commit, because removing the gntdev_grant_map
structure's vma field requires guarding the entry to gntdev_mmap(), and
the live_grants atomic counter is not sufficient on its own to prevent
the mmap() over a pre-existing mapping.
Link: https://github.com/QubesOS/qubes-issues/issues/7631
Fixes: ab31523c2f ("xen/gntdev: allow usermode to map granted pages")
Cc: stable@vger.kernel.org
Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221002222006.2077-3-m.v.b@runbox.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0991028cd4 upstream.
Prior to this commit, if a grant mapping operation failed partially,
some of the entries in the map_ops array would be invalid, whereas all
of the entries in the kmap_ops array would be valid. This in turn would
cause the following logic in gntdev_map_grant_pages to become invalid:
for (i = 0; i < map->count; i++) {
if (map->map_ops[i].status == GNTST_okay) {
map->unmap_ops[i].handle = map->map_ops[i].handle;
if (!use_ptemod)
alloced++;
}
if (use_ptemod) {
if (map->kmap_ops[i].status == GNTST_okay) {
if (map->map_ops[i].status == GNTST_okay)
alloced++;
map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
}
}
}
...
atomic_add(alloced, &map->live_grants);
Assume that use_ptemod is true (i.e., the domain mapping the granted
pages is a paravirtualized domain). In the code excerpt above, note that
the "alloced" variable is only incremented when both kmap_ops[i].status
and map_ops[i].status are set to GNTST_okay (i.e., both mapping
operations are successful). However, as also noted above, there are
cases where a grant mapping operation fails partially, breaking the
assumption of the code excerpt above.
The aforementioned causes map->live_grants to be incorrectly set. In
some cases, all of the map_ops mappings fail, but all of the kmap_ops
mappings succeed, meaning that live_grants may remain zero. This in turn
makes it impossible to unmap the successfully grant-mapped pages pointed
to by kmap_ops, because unmap_grant_pages has the following snippet of
code at its beginning:
if (atomic_read(&map->live_grants) == 0)
return; /* Nothing to do */
In other cases where only some of the map_ops mappings fail but all
kmap_ops mappings succeed, live_grants is made positive, but when the
user requests unmapping the grant-mapped pages, __unmap_grant_pages_done
will then make map->live_grants negative, because the latter function
does not check if all of the pages that were requested to be unmapped
were actually unmapped, and the same function unconditionally subtracts
"data->count" (i.e., a value that can be greater than map->live_grants)
from map->live_grants. The side effects of a negative live_grants value
have not been studied.
The net effect of all of this is that grant references are leaked in one
of the above conditions. In Qubes OS v4.1 (which uses Xen's grant
mechanism extensively for X11 GUI isolation), this issue manifests
itself with warning messages like the following to be printed out by the
Linux kernel in the VM that had granted pages (that contain X11 GUI
window data) to dom0: "g.e. 0x1234 still pending", especially after the
user rapidly resizes GUI VM windows (causing some grant-mapping
operations to partially or completely fail, due to the fact that the VM
unshares some of the pages as part of the window resizing, making the
pages impossible to grant-map from dom0).
The fix for this issue involves counting all successful map_ops and
kmap_ops mappings separately, and then adding the sum to live_grants.
During unmapping, only the number of successfully unmapped grants is
subtracted from live_grants. The code is also modified to check for
negative live_grants values after the subtraction and warn the user.
Link: https://github.com/QubesOS/qubes-issues/issues/7631
Fixes: dbe97cff7d ("xen/gntdev: Avoid blocking in unmap_grant_pages()")
Cc: stable@vger.kernel.org
Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>
Acked-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221002222006.2077-2-m.v.b@runbox.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e9ea0b30ad ]
The change from kcalloc() to kvmalloc() means that arg->nr_pages
might now be large enough that the "args->nr_pages << PAGE_SHIFT" can
result in an integer overflow.
Fixes: b3f7931f5c ("xen/gntdev: switch from kcalloc() to kvcalloc()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/YxDROJqu/RPvR0bi@kili
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c5deb27895 upstream.
The error exit of privcmd_ioctl_dm_op() is calling unlock_pages()
potentially with pages being NULL, leading to a NULL dereference.
Additionally lock_pages() doesn't check for pin_user_pages_fast()
having been completely successful, resulting in potentially not
locking all pages into memory. This could result in sporadic failures
when using the related memory in user mode.
Fix all of that by calling unlock_pages() always with the real number
of pinned pages, which will be zero in case pages being NULL, and by
checking the number of pages pinned by pin_user_pages_fast() matching
the expected number of pages.
Cc: <stable@vger.kernel.org>
Fixes: ab520be8cd ("xen/privcmd: Add IOCTL_PRIVCMD_DM_OP")
Reported-by: Rustam Subkhankulov <subkhankulov@ispras.ru>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20220825141918.3581-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 32ad11127b upstream.
This code tries to store -EFAULT in an unsigned int. The
xenbus_file_read() function returns type ssize_t so the negative value
is returned as a positive value to the user.
This change forces another change to the min() macro. Originally, the
min() macro used "unsigned" type which checkpatch complains about. Also
unsigned type would break if "len" were not capped at MAX_RW_COUNT. Use
size_t for the min(). (No effect on runtime for the min_t() change).
Fixes: 2fb3683e7b ("xen: Add xenbus device driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/YutxJUaUYRG/VLVc@kili
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 166d386323 ]
The error paths of gntdev_mmap() can call unmap_grant_pages() even
though not all of the pages have been successfully mapped. This will
trigger the WARN_ON()s in __unmap_grant_pages_done(). The number of
warnings can be very large; I have observed thousands of lines of
warnings in the systemd journal.
Avoid this problem by only warning on unmapping failure if the handle
being unmapped is not INVALID_GRANT_HANDLE. The handle field of any
page that was not successfully mapped will be INVALID_GRANT_HANDLE, so
this catches all cases where unmapping can legitimately fail.
Fixes: dbe97cff7d ("xen/gntdev: Avoid blocking in unmap_grant_pages()")
Cc: stable@vger.kernel.org
Suggested-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220710230522.1563-1-demi@invisiblethingslab.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit dbe97cff7d upstream.
unmap_grant_pages() currently waits for the pages to no longer be used.
In https://github.com/QubesOS/qubes-issues/issues/7481, this lead to a
deadlock against i915: i915 was waiting for gntdev's MMU notifier to
finish, while gntdev was waiting for i915 to free its pages. I also
believe this is responsible for various deadlocks I have experienced in
the past.
Avoid these problems by making unmap_grant_pages async. This requires
making it return void, as any errors will not be available when the
function returns. Fortunately, the only use of the return value is a
WARN_ON(), which can be replaced by a WARN_ON when the error is
detected. Additionally, a failed call will not prevent further calls
from being made, but this is harmless.
Because unmap_grant_pages is now async, the grant handle will be sent to
INVALID_GRANT_HANDLE too late to prevent multiple unmaps of the same
handle. Instead, a separate bool array is allocated for this purpose.
This wastes memory, but stuffing this information in padding bytes is
too fragile. Furthermore, it is necessary to grab a reference to the
map before making the asynchronous call, and release the reference when
the call returns.
It is also necessary to guard against reentrancy in gntdev_map_put(),
and to handle the case where userspace tries to map a mapping whose
contents have not all been freed yet.
Fixes: 745282256c ("xen/gntdev: safely unmap grants in case they are still in use")
Cc: stable@vger.kernel.org
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220622022726.2538-1-demi@invisiblethingslab.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit dbac14a5a0 ]
EXPORT_SYMBOL and __init is a bad combination because the .init.text
section is freed up after the initialization. Hence, modules cannot
use symbols annotated __init. The access to a freed symbol may end up
with kernel panic.
modpost used to detect it, but it has been broken for a decade.
Recently, I fixed modpost so it started to warn it again, then this
showed up in linux-next builds.
There are two ways to fix it:
- Remove __init
- Remove EXPORT_SYMBOL
I chose the latter for this case because none of the in-tree call-sites
(arch/arm/xen/enlighten.c, arch/x86/xen/grant-table.c) is compiled as
modular.
Fixes: 243848fc01 ("xen/grant-table: Move xlated_setup_gnttab_pages to common place")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20220606045920.4161881-1-masahiroy@kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e81e99bacc upstream.
Add an argument to swiotlb_tbl_map_single that specifies the desired
alignment of the allocated buffer. This is used by dma-iommu to ensure
the buffer is aligned to the iova granule size when using swiotlb with
untrusted sub-granule mappings. This addresses an issue where adjacent
slots could be exposed to the untrusted device if IO_TLB_SIZE < iova
granule < PAGE_SIZE.
Signed-off-by: David Stevens <stevensd@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210929023300.335969-7-stevensd@google.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Cc: Mario Limonciello <Mario.Limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 42baefac63 upstream.
gnttab_end_foreign_access() is used to free a grant reference and
optionally to free the associated page. In case the grant is still in
use by the other side processing is being deferred. This leads to a
problem in case no page to be freed is specified by the caller: the
caller doesn't know that the page is still mapped by the other side
and thus should not be used for other purposes.
The correct way to handle this situation is to take an additional
reference to the granted page in case handling is being deferred and
to drop that reference when the grant reference could be freed
finally.
This requires that there are no users of gnttab_end_foreign_access()
left directly repurposing the granted page after the call, as this
might result in clobbered data or information leaks via the not yet
freed grant reference.
This is part of CVE-2022-23041 / XSA-396.
Reported-by: Simon Gaiser <simon@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit b0576cc9c6 upstream.
Instead of __get_free_pages() and free_pages() use alloc_pages_exact()
and free_pages_exact(). This is in preparation of a change of
gnttab_end_foreign_access() which will prohibit use of high-order
pages.
This is part of CVE-2022-23041 / XSA-396.
Reported-by: Simon Gaiser <simon@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 1dbd11ca75 upstream.
Remove gnttab_query_foreign_access(), as it is unused and unsafe to
use.
All previous use cases assumed a grant would not be in use after
gnttab_query_foreign_access() returned 0. This information is useless
in best case, as it only refers to a situation in the past, which could
have changed already.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit d3b6372c58 upstream.
Using gnttab_query_foreign_access() is unsafe, as it is racy by design.
The use case in the gntalloc driver is not needed at all. While at it
replace the call of gnttab_end_foreign_access_ref() with a call of
gnttab_end_foreign_access(), which is what is really wanted there. In
case the grant wasn't used due to an allocation failure, just free the
grant via gnttab_free_grant_reference().
This is CVE-2022-23039 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 6b1775f26a upstream.
Add a new grant table function gnttab_try_end_foreign_access(), which
will remove and free a grant if it is not in use.
Its main use case is to either free a grant if it is no longer in use,
or to take some other action if it is still in use. This other action
can be an error exit, or (e.g. in the case of blkfront persistent grant
feature) some special handling.
This is CVE-2022-23036, CVE-2022-23038 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3777ea7bac upstream.
Letting xenbus_grant_ring() tear down grants in the error case is
problematic, as the other side could already have used these grants.
Calling gnttab_end_foreign_access_ref() without checking success is
resulting in an unclear situation for any caller of xenbus_grant_ring()
as in the error case the memory pages of the ring page might be
partially mapped. Freeing them would risk unwanted foreign access to
them, while not freeing them would leak memory.
In order to remove the need to undo any gnttab_grant_foreign_access()
calls, use gnttab_alloc_grant_references() to make sure no further
error can occur in the loop granting access to the ring pages.
It should be noted that this way of handling removes leaking of
grant entries in the error case, too.
This is CVE-2022-23040 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ce2f46f353 upstream.
While working with Xen's libxenvchan library I have faced an issue with
unmap notifications sent in wrong order if both UNMAP_NOTIFY_SEND_EVENT
and UNMAP_NOTIFY_CLEAR_BYTE were requested: first we send an event channel
notification and then clear the notification byte which renders in the below
inconsistency (cli_live is the byte which was requested to be cleared on unmap):
[ 444.514243] gntdev_put_map UNMAP_NOTIFY_SEND_EVENT map->notify.event 6
libxenvchan_is_open cli_live 1
[ 444.515239] __unmap_grant_pages UNMAP_NOTIFY_CLEAR_BYTE at 14
Thus it is not possible to reliably implement the checks like
- wait for the notification (UNMAP_NOTIFY_SEND_EVENT)
- check the variable (UNMAP_NOTIFY_CLEAR_BYTE)
because it is possible that the variable gets checked before it is cleared
by the kernel.
To fix that we need to re-order the notifications, so the variable is first
gets cleared and then the event channel notification is sent.
With this fix I can see the correct order of execution:
[ 54.522611] __unmap_grant_pages UNMAP_NOTIFY_CLEAR_BYTE at 14
[ 54.537966] gntdev_put_map UNMAP_NOTIFY_SEND_EVENT map->notify.event 6
libxenvchan_is_open cli_live 0
Cc: stable@vger.kernel.org
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20211210092817.580718-1-andr2000@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fe415186b4 upstream.
The Xen console driver is still vulnerable for an attack via excessive
number of events sent by the backend. Fix that by using a lateeoi event
channel.
For the normal domU initial console this requires the introduction of
bind_evtchn_to_irq_lateeoi() as there is no xenbus device available
at the time the event channel is bound to the irq.
As the decision whether an interrupt was spurious or not requires to
test for bytes having been read from the backend, move sending the
event into the if statement, as sending an event without having found
any bytes to be read is making no sense at all.
This is part of XSA-391
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 36e8f60f08 upstream.
If the xenstore page hasn't been allocated properly, reading the value
of the related hvm_param (HVM_PARAM_STORE_PFN) won't actually return
error. Instead, it will succeed and return zero. Instead of attempting
to xen_remap a bad guest physical address, detect this condition and
return early.
Note that although a guest physical address of zero for
HVM_PARAM_STORE_PFN is theoretically possible, it is not a good choice
and zero has never been validly used in that capacity.
Also recognize all bits set as an invalid value.
For 32-bit Linux, any pfn above ULONG_MAX would get truncated. Pfns
above ULONG_MAX should never be passed by the Xen tools to HVM guests
anyway, so check for this condition and return early.
Cc: stable@vger.kernel.org
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20211123210748.1910236-1-sstabellini@kernel.org
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 08f6c2b09e upstream.
In case of errors in xenbus_init (e.g. missing xen_store_gfn parameter),
we goto out_error but we forget to reset xen_store_domain_type to
XS_UNKNOWN. As a consequence xenbus_probe_initcall and other initcalls
will still try to initialize xenstore resulting into a crash at boot.
[ 2.479830] Call trace:
[ 2.482314] xb_init_comms+0x18/0x150
[ 2.486354] xs_init+0x34/0x138
[ 2.489786] xenbus_probe+0x4c/0x70
[ 2.498432] xenbus_probe_initcall+0x2c/0x7c
[ 2.503944] do_one_initcall+0x54/0x1b8
[ 2.507358] kernel_init_freeable+0x1ac/0x210
[ 2.511617] kernel_init+0x28/0x130
[ 2.516112] ret_from_fork+0x10/0x20
Cc: <Stable@vger.kernel.org>
Cc: jbeulich@suse.com
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Link: https://lore.kernel.org/r/20211115222719.2558207-1-sstabellini@kernel.org
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4745ea2628 ]
Return NULL instead of passing to ERR_PTR while err is zero,
this fix smatch warnings:
drivers/xen/xen-pciback/conf_space_capability.c:163
pm_ctrl_init() warn: passing zero to 'ERR_PTR'
Fixes: a92336a117 ("xen/pciback: Drop two backends, squash and cleanup some code.")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20211008074417.8260-1-yuehaibing@huawei.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 40fdea0284 upstream.
When running as PVH or HVM guest with actual memory < max memory the
hypervisor is using "populate on demand" in order to allow the guest
to balloon down from its maximum memory size. For this to work
correctly the guest must not touch more memory pages than its target
memory size as otherwise the PoD cache will be exhausted and the guest
is crashed as a result of that.
In extreme cases ballooning down might not be finished today before
the init process is started, which can consume lots of memory.
In order to avoid random boot crashes in such cases, add a late init
call to wait for ballooning down having finished for PVH/HVM guests.
Warn on console if initial ballooning fails, panic() after stalling
for more than 3 minutes per default. Add a module parameter for
changing this timeout.
[boris: replaced pr_info() with pr_notice()]
Cc: <stable@vger.kernel.org>
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20211102091944.17487-1-jgross@suse.com
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'for-linus-5.15b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
- fix two minor issues in the Xen privcmd driver plus a cleanup patch
for that driver
- fix multiple issues related to running as PVH guest and some related
earlyprintk fixes for other Xen guest types
- fix an issue introduced in 5.15 the Xen balloon driver
* tag 'for-linus-5.15b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/balloon: fix cancelled balloon action
xen/x86: adjust data placement
x86/PVH: adjust function/data placement
xen/x86: hook up xen_banner() also for PVH
xen/x86: generalize preferred console model from PV to PVH Dom0
xen/x86: make "earlyprintk=xen" work for HVM/PVH DomU
xen/x86: allow "earlyprintk=xen" to work for PV Dom0
xen/x86: make "earlyprintk=xen" work better for PVH Dom0
xen/x86: allow PVH Dom0 without XEN_PV=y
xen/x86: prevent PVH type from getting clobbered
xen/privcmd: drop "pages" parameter from xen_remap_pfn()
xen/privcmd: fix error handling in mmap-resource processing
xen/privcmd: replace kcalloc() by kvcalloc() when allocating empty pages
In case a ballooning action is cancelled the new kernel thread handling
the ballooning might end up in a busy loop.
Fix that by handling the cancelled action gracefully.
While at it introduce a short wait for the BP_WAIT case.
Cc: stable@vger.kernel.org
Fixes: 8480ed9c2b ("xen/balloon: use a kernel thread instead a workqueue")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20211005133433.32008-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Decouple XEN_DOM0 from XEN_PV, converting some existing uses of XEN_DOM0
to a new XEN_PV_DOM0. (I'm not convinced all are really / should really
be PV-specific, but for starters I've tried to be conservative.)
For PVH Dom0 the hypervisor populates MADT with only x2APIC entries, so
without x2APIC support enabled in the kernel things aren't going to work
very well. (As opposed, DomU-s would only ever see LAPIC entries in MADT
as of now.) Note that this then requires PVH Dom0 to be 64-bit, as
X86_X2APIC depends on X86_64.
In the course of this xen_running_on_version_or_later() needs to be
available more broadly. Move it from a PV-specific to a generic file,
considering that what it does isn't really PV-specific at all anyway.
Note that xen/interface/version.h cannot be included on its own; in
enlighten.c, which uses SCHEDOP_* anyway, include xen/interface/sched.h
first to resolve the apparently sole missing type (xen_ulong_t).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/983bb72f-53df-b6af-14bd-5e088bd06a08@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
The function doesn't use it and all of its callers say in a comment that
their respective arguments are to be non-NULL only in auto-translated
mode. Since xen_remap_domain_mfn_array() isn't supposed to be used by
non-PV, drop the parameter there as well. It was bogusly passed as non-
NULL (PRIV_VMA_LOCKED) by its only caller anyway. For
xen_remap_domain_gfn_range(), otoh, it's not clear at all why this
wouldn't want / might not need to gain auto-translated support down the
road, so the parameter is retained there despite now remaining unused
(and the only caller passing NULL); correct a respective comment as
well.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/036ad8a2-46f9-ac3d-6219-bdc93ab9e10b@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
xen_pfn_t is the same size as int only on 32-bit builds (and not even
on Arm32). Hence pfns[] can't be used directly to read individual error
values returned from xen_remap_domain_mfn_array(); every other error
indicator would be skipped/ignored on 64-bit.
Fixes: 3ad0876554 ("xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/aa6d6a67-6889-338a-a910-51e889f792d5@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Osstest has been suffering test failures for a little while from order-4
allocation failures, resulting from alloc_empty_pages() calling
kcalloc(). As there's no need for physically contiguous space here,
switch to kvcalloc().
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/6d698901-98a4-05be-c421-bcd0713f5335@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
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Merge tag 'for-linus-5.15b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"Some minor cleanups and fixes of some theoretical bugs, as well as a
fix of a bug introduced in 5.15-rc1"
* tag 'for-linus-5.15b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/x86: fix PV trap handling on secondary processors
xen/balloon: fix balloon kthread freezing
swiotlb-xen: this is PV-only on x86
xen/pci-swiotlb: reduce visibility of symbols
PCI: only build xen-pcifront in PV-enabled environments
swiotlb-xen: ensure to issue well-formed XENMEM_exchange requests
Xen/gntdev: don't ignore kernel unmapping error
xen/x86: drop redundant zeroing from cpu_initialize_context()
Commit 8480ed9c2b ("xen/balloon: use a kernel thread instead a
workqueue") switched the Xen balloon driver to use a kernel thread.
Unfortunately the patch omitted to call try_to_freeze() or to use
wait_event_freezable_timeout(), causing a system suspend to fail.
Fixes: 8480ed9c2b ("xen/balloon: use a kernel thread instead a workqueue")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210920100345.21939-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
The code is unreachable for HVM or PVH, and it also makes little sense
in auto-translated environments. On Arm, with
xen_{create,destroy}_contiguous_region() both being stubs, I have a hard
time seeing what good the Xen specific variant does - the generic one
ought to be fine for all purposes there. Still Arm code explicitly
references symbols here, so the code will continue to be included there.
Instead of making PCI_XEN's "select" conditional, simply drop it -
SWIOTLB_XEN will be available unconditionally in the PV case anyway, and
is - as explained above - dead code in non-PV environments.
This in turn allows dropping the stubs for
xen_{create,destroy}_contiguous_region(), the former of which was broken
anyway - it failed to set the DMA handle output.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/5947b8ae-fdc7-225c-4838-84712265fc1e@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
While the hypervisor hasn't been enforcing this, we would still better
avoid issuing requests with GFNs not aligned to the requested order.
Instead of altering the value also in the call to panic(), drop it
there for being static and hence easy to determine without being part
of the panic message.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/7b3998e3-1233-4e5a-89ec-d740e77eb166@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
While working on XSA-361 and its follow-ups, I failed to spot another
place where the kernel mapping part of an operation was not treated the
same as the user space part. Detect and propagate errors and add a 2nd
pr_debug().
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/c2513395-74dc-aea3-9192-fd265aa44e35@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
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Merge tag 'for-linus-5.15b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
- The first hunk of a Xen swiotlb fixup series fixing multiple minor
issues and doing some small cleanups
- Some further Xen related fixes avoiding WARN() splats when running as
Xen guests or dom0
- A Kconfig fix allowing the pvcalls frontend to be built as a module
* tag 'for-linus-5.15b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
swiotlb-xen: drop DEFAULT_NSLABS
swiotlb-xen: arrange to have buffer info logged
swiotlb-xen: drop leftover __ref
swiotlb-xen: limit init retries
swiotlb-xen: suppress certain init retries
swiotlb-xen: maintain slab count properly
swiotlb-xen: fix late init retry
swiotlb-xen: avoid double free
xen/pvcalls: backend can be a module
xen: fix usage of pmd_populate in mremap for pv guests
xen: reset legacy rtc flag for PV domU
PM: base: power: don't try to use non-existing RTC for storing data
xen/balloon: use a kernel thread instead a workqueue
It was introduced by 4035b43da6 ("xen-swiotlb: remove xen_set_nslabs")
and then not removed by 2d29960af0 ("swiotlb: dynamically allocate
io_tlb_default_mem").
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/15259326-209a-1d11-338c-5018dc38abe8@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
I consider it unhelpful that address and size of the buffer aren't put
in the log file; it makes diagnosing issues needlessly harder. The
majority of callers of swiotlb_init() also passes 1 for the "verbose"
parameter.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/2e3c8e68-36b2-4ae9-b829-bf7f75d39d47@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Maximilian Heyne
Oleksandr Tyshchenko
Keith Busch
Juergen Gross
Marek Marczykowski-Górecki
Dan Carpenter
Roger Pau Monne
Samuel Holland
Al Viro
Harshit Mogalapalli
ruanjinjie
Yang Yingliang
M. Vefa Bicakci
Dan Carpenter
Demi Marie Obenour
Julien Grall
Masahiro Yamada
David Stevens
Oleksandr Andrushchenko
Stefano Stabellini
YueHaibing
Linus Torvalds
Jan Beulich