Xen-pciback driver was designed to be built for x86 only. But it
can also be used by other architectures, e.g. Arm.
Currently PCI backend implements multiple functionalities at a time,
such as:
1. It is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever
the toolstack needs to know which PCI devices can be passed through
it reads that from the relevant sysfs entries of the pciback.
2. It is used to hold the unbound PCI devices list, e.g. when passing
through a PCI device it needs to be unbound from the relevant device
driver and bound to pciback (strictly speaking it is not required
that the device is bound to pciback, but pciback is again used as a
database of the passed through PCI devices, so we can re-bind the
devices back to their original drivers when guest domain shuts down)
3. Device reset for the devices being passed through
4. Para-virtualised use-cases support
The para-virtualised part of the driver is not always needed as some
architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend
model for PCI device passthrough.
For such use-cases make the very first step in splitting the
xen-pciback driver into two parts: Xen PCI stub and PCI PV backend
drivers.
For that add new configuration options CONFIG_XEN_PCI_STUB and
CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its
functionality, e.g. no support for para-virtualised scenario.
x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the
fully featured backend driver.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20211028143620.144936-1-andr2000@gmail.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Information printed under verbose_request is clearly used for debugging
only. Remove it and use dev_dbg() instead.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/1590719092-8578-1-git-send-email-boris.ostrovsky@oracle.com
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Use dev_printk() when possible to include device and driver information in
the conventional format.
Add "#define dev_fmt" when needed to preserve DRV_NAME or KBUILD_MODNAME in
messages.
No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20200527174326.254329-2-helgaas@kernel.org
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
QEMU running in a stubdom needs to be able to set INTX_DISABLE, and the
MSI(-X) enable flags in the PCI config space. This adds an attribute
'allow_interrupt_control' which when set for a PCI device allows writes
to this flag(s). The toolstack will need to set this for stubdoms.
When enabled, guest (stubdomain) will be allowed to set relevant enable
flags, but only one at a time - i.e. it refuses to enable more than one
of INTx, MSI, MSI-X at a time.
This functionality is needed only for config space access done by device
model (stubdomain) serving a HVM with the actual PCI device. It is not
necessary and unsafe to enable direct access to those bits for PV domain
with the device attached. For PV domains, there are separate protocol
messages (XEN_PCI_OP_{enable,disable}_{msi,msix}) for this purpose.
Those ops in addition to setting enable bits, also configure MSI(-X) in
dom0 kernel - which is undesirable for PCI passthrough to HVM guests.
This should not introduce any new security issues since a malicious
guest (or stubdom) can already generate MSIs through other ways, see
[1] page 8. Additionally, when qemu runs in dom0, it already have direct
access to those bits.
This is the second iteration of this feature. First was proposed as a
direct Xen interface through a new hypercall, but ultimately it was
rejected by the maintainer, because of mixing pciback and hypercalls for
PCI config space access isn't a good design. Full discussion at [2].
[1]: https://invisiblethingslab.com/resources/2011/Software%20Attacks%20on%20Intel%20VT-d.pdf
[2]: https://xen.markmail.org/thread/smpgpws4umdzizze
[part of the commit message and sysfs handling]
Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
[the rest]
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
[boris: A few small changes suggested by Roger, some formatting changes]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Just like done in d2bd05d88d ("xen-pciback: return proper values during
BAR sizing") for the ROM BAR, ordinary ones also shouldn't compare the
written value directly against ~0, but consider the r/o bits at the
bottom (if any).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Other than for raw BAR values, flags are properly separated in the
internal representation.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reads following writes with all address bits set to 1 should return all
changeable address bits as one, not the BAR size (nor, as was the case
for the upper half of 64-bit BARs, the high half of the region's end
address). Presumably this didn't cause any problems so far because
consumers use the value to calculate the size (usually via val & -val),
and do nothing else with it.
But also consider the exception here: Unimplemented BARs should always
return all zeroes.
And finally, the check for whether to return the sizing address on read
for the ROM BAR should ignore all non-address bits, not just the ROM
Enable one.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
The variable for the 'permissive' module parameter used to be static
but was recently changed to be extern. This puts it in the kernel
global namespace if the driver is built-in, so its name should begin
with a prefix identifying the driver.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: af6fc858a3 ("xen-pciback: limit guest control of command register")
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
It's not clear to me why only the enabling operation got handled so
far.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Otherwise the guest can abuse that control to cause e.g. PCIe
Unsupported Request responses by disabling memory and/or I/O decoding
and subsequently causing (CPU side) accesses to the respective address
ranges, which (depending on system configuration) may be fatal to the
host.
Note that to alter any of the bits collected together as
PCI_COMMAND_GUEST permissive mode is now required to be enabled
globally or on the specific device.
This is CVE-2015-2150 / XSA-120.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Convert printks to pr_<level> (excludes printk(KERN_DEBUG...)
to be more consistent throughout the xen subsystem.
Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_MODNAME
Coalesce formats and add missing word spaces
Add missing newlines
Align arguments and reflow to 80 columns
Remove DRV_NAME from formats as pr_fmt adds the same content
This does change some of the prefixes of these messages
but it also does make them more consistent.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This is a minor bugfix and a set of small cleanups; as it is not clear
whether this needs splitting into pieces (and if so, at what
granularity), it is a single combined patch.
- add a missing return statement to an error path in
kill_domain_by_device()
- use pci_is_enabled() rather than raw atomic_read()
- remove a bogus attempt to zero-terminate an already zero-terminated
string
- #define DRV_NAME once uniformly in the shared local header
- make DRIVER_ATTR() variables static
- eliminate a pointless use of list_for_each_entry_safe()
- add MODULE_ALIAS()
- a little bit of constification
- adjust a few messages
- remove stray semicolons from inline function definitions
Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v1: Dropped the resource_size fix, altered the description]
[v2: Fixed cleanpatch.pl comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Use resource_size function on resource object
instead of explicit computation.
The semantic patch that makes this output is available
in scripts/coccinelle/api/resource_size.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- Remove the slot and controller controller backend as they
are not used.
- Document the find pciback_[read|write]_config_[byte|word|dword]
to make it easier to find.
- Collapse the code from conf_space_capability_msi into pciback_ops.c
- Collapse conf_space_capability_[pm|vpd].c in conf_space_capability.c
[and remove the conf_space_capability.h file]
- Rename all visible functions from pciback to xen_pcibk.
- Rename all the printk/pr_info, etc that use the "pciback" to say
"xen-pciback".
- Convert functions that are not referenced outside the code to be
static to save on name space.
- Do the same thing for structures that are internal to the driver.
- Run checkpatch.pl after the renames and fixup its warnings and
fix any compile errors caused by the variable rename
- Cleanup any structs that checkpath.pl commented about or just
look odd.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If the device that is to be shared with a guest is a level device and
the IRQ is shared with the initial domain we need to take actions.
Mainly we install a dummy IRQ handler that will ACK on the interrupt
line so as to not have the initial domain disable the interrupt line.
This dummy IRQ handler is not enabled when the device MSI/MSI-X lines
are set, nor for edge interrupts. And also not for level interrupts
that are not shared amongst devices. Lastly, if the user passes
to the guest all of the PCI devices on the shared line the we won't
install the dummy handler either.
There is also SysFS instrumentation to check its state and turn
IRQ ACKing on/off if necessary.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
These changes are for PV guest to use Virtual Function. Because the VF's
vendor, device registers in cfg space are 0xffff, which are invalid and
ignored by PCI device scan. Values in 'struct pci_dev' are fixed up by
SR-IOV code, and using these values will present correct VID and DID to
PV guest kernel.
And command registers in the cfg space are read only 0, which means we
have to emulate MMIO enable bit (VF only uses MMIO resource) so PV
kernel can work properly.
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Checkpatch found some extra warnings and errors. This mega
patch fixes them all in one big swoop. We also spruce
up the pcistub_ids to use DEFINE_PCI_DEVICE_TABLE macro
(suggested by Jan Beulich).
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This is the host side counterpart to the frontend driver in
drivers/pci/xen-pcifront.c. The PV protocol is also implemented by
frontend drivers in other OSes too, such as the BSDs.
The PV protocol is rather simple. There is page shared with the guest,
which has the 'struct xen_pci_sharedinfo' embossed in it. The backend
has a thread that is kicked every-time the structure is changed and
based on the operation field it performs specific tasks:
XEN_PCI_OP_conf_[read|write]:
Read/Write 0xCF8/0xCFC filtered data. (conf_space*.c)
Based on which field is probed, we either enable/disable the PCI
device, change power state, read VPD, etc. The major goal of this
call is to provide a Physical IRQ (PIRQ) to the guest.
The PIRQ is Xen hypervisor global IRQ value irrespective of the IRQ
is tied in to the IO-APIC, or is a vector. For GSI type
interrupts, the PIRQ==GSI holds. For MSI/MSI-X the
PIRQ value != Linux IRQ number (thought PIRQ==vector).
Please note, that with Xen, all interrupts (except those level shared ones)
are injected directly to the guest - there is no host interaction.
XEN_PCI_OP_[enable|disable]_msi[|x] (pciback_ops.c)
Enables/disables the MSI/MSI-X capability of the device. These operations
setup the MSI/MSI-X vectors for the guest and pass them to the frontend.
When the device is activated, the interrupts are directly injected in the
guest without involving the host.
XEN_PCI_OP_aer_[detected|resume|mmio|slotreset]: In case of failure,
perform the appropriate AER commands on the guest. Right now that is
a cop-out - we just kill the guest.
Besides implementing those commands, it can also
- hide a PCI device from the host. When booting up, the user can specify
xen-pciback.hide=(1:0:0)(BDF..) so that host does not try to use the
device.
The driver was lifted from linux-2.6.18.hg tree and fixed up
so that it could compile under v3.0. Per suggestion from Jesse Barnes
moved the driver to drivers/xen/xen-pciback.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
