xenstore-paths.markdown talked about ~/device/serial/, but that's not
used.
(It is very wrong for this value, which contains a driver domain
filesystem path, to be in the guest's area of xenstore. However, it
is only ever created by libxl and ready by xenconsoled. When it is
created, it inherits the read-only permissions of /local/domain/DOMID.
So there is no security bug.)
This is a followup to XSA-175.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
We want to stop libxl trustingly reading information from the backend
directory (since this is, of course, writeable by the backend, which
might be a semi-trusted driver domain).
In principle it is wrong in current libxl for anything to try to
divine virtual device configuration from xenstore: the JSON domain
config ought to supply that, and xenstore should only tell us which
devices actually exist.
However:
Firstly, there are several existing places where configuration
information is retrieved from xenstore rather than JSON. We do not
want to reen gineer this in a security patch.
Secondly, we want to make a security patch which can be backported to
versions of libxl without the JSON configuration machinery.
So we take the expedient approach of keeping a copy of the
configuration somewhere we trust, namely /libxl. This is obviously
fairly low-risk, although it does write significantly more keys in
xenstore.
In this patch we make this change in libxl__device_generic_add. This
is responsible for actually writing the vast majority of device
information to xenstore. There are a few loose ends which will be
dealt with in a moment.
Likewise, changes to readers to use the new location will appear in
further patches.
This is part of XSA-178.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
This gives us a record of all the backends we have set up for a
domain, which is separate from the frontends in
/local/domain/$DOMID/device.
In particular:
1. A guest has write permission for the frontend path:
/local/domain/$DOMID/device/$KIND/$DEVID
which means that the guest can completely delete the frontend.
(They can't recreate it because they don't have write permission
on the containing directory.)
2. A guest has write permission for the backend path recorded in the
frontend, ie, it can write to
/local/domain/$DOMID/device/$KIND/$DEVID/backend
which means that the guest can break the association between
frontend and backend.
So we can't rely on iterating over the frontends to find all the
backends, or examining a frontend to discover how a device is
configured.
So, have libxl__device_generic_add record the frontend and backend
paths in /libxl/$DOMID/device, and have libxl__device_destroy remove
them again.
Create the containing directory /libxl/GUEST/device in
libxl__domain_make. The already existing xs_rm in devices_destroy_cb
will take care of removing it.
This is part of XSA-175.
Backport note: Backported over 7472ced, which fixes a bug in driver
domain teardown.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
We've been told by Intel that inconsistent cachability between
multiple mappings of the same page can affect system stability only
when the affected page is an MMIO one. Since the stale data issue is
of no relevance to the hypervisor (since all guest memory accesses go
through proper accessors and validation), handling of RAM pages
remains unchanged here. Any MMIO mapped by domains however needs to be
done consistently (all cachable mappings or all uncachable ones), in
order to avoid Machine Check exceptions. Since converting existing
cachable mappings to uncachable (at the time an uncachable mapping
gets established) would in the PV case require tracking all mappings,
allow MMIO to only get mapped uncachable (UC, UC-, or WC).
This also implies that in the PV case we mustn't use the L1 PTE update
fast path when cachability flags get altered.
Since in the HVM case at least for now we want to continue honoring
pinned cachability attributes for pages not mapped by the hypervisor,
special case handling of r/o MMIO pages (forcing UC) gets added there.
Arguably the counterpart change to p2m-pt.c may not be necessary, since
UC- (which already gets enforced there) is probably strict enough.
Note that the shadow code changes include fixing the write protection
of r/o MMIO ranges: shadow_l1e_remove_flags() and its siblings, other
than l1e_remove_flags() and alike, return the new PTE (and hence
ignoring their return values makes them no-ops).
This is CVE-2016-2270 / XSA-154.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: c61a6f74f8
master date: 2016-02-17 16:16:53 +0100
Introduce and enforce separate limits for ordinary DomU, DomU with
pass-through device(s), control domain, and hardware domain.
The DomU defaults were determined based on what so far was allowed by
multipage_allocation_permitted().
The x86 hwdom default was chosen based on linux-2.6.18-xen.hg c/s
1102:82782f1361a9 indicating 2Mb is not enough, plus some slack.
The ARM hwdom default was chosen to allow 2Mb (order-9) mappings, plus
a little bit of slack.
This is CVE-2015-8338 / XSA-158.
Reported-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
master commit: 4a578b316e
master date: 2015-12-08 14:00:33 +0100
Some versions of markdown (specifically the one in Debian Wheezy, currently
used to generate
http://xenbits.xen.org/docs/unstable/misc/xen-command-line.html) seem to be
confused by nested lists in the middle of multi-paragraph parent list entries
as seen in the com1,com2 entry.
The effect is that the "Default" section of all following entries are replace
by some sort of hash or checksum (at least, a string of 32 random seeming hex
digits).
Workaround this issue by making the decriptions of the DPS options a nested
list, moving the existing nested list describing the options for S into a third
level list. This seems to avoid the issue, and is arguably better formatting in
its own right (at least its not a regression IMHO)
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit ae325e94d2)
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
For example on Dell machines we see:
(XEN) 00000fed18000-00000fed19fff type=11 attr=8000000000000000
(XEN) Unknown cachability for MFNs 0xfed18-0xfed19
Let's allow them to be mapped as UC.
We also alter the 'efi-rs' to be 'efi=rs' or 'efi=no-rs'.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
master commit: 74cdad5dae
master date: 2015-06-10 12:04:07 +0200
By default we will always use EFI reboot mechanism when
running under EFI platforms. However some EFI platforms
are buggy and need to use the ACPI mechanism to
reboot (such as Lenovo ThinkCentre M57). As such
respect the 'reboot=' override and DMI overrides
for EFI platforms.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- BOOT_INVALID is just zero
- also consider acpi_disabled in BOOT_INVALID resolution
- duplicate BOOT_INVALID resolution in machine_restart()
- don't fall back from BOOT_ACPI to BOOT_EFI (if it was overridden, it
surely was for a reason)
- adjust doc change formatting
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
x86/EFI: fix reboot after c643fb110a
acpi_disabled needs to be moved out of .init.data.
Reported-by: Ross Lagerwall <ross.lagerwall@citrix.com>
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Ross Lagerwall <ross.lagerwall@citrix.com>
master commit: c643fb110a
master date: 2015-03-13 11:25:52 +0100
master commit: 8ff330ec11
master date: 2015-03-23 18:01:51 +0100
NMI watchdog sets APIC_LVTPC register to generate an NMI when PMU counter
overflow occurs. This may be overwritten by VPMU code later, effectively
turning off the watchdog.
We should disable VPMU when NMI watchdog is running.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: e5e09b5c46
master date: 2015-02-03 11:30:09 +0100
On certain systems some of the memory map entries designated for use by
runtime services cannot be mapped (frequently due to firmware bugs). On
others, some of the memory map entries aren't even marked for runtime
services use, yet are being used by them. For both cases give people a
way to suppress use of runtime services altogether.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 5680244040
master date: 2014-10-27 16:43:52 +0100
Change NMI processing so that if watchdog=force is passed on the
command-line and the NMI is not caused by a perf counter overflow (i.e.
likely not a watchdog "tick"), the NMI is handled by the unknown NMI
handler.
This allows injection of NMIs from IPMI controllers that don't set the
IOCK/SERR bits to trigger the unknown NMI handler rather than be
ignored.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Fix command line parsing (don't enable the watchdog on e.g.
"watchdog=xyz").
Signed-off-by: Jan Beulich <jbeulich@suse.com>
x86/NMI: allow passing just "watchdog" again
This capability got inadvertently lost in commit 3ea2ba980a ("x86/NMI:
allow processing unknown NMIs when watchdog is enabled") due to an
oversight of mine.
Reported-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 3ea2ba980a
master date: 2014-08-28 16:11:37 +0200
master commit: fd553ae5f0
master date: 2014-09-03 15:09:59 +0200
Xen cannot safely use any ATS functionality until it gains asynchronous queued
invalidation support, because of the current synchronous wait for completion.
Do not turn ATS on by default.
While editing the default in the command line documentation, correct the
statement regarding PCI Passthrough. ATS is purely a performance
optimisation, and is certainly not required for PCI Passthrough to function.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
master commit: ad6eddb742
master date: 2014-08-28 16:05:10 +0200
disk=[ ' target=/dev/loop0 ' ] will fail to parse because
'/dev/loop ' does not exist.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The automatic shutdown feature of the vTPM was removed because it
interfered with pv-grub measurement support and was also not triggered
if the guest did not use the vTPM. Virtual TPM domains will need to be
shut down or destroyed on guest shutdown via a script or other user
action.
This also fixes an incorrect reference to the vTPM being PV-only.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
It is the compatible string which matters, not the absolute path, and in any
case /chosen/module@N is more often used than /chosen/modules/module@N.
Reported-by: Fu Wei <fu.wei@linaro.org>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.gral@linaro.org>
Document the event channel protocol in xenstore-paths.markdown, in the
section for ~/device/suspend/event-channel.
Protocol reverse-engineered from commentary and commit messages of
4539594d46 Add facility to get notification of domain suspend ...
17636f47a4 Teach xc_save to use event-channel-based ...
and implementations in
xc_save (current version)
libxl (current version)
linux-2.6.18-xen (mercurial 1241:2993033a77ca)
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
CC: Keir Fraser <keir@xen.org>
CC: Shriram Rajagopalan <rshriram@cs.ubc.ca>
List all the sub ops of:
__HYPERVISOR_domctl
__HYPERVISOR_sysctl
__HYPERVISOR_memory_op
__HYPERVISOR_tmem_op
which are subject to the policy given in
http://xenbits.xen.org/xsa/advisory-77.html
It is expected that these lists will be whittled away as each interface is
audited for safety.
New interfaces should be expected to be safe when introduced (IOW the list
should never be expanded).
This is XSA-77.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
This patch adds a short description of xen-pvdevice to
pci-device-reservations.txt, which contains the canonical list
of device IDs that may be used to create xen-pvdevice instances.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- ran expand to de-tabbify ]
If libxl is executed inside a guest domain it needs write access to
the local libxl xenstore dir (/local/<domid>/libxl) to store internal
data. This also applies to Qemu which needs a
/local/<domid>/device-model xenstore directory.
This patch creates the mentioned directories for each guest launched
from libxl.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Introduce the %ps and %pS format options for printing a symbol.
%ps will print the symbol name and optional offset and size
%pS will print the symbol name and unconditional offset and size
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
The chosen node's bootargs property should be used for Xen if there is a dom0
kernel multiboot module with a command line, not just if xen,dom0-bootargs is
present.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.linaro.org>
The Linux kernel is able to update the microcode during early bootup
via inspection of the initramfs blob to see if there is an cpio image
with certain microcode files. Linux is able to function with two (or
more) cpio archives in the initrd b/c it unpacks all of the cpio
archives.
The format of the early initramfs is nicely documented in Linux's
Documentation/x86/early-microcode.txt:
Early load microcode
====================
By Fenghua Yu <fenghua.yu@intel.com>
Kernel can update microcode in early phase of boot time. Loading microcode early
can fix CPU issues before they are observed during kernel boot time.
Microcode is stored in an initrd file. The microcode is read from the initrd
file and loaded to CPUs during boot time.
The format of the combined initrd image is microcode in cpio format followed by
the initrd image (maybe compressed). Kernel parses the combined initrd image
during boot time. The microcode file in cpio name space is:
kernel/x86/microcode/GenuineIntel.bin
During BSP boot (before SMP starts), if the kernel finds the microcode file in
the initrd file, it parses the microcode and saves matching microcode in memory.
If matching microcode is found, it will be uploaded in BSP and later on in all
APs.
The cached microcode patch is applied when CPUs resume from a sleep state.
There are two legacy user space interfaces to load microcode, either through
/dev/cpu/microcode or through /sys/devices/system/cpu/microcode/reload file
in sysfs.
In addition to these two legacy methods, the early loading method described
here is the third method with which microcode can be uploaded to a system's
CPUs.
The following example script shows how to generate a new combined initrd file in
/boot/initrd-3.5.0.ucode.img with original microcode microcode.bin and
original initrd image /boot/initrd-3.5.0.img.
mkdir initrd
cd initrd
mkdir kernel
mkdir kernel/x86
mkdir kernel/x86/microcode
cp ../microcode.bin kernel/x86/microcode/GenuineIntel.bin
find .|cpio -oc >../ucode.cpio
cd ..
cat ucode.cpio /boot/initrd-3.5.0.img >/boot/initrd-3.5.0.ucode.img
As such this code inspects the initrd to see if the microcode
signatures are present and if so updates the hypervisor.
The option to turn this scan on/off is gated by the 'ucode'
parameter. The options are now:
'scan' Scan for the microcode in any multiboot payload.
<index> Attempt to load microcode blob (not the cpio archive
format) from the multiboot payload number.
This option alters slightly the 'ucode' parameter by only allowing
either parameter:
ucode=[<index>|scan]
Implementation wise the ucode_blob is defined as __initdata.
That is OK from the viewpoint of suspend/resume as the the underlaying
architecture microcode (microcode_intel or microcode_amd) end up saving
the blob in 'struct ucode_cpu_info' which is a per-cpu data
structure (see ucode_cpu_info). They end up saving it when doing the
pre-SMP (for CPU0) and SMP (for the rest) microcode loading.
Naturally if one does a hypercall to update the microcode and it is
newer, then the old per-cpu data is replaced.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Keir Fraser <keir@xen.org>
Currently we use the chosen/bootargs property as the Xen commandline
and rely on xen,dom0-bootargs for Dom0. However this brings issues
with bootloaders, which usually build bootargs by bootscripts for a
Linux kernel - and not for the entirely different Xen hypervisor.
Introduce a new possible device tree property "xen,xen-bootargs"
explicitly for the Xen hypervisor and make the selection of which to
use more fine grained:
- If xen,xen-bootargs is present, it will be used for Xen.
- If xen,dom0-bootargs is present, it will be used for Dom0.
- If xen,xen-bootargs is _not_ present, but xen,dom0-bootargs is,
bootargs will be used for Xen. Like the current situation.
- If no Xen specific properties are present, bootargs is for Dom0.
- If xen,xen-bootargs is present, but xen,dom0-bootargs is missing,
bootargs will be used for Dom0.
The aim is to allow common bootscripts to boot both Xen and native
Linux with the same device tree blob. If needed, one could hard-code
the Xen commandline into the DTB, leaving bootargs for Dom0 to be set
by the (non Xen-aware) bootloader.
I will send out a appropriate u-boot patch, which writes the content
of the "xen_bootargs" environment variable into the xen,xen-bootargs
dtb property.
Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The BIOS reboot option was never implemented for x86_64, and retaining
it is somewhat false advertising.
Signed-off-by: Matt Wilson <msw@amazon.com>
Acked-by: Keir Fraser <keir@xen.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
With there being so many systems with broken ACPI tables, and with it
generally being known what's wrong with those tables, give people a
handle to overcome the resulting disabling of their IOMMUs.
Inspired by Linux side patches providing similar functionality.
Suggested-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-By: Sander Eikelenboom <linux@eikelenboom.it>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Suravee Suthikulpanit <suravee.suthikulapanit@amd.com>
The Cyclone time source was part of IBM's Summit chipset, which was
only used for 32-bit only ccNUMA and IA-64 machines. Neither of these
are supported by Xen anymore.
Signed-off-by: Matt Wilson <msw@amazon.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
IBM's Summit chipset was only used for 32-bit only Intel ccNUMA and
IA-64 machines, neither of which are supported by Xen anymore.
Signed-off-by: Matt Wilson <msw@amazon.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Both OMAP5 and sun6i/sun7i SoCs share this UART driver for early_printk.
Signed-off-by: Chen Baozi <baozich@gmail.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
This patch introduces a documentation file to record reservations of
ranges of PCI device IDs within the Xen vendor ID 0x5853.
Signed-off-by: James Bulpin <james.bulpin@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
With the help of the previous patches add a stanza to
xen/arch/arm/Rules.mk to specify the UART configuration of the
Calxeda Midway machine.
The information has been taken from the Linux kernel's .dts file.
This can be enabled by adding "CONFIG_EARLY_PRINTK=midway" to
Config.mk.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Though the ARM Fastmodel software emulator mimics a Versatile Express
board, the boot process is different compared to the real hardware,
so the early printk differs slightly. Create a new early-printk
target to model this correctly.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The UART memory mapped base address is currently hardcoded in the
early-printk UART driver, which denies the driver to be used by
two machines with a different mapping.
Move this definition out to xen/arch/arm/Rules.mk, allowing easier
user access and later sharing of the driver.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
While it seems obvious to initialize the UART before using it, chances
are that some firmware code or the bootloader already did this.
So it may actually be a good idea to skip the initialization, in fact
this fixes early printk on my TC2 Versatile Express.
So provide an option in xen/arch/arm/Rules.mk to only initialize the
UART when needed.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
For early-printk the used baud rate was hardcoded in the code, using
precalculated divisor values.
Let the calculation of these values be done by the preprocessor and
use a human readable value in xen/arch/arm/Rules.mk to drive this.
Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Add CONFIG_EARLY_PRINTK options in configs/arm{32,64}.mk to let the user
to choose if he wants to have early output, ie before the console is initialized.
This code is specific for each UART. When CONFIG_EARLY_PRINTK is enabled,
Xen will only be able to run on a board with this UART.
If a developper wants to add support for a new UART, he must implement the
following assembly macro/define:
- EALY_UART_BASE_ADDRESS: variable which contains the physical base address
for the UART
- early_uart_init: initialize the UART
- early_uart_ready: check and wait until the UART can transmit a new
character
- early_uart_transmit: transmit a character
For more details about the parameters of each function,
see arm{32,64}/debug-pl011.inc comments.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
This adds a backend_domname field in libxl devices that contain a
backend_domid field, allowing either a domid or a domain name to be
specified in the configuration structures. The domain name is resolved
into a domain ID in the _setdefault function when adding the device.
This change allows the backend of the block devices to be specified
(which previously required passing the libxl_ctx down into the block
device parser), and will simplify specification of backend domains in
other users of libxl.
The check on run_hotplug_scripts in parse_config_data is removed because
it is a duplicate of the one in libxl__device_nic_setdefault, and is
removed here because it no longer has the resolved domain ID to check.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- reran flex ]