When multiple devices share resources and one of them is to be passed
through to a guest, security of the entire system and of respective
guests individually cannot really be guaranteed without knowing
internals of any of the involved guests. Therefore such a configuration
cannot really be security-supported, yet making that explicit was so far
missing.
This is XSA-461 / CVE-2024-31146.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
master commit: 9c94eda1e3
master date: 2024-08-13 16:37:25 +0200
Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence of a
store-exclusive or read of PAR_EL1 and a load with device or non-cacheable
memory attributes.
A workaround is available, but it depends on a firmware counterpart.
The proposed workaround from the errata document is to modify the software
running at EL1 and above to include a DMB SY before and after accessing
PAR_EL1.
In conjunction to the above, the firmware needs to use a specific write
sequence to several IMPLEMENTATION DEFINED registers to have the hardware
insert a DMB SY after all load-exclusive and store-exclusive instructions.
Apply the workaround to Xen where PAR_EL1 is read, implementing an helper
function to do that.
Since Xen can be interrupted by irqs in any moment, add a barrier on
entry/exit when we are running on the affected cores.
A guest without the workaround can deadlock the system, so warn the users
of Xen with the above type of cores to use only trusted guests, by
printing a message on Xen startup.
This is XSA-436 / CVE-2023-34320.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
[stefano: add XSA-436 to commit message]
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add a support statement for the scope of support regarding different
Xenstore variants. Especially oxenstored does not (yet) have security
support of untrusted driver domains, as those might drive oxenstored
out of memory by creating lots of watch events for the guests they are
servicing.
Add a statement regarding Live Update support of oxenstored.
This is part of XSA-326.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit c7bc20d8d1)
Add parameter vpmu to xl domain configuration syntax
to enable the access to PMU registers by disabling
the PMU traps(currently only for ARM).
The current status is that the PMU registers are not
virtualized and the physical registers are directly
accessible when this parameter is enabled. There is no
interrupt support and Xen will not save/restore the
register values on context switches.
According to Arm Arm, section D7.1:
"The Performance Monitors Extension is common
to AArch64 operation and AArch32 operation."
That means we have an ensurance that if PMU is
present in one exception state, it must also be
present in the other.
Please note that this feature is experimental.
Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Signed-off-by: Julien Grall <julien@xen.org>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
The support status of 32-bit guests doesn't seem particularly useful.
With it changed to fully unsupported outside of PV-shim, adjust the PV32
Kconfig default accordingly.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
We shouldn't default to include any unsupported code in the shim. Mark
the setting as off, replacing the ARGO specification. This points out
anomalies with the scheduler configuration: Unsupported schedulers
better don't default to Y in release builds (like is already the case
for ARINC653). Without at least the SCHED_NULL adjustments, the shim
would suddenly build with RTDS as its default scheduler.
As a result, the SCHED_NULL setting can also be dropped from defconfig.
Clearly with the shim defaulting to it, SCHED_NULL must be supported at
least there.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
Support to liveupdate C/OCaml xenstored daemon was added during the
4.15 development cycle. Add two new sections in SUPPORT.MD to explain
what is the support state.
For now, it is a tech preview.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
This wasn't meant to be supported, but wasn't stated this way.
This is XSA-363.
Reported-by: Jan Belich <jbeulich@suse.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
The purpose of this patch is to add a possibility for user
to be able to select IOREQ support on Arm (which is disabled
by default) with retaining the current behaviour on x86
(is selected by HVM and it's prompt is not visible).
Also make the IOREQ be depended on CONFIG_EXPERT on Arm since
it is considered as Technological Preview feature and
update SUPPORT.md.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Add support for ARM architected SMMUv3 implementation. It is based on
the Linux SMMUv3 driver.
Driver is currently supported as Tech Preview.
Major differences with regard to Linux driver are as follows:
2. Only Stage-2 translation is supported as compared to the Linux driver
that supports both Stage-1 and Stage-2 translations.
3. Use P2M page table instead of creating one as SMMUv3 has the
capability to share the page tables with the CPU.
4. Tasklets are used in place of threaded IRQ's in Linux for event queue
and priority queue IRQ handling.
5. Latest version of the Linux SMMUv3 code implements the commands queue
access functions based on atomic operations implemented in Linux.
Atomic functions used by the commands queue access functions are not
implemented in XEN therefore we decided to port the earlier version
of the code. Atomic operations are introduced to fix the bottleneck
of the SMMU command queue insertion operation. A new algorithm for
inserting commands into the queue is introduced, which is lock-free
on the fast-path.
Consequence of reverting the patch is that the command queue
insertion will be slow for large systems as spinlock will be used to
serializes accesses from all CPUs to the single queue supported by
the hardware. Once the proper atomic operations will be available in
XEN the driver can be updated.
6. Spin lock is used in place of mutex when attaching a device to the
SMMU, as there is no blocking locks implementation available in XEN.
This might introduce latency in XEN. Need to investigate before
driver is out for tech preview.
7. PCI ATS functionality is not supported, as there is no support
available in XEN to test the functionality. Code is not tested and
compiled. Code is guarded by the flag CONFIG_PCI_ATS.
8. MSI interrupts are not supported as there is no support available in
XEN to request MSI interrupts. Code is not tested and compiled. Code
is guarded by the flag CONFIG_MSI.
Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
While investigating XSA-335 we discovered that many upstream security
fixes were missing. It is not practical to backport them. There is
no good reason to be running this very ancient version of qemu, except
that it is the only way to run a stub dm which is currently supported
by upstream.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
When a Cortex A57 processor is affected by CPU errata 832075, a guest
not implementing the workaround for it could deadlock the system.
Add a warning during boot informing the user that only trusted guests
should be executed on the system.
An equivalent warning is already given to the user by KVM on cores
affected by this errata.
Also taint the hypervisor as unsecure when this errata applies and
mention Cortex A57 r0p0 - r1p2 as not security supported in SUPPORT.md
Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
[fix SUPPORT.md style, 3 printk lines instead of 4]
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
SMMUv{1, 2} are both marked as security supported, so we would
technically have to issue an XSA for any IOMMU security bug.
However, at the moment, device passthrough is not security supported
on Arm and there is no plan to change that in the next few months.
Therefore, mark Arm SMMUv{1, 2} as supported but not security supported.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Mark Renesas IPMMU-VMSA as "Supported, not security supported"
and remove dependencies on CONFIG_EXPERT.
We can't treat the IOMMU driver as "Supported" since the device
passthrough feature is not security supported on Arm today.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Add a README and package comment giving a brief overview of the package.
These also help pkg.go.dev generate better documentation.
Also, add a copy of the LGPL (the same license used by libxl) to
tools/golang/xenlight. This is required for the package to be shown
on pkg.go.dev and added to the default module proxy, proxy.golang.org.
Finally, add an entry for the xenlight package to SUPPORT.md.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Change the url scheme to https. This is all in-tree references to
xenbits and the main website except for those in Config.mk.
We leave Config.mk alone for now because those urls are used by CI
systems and we need to check that nothing breaks when we change the
download method.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Renesas IPMMU-VMSA support (Arm) can be considered
as Technological Preview feature.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
With the latest patches to the mediator, it can be considered
as Technological Preview feature.
Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Julien Grall <julien.grall@arm.com>
In order to have a link to the release notes in the feature list
generated from SUPPORT.md add that link in the "Release Support"
section of that file.
The real link needs to be adapted when the version is being released.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
This turns all the things which were treated as caveats, but which
don't need to be footnoted in the matrix, into descriptions.
For the benefit of the support matrix generator, this patch (or a
version of it) should be backported to 4.10.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
This commits (more or less) this file to be processed with pandoc,
rather than other markdown processors. There is, unfortunately, no
widely-accepted way to declare a title for the document.
I tested feeding the document to markdown(1) on Debian jessie and it
reproduced the % line as if it were simple text. I guess many other
markdown processors will do something similarly tolerable. My
internet searches did not discover a markdown processor that used
lines starting with % for something else.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Lars Kurth <lars.kurth@citrix.com>
Continuations of bullet list items must be indented by exactly 4
spaces (according to pandoc_markdown(5) on Debian jessie).
This is most easily achieved by making the bullet list items have two
spaces before the `*'.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Lars Kurth <lars.kurth@citrix.com>
Also fix x86/HVM to spell out that only DomU HVM mode is supported and
remove the 'guest' from the ARM section, ARM supports both Dom0/DomU
using the same mode.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
The code has been there in the hypervisor for several releases, but
there is no toolstack support.
While we're here delete some trailing whitespace.
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Jan Beulich