This commit sets/tearsdown of p2m pages pool for non-privileged Arm
guests by calling `p2m_set_allocation` and `p2m_teardown_allocation`.
- For dom0, P2M pages should come from heap directly instead of p2m
pool, so that the kernel may take advantage of the extended regions.
- For xl guests, the setting of the p2m pool is called in
`XEN_DOMCTL_shadow_op` and the p2m pool is destroyed in
`domain_relinquish_resources`. Note that domctl->u.shadow_op.mb is
updated with the new size when setting the p2m pool.
- For dom0less domUs, the setting of the p2m pool is called before
allocating memory during domain creation. Users can specify the p2m
pool size by `xen,domain-p2m-mem-mb` dts property.
To actually allocate/free pages from the p2m pool, this commit adds
two helper functions namely `p2m_alloc_page` and `p2m_free_page` to
`struct p2m_domain`. By replacing the `alloc_domheap_page` and
`free_domheap_page` with these two helper functions, p2m pages can
be added/removed from the list of p2m pool rather than from the heap.
Since page from `p2m_alloc_page` is cleaned, take the opportunity
to remove the redundant `clean_page` in `p2m_create_table`.
This is part of CVE-2022-33747 / XSA-409.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
That's possible, because the capability was designed specifically to
allow separate driver handle it, in parallel to unmodified xhci driver
(separate set of registers, pretending the port is "disconnected" for
the main xhci driver etc). It works with Linux dom0, although requires
an awful hack - re-enabling bus mastering behind dom0's backs.
Linux driver does similar thing - see
drivers/usb/early/xhci-dbc.c:xdbc_handle_events().
When controller sharing is enabled in kconfig (option marked as
experimental), dom0 is allowed to use the controller even if Xen uses it
for debug console. Additionally, option `dbgp=xhci,share=` is available
to either prevent even dom0 from using it (`no` value), or allow any
domain using it (`any` value).
In any case, to avoid Linux messing with the DbC, mark this MMIO area as
read-only. This might cause issues for Linux's driver (if it tries to
write something on the same page - like anoter xcap), but makes Xen's
use safe. In practice, as of Linux 5.18, it seems to work without
issues.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add another work ring buffer for received data, and point IN TRB at it.
Ensure there is always at least one pending IN TRB, so the controller
has a way to send incoming data to the driver.
Note that both "success" and "short packet" completion codes are okay -
in fact it will be "short packet" most of the time, as the TRB length is
about maximum size, not required size.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
This allows configuring EHCI and XHCI consoles separately,
simultaneously, such that e.g. one can be used for the console and the
other by the debugger.
This changes string_param() to custom_param() in both ehci and xhci
drivers. Both drivers parse only values applicable to them.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
In order to keep consistency in the device tree binding, there is
no need for static memory allocation feature to define a specific
set of address and size cells for "xen,static-mem" property.
Therefore, this commit reuses the regular #{address,size}-cells
for parsing the device tree "xen,static-mem" property. Update
the documentation accordingly.
Also, take the chance to remove the unnecessary "#address-cells"
and "#size-cells" in the domU1 node of the device tree to only
emphasize the related part that the example is showing.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
This patch series introduces a new feature: setting up static
shared memory on a dom0less system, through device tree configuration.
This commit parses shared memory node at boot-time, and reserve it in
bootinfo.reserved_mem to avoid other use.
This commits proposes a new Kconfig CONFIG_STATIC_SHM to wrap
static-shm-related codes, and this option depends on static memory(
CONFIG_STATIC_MEMORY). That's because that later we want to reuse a few
helpers, guarded with CONFIG_STATIC_MEMORY, like acquire_staticmem_pages, etc,
on static shared memory.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The static-heap dt-binding should be placed after the last feature,
namely static-evtchn.
Fixes: 4596329291 ("docs, xen/arm: Introduce static heap memory")
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
This commit introduces the static heap memory, which is parts of RAM
reserved in the beginning of the boot time for heap.
Firstly, since a new type of memory bank is needed for marking the
memory bank solely as the heap, this commit defines `enum membank_type`
and use this enum in function device_tree_get_meminfo(). Changes of
code are done accordingly following the introduction of this enum.
Also, this commit introduces the logic to parse the static heap
configuration in device tree. If the memory bank is reserved as heap
through `xen,static-heap` property in device tree `chosen` node, the
memory will be marked as static heap type.
A documentation section is added, describing the definition of static
heap memory and the method of enabling the static heap memory through
device tree at boot time.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Introduce a new sub-node under /chosen node to establish static event
channel communication between domains on dom0less systems.
An event channel will be created beforehand to allow the domains to
send notifications to each other.
Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Introduce a new "xen,enhanced" dom0less property value "no-xenstore" to
disable xenstore interface for dom0less guests.
Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add documentation for an extension of the WATCH command used to limit
the scope of watched paths. Additionally it enables to receive more
information in the events related to special watches (@introduceDomain
or @releaseDomain).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add documentation for two new Xenstore wire commands SET_QUOTA and
GET_QUOTA used to set or query the global Xenstore quota or those of
a given domain.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Handle parameters similar to dbgp=ehci.
Implement this by not resettting dbc->sbdf again in dbc_init_xhc(), but
using a value found there if non-zero. Additionally, add xue->xhc_num to
select n-th controller.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
[Connor]
Xue is a cross-platform USB 3 debugger that drives the Debug
Capability (DbC) of xHCI-compliant host controllers. This patch
implements the operations needed for xue to initialize the host
controller's DbC and communicate with it. It also implements a struct
uart_driver that uses xue as a backend. Note that only target -> host
communication is supported for now. To use Xue as a console, add
'console=dbgp dbgp=xhci' to the command line.
[Marek]
The Xue driver is taken from https://github.com/connojd/xue and heavily
refactored to fit into Xen code base. Major changes include:
- rename to xhci_dbc
- drop support for non-Xen systems
- drop xue_ops abstraction
- use Xen's native helper functions for PCI access
- move all the code to xue.c, drop "inline"
- build for x86 only
- annotate functions with cf_check
- adjust for Xen's code style
At this stage, only the first xHCI is considered, and only output is
supported. Later patches add support for choosing specific device, and
input handling.
The driver is initiallized before memory allocator works, so all the
transfer buffers (about 230KiB of them) are allocated statically and will
use memory even if XUE console is not selected. The driver can be
disabled build time to reclaim this memory.
Most of this memory is shared with the controller via DMA. Later patch
will adjust structures placement to avoid anything else to be placed on
those DMA-reachable pages. This also means str_buf cannot use static
initializer, without reserving (at least) a whole page page in .data (or
more, when combined with other structures).
Signed-off-by: Connor Davis <davisc@ainfosec.com>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Not even the types were correct, let alone defaults being spelled out or
the purpose of the options actually mentioned in any way.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Add documentation for two new Xenstore wire commands SET_FEATURE and
GET_FEATURE used to set or query the Xenstore features visible in the
ring page of a given domain.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Before actually enabling their use, provide a means to suppress it in
case of problems. Note that using the option can also affect the sharing
of page tables in the VT-d / EPT combination: If EPT would use large
page mappings but the option is in effect, page table sharing would be
suppressed (to properly fulfill the admin request).
Requested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Paul Durrant <paul@xen.org>
With debug info retained, xen.efi can be quite large. Unlike for xen.gz
there's no intermediate step (mkelf32 there) involved which would strip
debug info kind of as a side effect. While the installing of xen.efi on
the EFI partition is an optional step (intended to be a courtesy to the
developer), adjust it also for the purpose of documenting what distros
would be expected to do during boot loader configuration (which is what
would normally put xen.efi into the EFI partition).
Model the control over stripping after Linux'es module installation,
except that the stripped executable is constructed in the build area
instead of in the destination location. This is to conserve on space
used there - EFI partitions tend to be only a few hundred Mb in size.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Henry Wang <Henry.Wang@arm.com>
Tested-by: Wei Chen <Wei.Chen@arm.com> # arm
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Add documentation for an extension of the WATCH command used to limit
the scope of watched paths. Additionally it enables to receive more
information in the events related to special watches (@introduceDomain
or @releaseDomain).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Add documentation for two new Xenstore wire commands SET_QUOTA and
GET_QUOTA used to set or query the Xenstore quota of a given domain.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Add documentation for two new Xenstore wire commands SET_FEATURE and
GET_FEATURE used to set or query the Xenstore features visible in the
ring page of a given domain.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Branch Type Confusion affects AMD/Hygon CPUs on Zen2 and earlier. To
mitigate, we require SMT safety (STIBP on Zen2, no-SMT on Zen1), and to issue
an IBPB on each entry to Xen, to flush the BTB.
Due to performance concerns, dom0 (which is trusted in most configurations) is
excluded from protections by default.
Therefore:
* Use STIBP by default on Zen2 too, which now means we want it on by default
on all hardware supporting STIBP.
* Break the current IBPB logic out into a new function, extending it with
IBPB-at-entry logic.
* Change the existing IBPB-at-ctxt-switch boolean to be tristate, and disable
it by default when IBPB-at-entry is providing sufficient safety.
If all PV guests on the system are trusted, then it is recommended to boot
with `spec-ctrl=ibpb-entry=no-pv`, as this will provide an additional marginal
perf improvement.
This is part of XSA-407 / CVE-2022-23825.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Support controling the PV/HVM suboption of msr-sc/rsb/md-clear, which
previously wasn't possible.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
STIBP and PSFD are slightly weird bits, because they're both implied by other
bits in MSR_SPEC_CTRL. Add fine grain controls for them, and take the
implications into account when setting IBRS/SSBD.
Rearrange the IBPB text/variables/logic to keep all the MSR_SPEC_CTRL bits
together, for consistency.
However, AMD have a hardware hint CPUID bit recommending that STIBP be set
unilaterally. This is advertised on Zen3, so follow the recommendation.
Furthermore, in such cases, set STIBP behind the guest's back for now. This
has negligible overhead for the guest, but saves a WRMSR on vmentry. This is
the only default change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Instead of specifying the feature bits in xenstore-ring.txt as a mask
value use bit numbers. This will make the specification easier to read
when adding more features.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Per Xen's support statement, PCI passthrough should be to trusted domains
because the overall system security depends on factors outside of Xen's
control.
As such, Xen, in a supported configuration, is not vulnerable to DRPW/SBDR.
However, users who have risk assessed their configuration may be happy with
the risk of DoS, but unhappy with the risk of cross-domain data leakage. Such
users should enable this option.
On CPUs vulnerable to MDS, the existing mitigations are the best we can do to
mitigate MMIO cross-domain data leakage.
On CPUs fixed to MDS but vulnerable MMIO stale data leakage, this option:
* On CPUs susceptible to FBSDP, mitigates cross-domain fill buffer leakage
using FB_CLEAR.
* On CPUs susceptible to SBDR, mitigates RNG data recovery by engaging the
srb-lock, previously used to mitigate SRBDS.
Both mitigations require microcode from IPU 2022.1, May 2022.
This is part of XSA-404.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Currently, VERW flushing to mitigate MDS is boot time conditional per domain
type. However, to provide mitigations for DRPW (CVE-2022-21166), we need to
conditionally use VERW based on the trustworthiness of the guest, and the
devices passed through.
Remove the PV/HVM alternatives and instead issue a VERW on the return-to-guest
path depending on the SCF_verw bit in cpuinfo spec_ctrl_flags.
Introduce spec_ctrl_init_domain() and d->arch.verw to calculate the VERW
disposition at domain creation time, and context switch the SCF_verw bit.
For now, VERW flushing is used and controlled exactly as before, but later
patches will add per-domain cases too.
No change in behaviour.
This is part of XSA-404.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Introduce a command line parameter "maxcpus" on Arm to allow adjusting
the number of CPUs to activate. Currently the limit is defined by the
config option CONFIG_NR_CPUS. Such parameter already exists on x86.
Define a parameter "maxcpus" and a corresponding static variable
max_cpus in Arm smpboot.c. Modify function smp_get_max_cpus to take
max_cpus as a limit and to return proper unsigned int instead of int.
Take the opportunity to remove redundant variable cpus from start_xen
function and to directly assign the return value from smp_get_max_cpus
to nr_cpu_ids (global variable in Xen used to store the number of CPUs
actually activated).
Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
When xs_introduce_domain is called, send out a notification on the
xenstore event channel so that any (dom0less) domain waiting for the
xenstore interface to be ready can continue with the initialization.
Before sending the notification, clear XENSTORE_RECONNECTING.
The extra notification is harmless for domains that don't require it.
In xs_wire.h update the commment on top of XENSTORE_RECONNECTING to
generalize its meaning to suit the dom0less use-case better. Also
improve docs/misc/xenstore-ring.txt.
Signed-off-by: Luca Miccio <lucmiccio@gmail.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Introduce a new "xen,enhanced" dom0less property to enable/disable PV
driver interfaces for dom0less guests. Currently only "enabled" and
"disabled" are supported property values (and empty). Leave the option
open to implement further possible values in the future (e.g.
"xenstore" to enable only xenstore.) Dom0 presence is required for now
to use "xen,enhanced" on a domU.
The configurable option is for domUs only. For dom0 we always set the
corresponding property in the Xen code to true (PV interfaces enabled.)
This patch only parses the property. Next patches will make use of it.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Acked-by: Julien Grall <jgrall@amazon.com>
CC: Julien Grall <julien@xen.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Bertrand Marquis <bertrand.marquis@arm.com>
Implement extended regions for dom0less domUs. The implementation is
based on the libxl implementation.
Also update docs for the ext_regions command line option.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Introduce domain-cpupool property of a xen,domain device tree node,
that specifies the cpupool device tree handle of a xen,cpupool node
that identifies a cpupool created at boot time where the guest will
be assigned on creation.
Add member to the xen_domctl_createdomain public interface so the
XEN_DOMCTL_INTERFACE_VERSION version is bumped.
Add public function to retrieve a pool id from the device tree
cpupool node.
Update documentation about the property.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Introduce a way to create different cpupools at boot time, this is
particularly useful on ARM big.LITTLE system where there might be the
need to have different cpupools for each type of core, but also
systems using NUMA can have different cpu pools for each node.
The feature on arm relies on a specification of the cpupools from the
device tree to build pools and assign cpus to them.
ACPI is not supported for this feature.
With this patch, cpupool0 can now have less cpus than the number of
online ones, so update the default case for opt_dom0_max_vcpus.
Documentation is created to explain the feature.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
AMD have updated their Spectre v2 guidance, and lfence/jmp is no longer
considered safe. AMD are recommending using retpoline everywhere.
Retpoline is incompatible with CET. All CET-capable hardware has efficient
IBRS (specifically, not something retrofitted in microcode), so use IBRS (and
STIBP for consistency sake).
This is a logical change on AMD, but not on Intel as the default calculations
would end up with these settings anyway. Leave behind a message if IBRS is
found to be missing.
Also update the default heuristics to never select THUNK_LFENCE. This causes
AMD CPUs to change their default to retpoline.
Also update the printed message to include the AMD MSR_SPEC_CTRL settings, and
STIBP now that we set it for consistency sake.
This is part of XSA-398 / CVE-2021-26401.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Defaults differ for Arm and x86, not the least because of v2 not even
being security supported on Arm.
Also drop a bogus sentence from gnttab_max_maptrack_frames, which was
presumably mistakenly cloned from gnttab_max_frames (albeit even there
what is being said is neither very precise nor very useful imo).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
With all the pieces now in place, turn CET-IBT on when available.
MSR_S_CET, like SMEP/SMAP, controls Ring1 meaning that ENDBR_EN can't be
enabled for Xen independently of PV32 kernels. As we already disable PV32 for
CET-SS, extend this to all CET, adjusting the documentation/comments as
appropriate.
Introduce a cet=no-ibt command line option to allow the admin to disable IBT
even when everything else is configured correctly.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Document the remaining option. Add section annotation to the variable
holding the parsed value as well as a few adjacent ones. Adjust the
types of font_height and vga_compat.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
If we get mode dimensions wrong, having the remapping size controllable
via command line option isn't going to help much. Drop the option.
While adjusting this also
- add __initdata to the variable,
- use ROUNDUP() instead of open-coding it.
Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Now that we use ioremap_wc() for mapping the frame buffer, there's no
need for this option anymore. As noted in the change introducing the
use of ioremap_wc(), mtrr_add() didn't work in certain cases anyway.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
In case Xenstore is detecting a malicious ring page modification (e.g.
an invalid producer or consumer index set by a guest) it will ignore
the connection of that guest in future.
Add a new error field to the ring page indicating that case. Add a new
feature bit in order to signal the presence of that error field.
Move the ignore_connection() function to xenstored_domain.c in order
to be able to access the ring page for setting the error indicator.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
This commit introduces a new arm-specific flag CDF_directmap to specify
that a domain should have its memory direct-map(guest physical address
== host physical address) at domain creation.
Also, add a directmap flag under struct arch_domain and use it to
reimplement is_domain_direct_mapped.
For now, direct-map is only available when statically allocated memory is
used for the domain, that is, "xen,static-mem" must be also defined in the
domain configuration.
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
The grant table operation GNTTABOP_transfer is meant to be used in
PV device backends, and it hasn't been used in Linux since the old
Xen-o-Linux days.
Add a command line sub-option to the "gnttab" option for disabling the
GNTTABOP_transfer functionality.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The February 2022 microcode is formally de-featuring TSX on the TAA-impacted
client CPUs. The backup TAA mitigation (VERW regaining its flushing side
effect) is being dropped, meaning that `smt=0 spec-ctrl=md-clear` no longer
protects against TAA on these parts.
The new functionality enumerates itself via the RTM_ALWAYS_ABORT CPUID
bit (the same as June 2021), but has its control in MSR_MCU_OPT_CTRL as
opposed to MSR_TSX_FORCE_ABORT.
TSX now defaults to being disabled on ucode load. Furthermore, if SGX is
enabled in the BIOS, TSX is locked and cannot be re-enabled. In this case,
override opt_tsx to 0, so the RTM/HLE CPUID bits get hidden by default.
While updating the command line documentation, take the opportunity to add a
paragraph explaining what TSX being disabled actually means, and how migration
compatibility works.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Currently the Xen UEFI stub can accept Xen boot arguments from
the Xen configuration file using the "options=" keyword, but also
directly from the device tree specifying xen,xen-bootargs
property.
When the configuration file is used, device tree boot arguments
are ignored and overwritten even if the keyword "options=" is
not used.
This patch handle this case, so if the Xen configuration file is not
specifying boot arguments, the device tree boot arguments will be
used, if they are present.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Specifically, this lets the user opt in to non-default features.
Collect all dom0 settings together in dom0_{en,dis}able_feat[], and apply it
to dom0's policy when other tweaks are being made.
As recalculate_cpuid_policy() is an expensive action, and dom0-cpuid= is
likely to only be used by the x86 maintainers for development purposes, forgo
the recalculation in the general case.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The example in section "UEFI boot and dom0less on ARM" has a wrong
compatible for the DTB passthrough, it is "ramdisk" instead of
"device-tree".
This patch fixes the example.
Fixes: a1743fc3a9 ("arm/efi: Use dom0less configuration when using EFI boot")
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Since the introduction of UEFI boot for Xen, the legacy
compatible strings were not supported and the stub code
was checking only the presence of “multiboot,module” to
require the Xen UEFI configuration file or not.
The documentation was not updated to specify that behavior.
Add a phrase to docs/misc/arm/device-tree/booting.txt
to clarify it.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Henry Wang