AMD have updated their Spectre v2 guidance, and lfence/jmp is no longer
considered safe. AMD are recommending using retpoline everywhere.
Update the default heuristics to never select THUNK_LFENCE.
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>
(cherry picked from commit 8d03080d2a)
The special watches "@introduceDomain" and "@releaseDomain" should be
allowed for privileged callers only, as they allow to gain information
about presence of other guests on the host. So send watch events for
those watches via privileged connections only.
In order to allow for disaggregated setups where e.g. driver domains
need to make use of those special watches add support for calling
"set permissions" for those special nodes, too.
This is part of XSA-115.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Commit 858c0be8c2 "xen/arm: Enable CPU Erratum 1165522 for Neoverse"
added a new erratum but forgot to update silicon-errata.txt.
Update the file accordingly to keep track of errata workaround in Xen.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 1814a626fb)
Inspired by Linux commit c49a0a80137c7ca7d6ced4c812c9e07a949f6f24:
There have been reports of RDRAND issues after resuming from suspend on
some AMD family 15h and family 16h systems. This issue stems from a BIOS
not performing the proper steps during resume to ensure RDRAND continues
to function properly.
Update the CPU initialization to clear the RDRAND CPUID bit for any family
15h and 16h processor that supports RDRAND. If it is known that the family
15h or family 16h system does not have an RDRAND resume issue or that the
system will not be placed in suspend, the "cpuid=rdrand" kernel parameter
can be used to stop the clearing of the RDRAND CPUID bit.
Note, that clearing the RDRAND CPUID bit does not prevent a processor
that normally supports the RDRAND instruction from executing it. So any
code that determined the support based on family and model won't #UD.
Warn if no explicit choice was given on affected hardware.
Check RDRAND functions at boot as well as after S3 resume (the retry
limit chosen is entirely arbitrary).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 93401e28a8
master date: 2020-05-27 09:49:37 +0200
RDRAND/RDSEED can be hidden using cpuid= to mitigate SRBDS if microcode
isn't available.
This is part of XSA-320 / CVE-2020-0543.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
(cherry picked from commit 7028534d84)
See patch documentation and comments.
This is part of XSA-320 / CVE-2020-0543
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 6a49b9a792)
At the moment, the diagram is only indented with 2 spaces. So pandoc
will try to badly interpret it and not display it correctly.
Fix it by indenting all the block by 4 spaces (i.e an extra 2 spaces).
Fixes: d661611d08 ("docs/markdown: Switch to using pandoc, and fix underscore escaping")
Signed-off-by: Julien Grall <julien@xen.org>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 9c8705f8fe)
(cherry picked from commit 8b60270731)
The CONTROL command (former DEBUG command) isn't specified in the
xenstore protocol doc. Add it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Backport: 4.9+
(cherry picked from commit f910c3ebc6)
DIRECTORY_PART was missing in docs/misc/xenstore.txt. Add it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
Backport: 4.9+
(cherry picked from commit 94a0252c10)
The written ABI states that %es will be set up, but libxc doesn't do so. In
practice, it breaks `rep movs` inside guests before they reload %es.
The written ABI doesn't mention %ss, but libxc does set it up. Having %ds
different to %ss is obnoxous to work with, as different registers have
different implicit segments.
Modify the spec to state that %ss is set up as a flat read/write segment.
This a) matches the Multiboot 1 spec, b) matches what is set up in practice,
and c) is the more sane behaviour for guests to use.
Fixes: 68e1183411 ('libxc: introduce a xc_dom_arch for hvm-3.0-x86_32 guests')
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wl@xen.org>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
x86/pvh: Adjust dom0's starting state
Fixes: b25fb1a04e "xen/pvh: Fix segment selector ABI"
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wl@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
master commit: b25fb1a04e
master date: 2020-02-10 15:26:09 +0000
master commit: 6ee1031362
master date: 2020-02-11 11:04:26 +0000
Due to AMD and Hygon being unable to selectively trap CR4 bit modifications
running 32-bit PV guest inside PV shim comes with significant performance
hit. Moreover, for SMEP in particular every time CR4.SMEP changes on context
switch to/from 32-bit PV guest, it gets trapped by L0 Xen which then
tries to perform global TLB invalidation for PV shim domain. This usually
results in eventual hang of a PV shim with at least several vCPUs.
Since the overall security risk is generally lower for shim Xen as it being
there more of a defense-in-depth mechanism, choose to disable SMEP/SMAP in
it by default on AMD and Hygon unless a user chose otherwise.
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: b05ec9263e
master date: 2020-01-17 16:18:20 +0100
Xen used to have single, system-wide limits for the number of grant
frames and maptrack frames a guest was allowed to create. Increasing
or decreasing this single limit on the Xen command-line would change
the limit for all guests on the system.
Later, per-domain limits for these values was created. The system-wide
limits became strict limits: domains could not be created with higher
limits, but could be created with lower limits. However, that change
also introduced a range of different "default" values into various
places in the toolstack:
- The python libxc bindings hard-coded these values to 32 and 1024,
respectively
- The libxl default values are 32 and 1024 respectively.
- xl will use the libxl default for maptrack, but does its own default
calculation for grant frames: either 32 or 64, based on the max
possible mfn.
These defaults interact poorly with the hypervisor command-line limit:
- The hypervisor command-line limit cannot be used to raise the limit
for all guests anymore, as the default in the toolstack will
effectively override this.
- If you use the hypervisor command-line limit to *reduce* the limit,
then the "default" values generated by the toolstack are too high,
and all guest creations will fail.
In other words, the toolstack defaults require any change to be
effected by having the admin explicitly specify a new value in every
guest.
In order to address this, have grant_table_init treat negative values
for max_grant_frames and max_maptrack_frames as instructions to use the
system-wide default, and have all the above toolstacks default to passing
-1 unless a different value is explicitly configured.
This restores the old behavior in that changing the hypervisor command-line
option can change the behavior for all guests, while retaining the ability
to set per-guest values. It also removes the bug that reducing the
system-wide max will cause all domains without explicit limits to fail.
NOTE: - The Ocaml bindings require the caller to always specify a value,
and the code to start a xenstored stubdomain hard-codes these to 4
and 128 respectively; this behavour will not be modified.
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
master commit: f2ae59bc4b
master date: 2019-11-29 21:43:49 +0000
The current documentation is misleading for a few reasons:
1) The synchronization happens on all exit/entry from/to the guest.
This includes from EL0 (i.e userspace).
2) Trusted guest can also generate SErrors (e.g. memory failure)
3) Without RAS support, SErrors are IMP DEFINED. Unless you have a
complete TRM in hand, you can't really make a decision.
4) The documentation is written around performance when this is not
the first concern.
The documentation is now reworked to focus on the consequences of using
serrors="panic" and avoid to go in details on the exact implementation.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Juergen Gross <jgross@suse.com>
(cherry picked from commit dfdb006636)
Per the Arm ARM (D4.5 in ARM DDI 0487E.a), SError may be precise or
imprecise.
Imprecise means the state presented to the exception handler is not
guaranteed to be consistent with any point in the excution stream from
which the exception was taken. In other words, they are likely to be
fatal as you can't return safely from them.
Without the RAS extension, the Arm architecture does not provide a way
to differentiate between imprecise and precise SError. Furthermore Xen
has no support for RAS yet. So from a software POV, there is not much
we can do.
More generally, forwarding blindly SErrors to the guest is likely to be
the wrong thing to do. Indeed, Xen is not able to know what is the
content of the SError. This may be a critical device used by the
hypervisor that is about to fail.
In a nutshell, the option serrors=forward is not safe to use in any
environment with the current state of Xen. Therefore the option and any
code related to it are completely removed.
Take the opportunity to rework the comment in do_trap_data_abort() as
all SErrors/External Abort generated by the hypervisor will result in
a crash of the system no matter what the user passed on the command
line.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Juergen Gross <jgross@suse.com>
(cherry picked from commit abb234b5ac)
When serrors=diverse is selected by the user, we will only synchronize
the pending SErrors on entry to hypervisor from guest context and exit
from guest to hypervisor context.
We don't need synchronize SErrors between guest context switch as they
would be categorized to Hypervisor generated SErrors in any case.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Juergen Gross <jgross@suse.com>
(cherry picked from commit 575186163c)
XSA-302 relies on the use of libxl's "assignable-add" feature to prepare
devices to be assigned to untrusted guests.
Unfortunately, this is not considered a strictly required step for
device assignment. The PCI passthrough documentation on the wiki
describes alternate ways of preparing devices for assignment, and
libvirt uses its own ways as well. Hosts where these alternate methods
are used will still leave the system in a vulnerable state after the
device comes back from a guest.
Default to always quarantining PCI devices, but provide a command line
option to revert back to prior behavior (such that people who both
sufficiently trust their guests and want to be able to use devices in
Dom0 again after they had been in use by a guest wouldn't need to
"manually" move such devices back from DomIO to Dom0).
This is XSA-306.
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wl@xen.org>
master commit: ba2ab00bbb
master date: 2019-11-26 14:15:01 +0100
See patch documentation and comments.
This is part of XSA-305 / CVE-2019-11135
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
To protect against the TSX Async Abort speculative vulnerability, Intel have
released new microcode for affected parts which introduce the MSR_TSX_CTRL
control, which allows TSX to be turned off. This will be architectural on
future parts.
Introduce tsx= to provide a global on/off for TSX, including its enumeration
via CPUID. Provide stub virtualisation of this MSR, as it is not exposed to
guests at the moment.
VMs may have booted before microcode is loaded, or before hosts have rebooted,
and they still want to migrate freely. A VM which booted seeing TSX can
migrate safely to hosts with TSX disabled - TSX will start unconditionally
aborting, but still behave in a manner compatible with the ABI.
The guest-visible behaviour is equivalent to late loading the microcode and
setting the RTM_DISABLE bit in the course of live patching.
This is part of XSA-305 / CVE-2019-11135
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
CVE-2018-12207 covers a set of errata on various Intel processors, whereby a
machine check exception can be generated in a corner case when an executable
mapping changes size or cacheability without TLB invalidation. HVM guest
kernels can trigger this to DoS the host.
To mitigate, in affected hardware, all EPT superpages are marked NX. When an
instruction fetch violation is observed against the superpage, the superpage
is shattered to 4k and has execute permissions restored. This prevents the
guest kernel from being able to create the necessary preconditions in the iTLB
to exploit the vulnerability.
This does come with a workload-dependent performance overhead, caused by
increased TLB pressure. Performance can be restored, if guest kernels are
trusted not to mount an attack, by specifying ept=exec-sp on the command line.
This is part of XSA-304 / CVE-2018-12207
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Both Cortex-A57 (erratum 1319537) and Cortex-A72 (erratum 1319367) can
end with corrupted TLBs if they speculate an AT instruction while S1/S2
system registers in inconsistent state.
The workaround is the same as for Cortex A-76 implemented by commit
a18be06aca "xen/arm: Implement workaround for Cortex-A76 erratum 1165522",
so it is only necessary to plumb in the cpuerrata framework.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 07e44b3d1b)
The Microarchitectural Data Sampling vulnerability is split into categories
with subtly different properties:
MLPDS - Microarchitectural Load Port Data Sampling
MSBDS - Microarchitectural Store Buffer Data Sampling
MFBDS - Microarchitectural Fill Buffer Data Sampling
MDSUM - Microarchitectural Data Sampling Uncacheable Memory
MDSUM is a special case of the other three, and isn't distinguished further.
These issues pertain to three microarchitectural buffers. The Load Ports, the
Store Buffers and the Fill Buffers. Each of these structures are flushed by
the new enhanced VERW functionality, but the conditions under which flushing
is necessary vary.
For this concise overview of the issues and default logic, the abbreviations
SP (Store Port), FB (Fill Buffer), LP (Load Port) and HT (Hyperthreading) are
used for brevity:
* Vulnerable hardware is divided into two categories - parts which suffer
from SP only, and parts with any other combination of vulnerabilities.
* SP only has an HT interaction when the thread goes idle, due to the static
partitioning of resources. LP and FB have HT interactions at all points,
due to the competitive sharing of resources. All issues potentially leak
data across the return-to-guest transition.
* The microcode which implements VERW flushing also extends MSR_FLUSH_CMD, so
we don't need to do both on the HVM return-to-guest path. However, some
parts are not vulnerable to L1TF (therefore have no MSR_FLUSH_CMD), but are
vulnerable to MDS, so do require VERW on the HVM path.
Note that we deliberately support mds=1 even without MD_CLEAR in case the
microcode has been updated but the feature bit not exposed.
This is part of XSA-297, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, CVE-2019-11091.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 3c04c258ab)
The MD_CLEAR feature can be automatically offered to guests. No
infrastructure is needed in Xen to support the guest making use of it.
This is part of XSA-297, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, CVE-2019-11091.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit d4f6116c08)
The CPUID bit and MSR are deliberately not exposed to guests, because they
won't exist on newer processors. As vPMU isn't security supported, the
misbehaviour of PCR3 isn't expected to impact production deployments.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 6be613f29b
master date: 2019-03-12 17:05:21 +0000
It's unsafe to disable IOMMU on a live system which is the case
if we're crashing since remapping hardware doesn't usually know what
to do with ongoing bus transactions and frequently raises NMI/MCE/SMI,
etc. (depends on the firmware configuration) to signal these abnormalities.
This, in turn, doesn't play well with kexec transition process as there is
no handling available at the moment for this kind of events resulting
in failures to enter the kernel.
Modern Linux kernels taught to copy all the necessary DMAR/IR tables
following kexec from the previous kernel (Xen in our case) - so it's
currently normal to keep IOMMU enabled. It might require minor changes to
kdump command line that enables IOMMU drivers (e.g. intel_iommu=on /
intremap=on) but recent kernels don't require any additional changes for
the transition to be transparent.
A fallback option is still left for compatibility with ancient crash
kernels which didn't like to have IOMMU active under their feet on boot.
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
master commit: 12c36f577d
master date: 2019-03-12 14:38:12 +0100
It turns out that this code was previously dead.
c/s dcf41790 " x86/mmcfg/drhd: Move acpi_mmcfg_init() call before calling
acpi_parse_dmar()" resulted in PCI segment 0 now having been initialised
enough for acpi_parse_one_drhd() to not take the
/* Skip checking if segment is not accessible yet. */
path unconditionally. However, some systems have DMAR tables which list
devices which are disabled by user choice (in particular, Dell PowerEdge R740
with I/O AT DMA disabled), and turning off all IOMMU functionality in this
case is entirely unhelpful behaviour.
Leave the warning which identifies the problematic devices, but drop the
remaining logic. This leaves the system in better overall state, and working
in the same way that it did in previous releases.
Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
(cherry picked from commit 74dadb8556)
The behaviour of vpmu=<bool> being exclusive of vpmu=bts|ipc|arch is odd and
contrary to Xen's normal command line parsing behaviour. Rewrite the parsing
to use the normal form, but retain the previous behaviour where the use of
bts/ipc/arch implies vpmu=true.
Parts of the documenation are stale, most notibly the HVM-only statement.
Update it for consistency and correctness.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Document provides a brief introduction to the Argo interdomain
communication mechanism and a detailed description of the granular
locking used within the Argo implementation.
Signed-off-by: Christopher Clark <christopher.clark6@baesystems.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
The register op is used by a domain to register a region of memory for
receiving messages from either a specified other domain, or, if specifying a
wildcard, any domain.
This operation creates a mapping within Xen's private address space that
will remain resident for the lifetime of the ring. In subsequent commits,
the hypervisor will use this mapping to copy data from a sending domain into
this registered ring, making it accessible to the domain that registered the
ring to receive data.
Wildcard any-sender rings are default disabled and registration will be
refused with EPERM unless they have been specifically enabled with the
new mac-permissive flag that is added to the argo boot option here. The
reason why the default for wildcard rings is 'deny' is that there is
currently no means to protect the ring from DoS by a noisy domain
spamming the ring, affecting other domains ability to send to it. This
will be addressed with XSM policy controls in subsequent work.
Since denying access to any-sender rings is a significant functional
constraint, the new option "mac-permissive" for the argo bootparam
enables overriding this. eg: "argo=1,mac-permissive=1"
The p2m type of the memory supplied by the guest for the ring must be
p2m_ram_rw and the memory will be pinned as PGT_writable_page while the ring
is registered.
This hypercall op and its interface currently only supports 4K-sized pages.
Signed-off-by: Christopher Clark <christopher.clark6@baesystems.com>
Tested-by: Chris Patterson <pattersonc@ainfosec.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Initialises basic data structures and performs teardown of argo state
for domain shutdown.
Inclusion of the Argo implementation is dependent on CONFIG_ARGO.
Introduces a new Xen command line parameter 'argo': bool to enable/disable
the argo hypercall. Defaults to disabled.
New headers:
public/argo.h: with definions of addresses and ring structure, including
indexes for atomic update for communication between domain and hypervisor.
xen/argo.h: to expose the hooks for integration into domain lifecycle:
argo_init: per-domain init of argo data structures for domain_create.
argo_destroy: teardown for domain_destroy and the error exit
path of domain_create.
argo_soft_reset: reset of domain state for domain_soft_reset.
Adds a new field to struct domain: struct argo_domain *argo;
In accordance with recent work on _domain_destroy, argo_destroy is
idempotent. It will tear down: all rings registered by this domain, all
rings where this domain is the single sender (ie. specified partner,
non-wildcard rings), and all pending notifications where this domain is
awaiting signal about available space in the rings of other domains.
A count will be maintained of the number of rings that a domain has
registered in order to limit it below the fixed maximum limit defined here.
Macros are defined to verify the internal locking state within the argo
implementation. The macros are ASSERTed on entry to functions to validate
and document the required lock state prior to calling.
The hash function for the hashtables that hold ring state is derived from
the string hashing function djb2 (http://www.cse.yorku.ca/~oz/hash.html)
by Daniel J. Bernstein. Basic testing with a limited number of domains and
ports has shown reasonable distribution for the table size.
The software license on the public header is the BSD license, standard
procedure for the public Xen headers. The public header was originally
posted under a GPL license at: [1]:
https://lists.xenproject.org/archives/html/xen-devel/2013-05/msg02710.html
The following ACK by Lars Kurth is to confirm that only people being
employees of Citrix contributed to the header files in the series posted at
[1] and that thus the copyright of the files in question is fully owned by
Citrix. The ACK also confirms that Citrix is happy for the header files to
be published under a BSD license in this series (which is based on [1]).
Signed-off-by: Christopher Clark <christopher.clark6@baesystems.com>
Acked-by: Lars Kurth <lars.kurth@citrix.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Tested-by: Chris Patterson <pattersonc@ainfosec.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
xen-bugtool relies on code that has been removed in commit 9e8672f1c3
"tools: remove xend and associated python modules", more than 5 years
ago. Remove it, since it confuses users.
-$ /usr/sbin/xen-bugtool
Traceback (most recent call last):
File "/usr/sbin/xen-bugtool", line 9, in <module>
from xen.util import bugtool
ImportError: No module named xen.util
Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=866380
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Early version of Cortex-A76 can end-up with corrupt TLBs if they
speculate an AT instruction while the S1/S2 system registers are in an
inconsistent state.
This can happen during guest context switch and when invalidating the
TLBs for other than the current VMID.
The workaround implemented in Xen will:
- Use an empty stage-2 with a reserved VMID while context switching
between 2 guests
- Use an empty stage-2 with the VMID where TLBs need to be flushed
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Andrii Anisov <andrii_anisov@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Remove "chatty" and redundant information from the xl man page;
restrict it to functional descriptions only, and point instead to
qemu-depriv.pandoc and SUPPORT.md as locations for "canonical"
information.
Add a man page entry for device_model_user.
Update qemu-deprivilege.pandoc:
Changes in missing feature list:
- Migration is functional
- But qdisk backends are not
Add a missing restriction list.
The following statements from the man page are dropped:
- Mentioning PV; PV guests never have a device model.
- Drop the confusing statement about stdvga and cirrus vga options.
- Re-used domain IDs are now handled.
- Device models should no longer be able to create world-readable
files on dom0's filesystem.
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
For development purposes, it is very convenient to boot Xen as a PVH guest,
with an XTF PV or PVH "dom0". The edit-compile-go cycle is a matter of
seconds, and you can reasonably insert printk() debugging in places which
which would be completely infeasible when booting fully-fledged guests.
However, the PVH dom0 path insists on having a working IOMMU, which doesn't
exist when virtualised as a PVH guest, and isn't necessary for XTF anyway.
Introduce a developer mode to skip the IOMMU requirement.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
This option is unique to x86 PV dom0's, but it is not sensible to have a
catch-all which blindly maps all non-RAM regions into the IOMMU.
The map-reserved option remains, and covers all the buggy firmware issues that
I am aware of. The two common cases are legacy USB keyboard emulation, and
the BMC mailbox used by vendor firmware in NICs/HBAs to report information
back to the iLO/iDRAC/etc for remote remote management purposes.
A specific advantage of this change is that x86 dom0's IOMMU setup is now
consistent between PV and PVH.
This change is not expected to have any impact, due to map-reserved remaining.
In the unlikely case that it does cause an issue, we should introduce other
map-$SPECIFIC options rather than re-introducing this catch-all.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Update parse_efi_param() to use parse_boolean() for "rs", so it behaves
like other Xen booleans.
However, change "attr=uc" to not be a boolean. "no-attr=uc" is ambiguous and
shouldn't be accepted, but accept "attr=no" as an acceptable alternative.
Update the command line documentation for consistency.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Second try, this time also works for all links to xen-vbd-interface(7).
We don't try anymore to have pod2html generate relative links, instead
we do it ourself.
First, we modify all links to man pages to have what looks like an
absolute URL and pod2html will just write it in the html output.
Absolute URL in POD are in the form L<text|scheme:...> so let's just use
a scheme that isn't real, but easy to find in the resulting html output:
"relative:".
Then we fix the output and remove all the bogus scheme "relative" and
can end up with nice relative links.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Having a pvh boolean isn't ideal. If we gain a 3rd virtulsation mode,
what does `dom0=no-pvh` mean?
Change the syntax to be "dom0 = pv | pvh" which offers an option to more
obviously select PV mode. Hide both options behind the relevent
CONFIG_* settings, and default to PVH mode when CONFIG_PV is compiled
out.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Alter parse_pci_param() to use parse_boolean(), so the sub options
behave like other Xen booleans.
Update the command line documentation for consistency.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Update parse_iommu_param() to uniformly use parse_boolean(), so the sub
booleans behave like other Xen boolean options. Reposition the
custom_param() to avoid a forward declaration of parse_iommu_param().
Rewrite the command line documentation almost from scratch, including
far more detail.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Update to the latest metadata style, and discuss the options more
completely where appropriate.
Drop the redundant comment beside parse_dom0_param() - it is already out
of sync with the main documentation. Also drop the individual
documentation for deprecated options which refer to their newer
versions, for the same reason.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Currently, all links to other man pages are sent to
http://man.he.net/man$mansection/$manpage, but that site doesn't have
Xen man pages, so all links to other Xen man pages are broken.
In order to fix that, this is going to be a bit complex.
First, we need to teach pod2html on where other .pod files can be found,
otherwise it isn't going make any links to our pages. This is done with
--podpath.
Second, pod2html doesn't actually understand our format
"$manpage.$mansection.pod". But instead of teaching it (which is
probably impossible) we are going to modify our .pod files in order to
tell pod2html which file to look for. This is done with the sed command
by transforming for example: "L<xl.conf(5)>" to "L<xl.conf(5)|xl.conf.5>".
Last but not least, in order to have relative links to the other
generated man page, we are going against the rules, we are going to use
"--htmlroot=." so that pod2html doesn't prepand "/" to all "relative"
links. We are also going to `cd` into the "man" dir and set podpath to
"." so that pod2html is going to generate relative links to other pod
file in the form "./$man" insteadof "man/$man" or "../$man" with other
compination of options. The result of --podpath + --podroot can be check
in pod2html's cache file "pod2html.tmp".
All of this is going to generate links in the form "./$html_manpage".
But all of this doesn't work for xen-vbd-interface(7), because it's not
a pod file... maybe we could generate pod2html's cache (pod2html.tmp)
file to add en entry.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
As a short term alternative to deleting the code, default its building
to off (overridable in EXPERT mode only). Additionally make sure other
related baggage (LZO code) won't be carried when the option is off (with
TMEM scheduled to be deleted anyway, I didn't want to introduce a
separate Kconfig option to control the LZO compression code, and hence
CONFIG_TMEM is used directly there). Similarly I couldn't be bothered to
add actual content to the command line option doc for the two affected
options.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Andrew Cooper
Juergen Gross
Julien Grall
Jan Beulich
Julien Grall
Igor Druzhinin
George Dunlap
Julien Grall
Christopher Clark
Hans van Kranenburg
Anthony PERARD
Ian Jackson