91 Commits
Author SHA1 Message Date
Jan Beulich c7e442938e xl/parse: mark as GNU source
Very old glibc (2.4 in the observed case) declares strndup() only when
_GNU_SOURCE is defined.

Fixes: ad860c6454 ("tools/xl: add xl commands for xenstore quota operations")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
2026-05-18 08:59:40 +02:00
Juergen Gross ea3099e191 tools/xl: add support for xenstore quota setting via domain config
Add a new "xenstore_quota" domain config parameter for setting the
Xenstore quota of a new domain via a list of <quota>=<val> items.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2026-03-27 12:06:37 +01:00
Juergen Gross ad860c6454 tools/xl: add xl commands for xenstore quota operations
Add "xl xenstore-quota-get" and "xl xenstore-quota-set" commands for
retrieving and setting global and per-domain Xenstore quota.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2026-03-27 12:06:37 +01:00
Anthony PERARD 4b71a86eaa tools/xl: Fix when config "cpus" is set, but "vcpus" is missing
If we start a guest with 'cpus="all"' and without 'vcpus' or
'maxvcpus' (or sets them to 0), we execute parse_vcpu_affinity() with
`num_cpus=0`. This malloc "b_info->vcpu_hard_affinity" with a buffer
of size 0, which is implementation defined, and we still initialise
the "first" bitmap of this allocation, which mean we have a buffer
overflow.

On Alpine Linux, this result in a segv when the buffer is being
disposed of.

Since libxl will assume there's at least 1 vcpu, we default to 1 in
xl as well. (libxl sets max_vcpus to 1 if unset, and allocate
avail_vcpus if its size is 0.)

Link: https://gitlab.alpinelinux.org/alpine/aports/-/issues/17809
Fixes: a5dbdcf674 ("libxl/xl: push VCPU affinity pinning down to libxl")
Signed-off-by: Anthony PERARD <anthony.perard@vates.tech>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
2026-03-02 15:39:58 +01:00
Grygorii Strashko 10e7473d60 xen/arm: scmi-smc: passthrough SCMI SMC to domain, single agent
The commit 3e322bef8b ("xen/arm: firmware: Add SCMI over SMC calls
handling layer") introduces simple driver which forwards SCMI over SMC
calls from hwdom/dom0 to EL3 firmware (TF-A) with a single SCMI OSPM agent
support. While it is working gracefully for hwdom/dom0 use case it doesn't
cover "thin Dom0 with guest domain, which serves as Driver domain"
use-case. In this case HW need to be enable in Driver domain and dom0 is
performing only control functions.

The EL3 SCMI firmware (TF-A) with a single SCMI OSPM agent support is
pretty generic case for the default vendors SDK and new platforms.

This patch enables passthrough of SCMI SMC single agent interface to the
one guest domain serving as Driver domain.

Configure Dom0 to enable SCMI passthrough:

 - dom0: add scmi-smc-passthrough to the Xen Command Line

Enabled SCMI passthrough for guest using toolstack in the following way:

 - domD: xl.cfg add "arm_sci" option as below

   arm_sci = "type=scmi_smc"

 - domD: xl.cfg enable access to the "arm,scmi-shmem"

iomem = [
    "47ff0,1@22001",
]

 - domD: add SCMI nodes to the Driver domain partial device tree as in the
 below example:

passthrough {
   scmi_shm_0: sram@22001000 {
       compatible = "arm,scmi-shmem";
       reg = <0x0 0x22001000 0x0 0x1000>;
   };

   firmware {
        compatible = "simple-bus";
            scmi: scmi {
                compatible = "arm,scmi-smc";
                shmem = <&scmi_shm_0>;
                ...
            }
    }
}

dom0less case configuration:

- add "xen,sci_type" property for required DomU ("xen,domain") node

   xen,sci_type="scmi_smc"

- add scmi nodes to the Driver domain partial device tree the same way
as above and enable access to the "arm,scmi-shmem" according to
dom0less documentation. For example:

  scmi_shm_0: sram@22001000 {
        compatible = "arm,scmi-shmem";
        reg = <0x00 0x22001000 0x00 0x1000>;
->        xen,reg = <0x0 0x47ff0000 0x0 0x1000 0x0 0x22001000>;
->        xen,force-assign-without-iommu;
  };

The SCMI SMC single agent interface can be enabled for one and only one
domain. In general, the configuration is similar to any other HW
passthrough, except explicitly enabling SCMI with "arm_sci" xl.cfg option.

Note that "arm,scmi-smc" and "arm,scmi-shmem" nodes will be removed from
dom0/hwdom DT when "scmi-smc-passthrough" cmdline parameter was provided.

Signed-off-by: Grygorii Strashko <grygorii_strashko@epam.com>
Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech> # tools
2025-09-04 12:11:44 -07:00
Juergen Gross f6c990ac3c tools: allow to limit xenstore features via guest config
Add a guest config parameter "xenstore_feature_mask" allowing to limit
the Xenstore features the guest can see and use. This can be needed in
order to allow migrating a guest to a host running a Xenstore version
providing less features than the source host.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Acked-by: Nick Rosbrook <enr0n@ubuntu.com> # tools/golang
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2025-08-01 16:00:13 +02:00
Petr Beneš 3712f464fd tools/xl: Add altp2m_count parameter
Introduce a new altp2m_count parameter to control the maximum number of altp2m
views a domain can use. By default, if altp2m_count is unspecified and altp2m
is enabled, the value is set to 10, reflecting the legacy behavior.

This change is preparatory; it establishes the groundwork for the feature but
does not activate it.

Signed-off-by: Petr Beneš <w1benny@gmail.com>
Acked-by: Nick Rosbrook <enr0n@ubuntu.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2025-07-22 08:51:24 +02:00
Jan Beulich 05c574feeb Revert "tools/xl: Add altp2m_count parameter"
This reverts commit 3ce6f7bacc, for
breaking CI.
2025-07-07 16:24:04 +02:00
Petr Beneš 3ce6f7bacc tools/xl: Add altp2m_count parameter
Introduce a new altp2m_count parameter to control the maximum number of altp2m
views a domain can use. By default, if altp2m_count is unspecified and altp2m
is enabled, the value is set to 10, reflecting the legacy behavior.

This change is preparatory; it establishes the groundwork for the feature but
does not activate it.

Signed-off-by: Petr Beneš <w1benny@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Nick Rosbrook <enr0n@ubuntu.com>
2025-07-07 11:47:59 +02:00
Roger Pau Monne 22650d6054 x86/hvmloader: select xen platform pci MMIO BAR UC or WB MTRR cache attribute
The Xen platform PCI device (vendor ID 0x5853) exposed to x86 HVM guests
doesn't have the functionality of a traditional PCI device.  The exposed
MMIO BAR is used by some guests (including Linux) as a safe place to map
foreign memory, including the grant table itself.

Traditionally BARs from devices have the uncacheable (UC) cache attribute
from the MTRR, to ensure correct functionality of such devices.  hvmloader
mimics this behavior and sets the MTRR attributes of both the low and high
PCI MMIO windows (where BARs of PCI devices reside) as UC in MTRR.

This however causes performance issues for users of the Xen platform PCI
device BAR, as for the purposes of mapping remote memory there's no need to
use the UC attribute.  On Intel systems this is worked around by using
iPAT, that allows the hypervisor to force the effective cache attribute of
a p2m entry regardless of the guest PAT value.  AMD however doesn't have an
equivalent of iPAT, and guest PAT values are always considered.

Linux commit:

41925b105e34 xen: replace xen_remap() with memremap()

Attempted to mitigate this by forcing mappings of the grant-table to use
the write-back (WB) cache attribute.  However Linux memremap() takes MTRRs
into account to calculate which PAT type to use, and seeing the MTRR cache
attribute for the region being UC the PAT also ends up as UC, regardless of
the caller having requested WB.

As a workaround to allow current Linux to map the grant-table as WB using
memremap() introduce an xl.cfg option (xen_platform_pci_bar_uc=0) that can
be used to select whether the Xen platform PCI device BAR will have the UC
attribute in MTRR.  Such workaround in hvmloader should also be paired with
a fix for Linux so it attempts to change the MTRR of the Xen platform PCI
device BAR to WB by itself.

Overall, the long term solution would be to provide the guest with a safe
range in the guest physical address space where mappings to foreign pages
can be created.

Some vif throughput performance figures provided by Anthoine from a 8
vCPUs, 4GB of RAM HVM guest(s) running on AMD hardware:

Without this patch:
vm -> dom0: 1.1Gb/s
vm -> vm:   5.0Gb/s

With the patch:
vm -> dom0: 4.5Gb/s
vm -> vm:   7.0Gb/s

Reported-by: Anthoine Bourgeois <anthoine.bourgeois@vates.tech>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com> # hvmloader
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2025-06-18 09:30:11 +02:00
Edgar E. Iglesias d057628757 tools/arm: Add the trap_unmapped_accesses xl config option
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2025-06-17 10:59:04 -07:00
Juergen Gross 19ab8356ab tools: remove support for running a guest with qemu-traditional
Remove the code in tools for running a guest with qemu-traditional.
This covers xl, libxl, libacpi, hvmloader and the related python and
go bindings.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com> # hvmloader
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2025-06-02 10:31:21 +02:00
Juergen Gross e1ccced4af tools/xl: fix channel configuration setting
Channels work differently than other device types: their devid should
be -1 initially in order to distinguish them from the primary console
which has the devid of 0.

So when parsing the channel configuration, use
ARRAY_EXTEND_INIT_NODEVID() in order to avoid overwriting the devid
set by libxl_device_channel_init().

Fixes: 3a66796347 ("libxl: set channel devid when not provided by application")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2025-03-05 16:37:37 +01:00
Carlo Nonato 748bd725fb tools: add support for cache coloring configuration
Add a new "llc_colors" parameter that defines the LLC color assignment for
a domain. The user can specify one or more color ranges using the same
syntax used everywhere else for color config described in the
documentation.
The parameter is defined as a list of strings that represent the color
ranges.

Documentation is also added.
Golang bindings are regenerated.

Based on original work from: Luca Miccio <lucmiccio@gmail.com>

Signed-off-by: Carlo Nonato <carlo.nonato@minervasys.tech>
Signed-off-by: Marco Solieri <marco.solieri@minervasys.tech>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2024-12-19 19:24:31 +01:00
Henry Wang 6f588194d9 tools/arm: Introduce the "nr_spis" xl config entry
Currently, the number of SPIs allocated to the domain is only
configurable for Dom0less DomUs. Xen domains are supposed to be
platform agnostics and therefore the numbers of SPIs for libxl
guests should not be based on the hardware.

Introduce a new xl config entry for Arm to provide a method for
user to decide the number of SPIs. This would help to avoid
bumping the `config->arch.nr_spis` in libxl everytime there is a
new platform with increased SPI numbers.

Update the doc and the golang bindings accordingly.

Signed-off-by: Henry Wang <xin.wang2@amd.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
2024-05-24 16:26:22 -07:00
Leigh Brown 0cc01c603f tools/xl: add vlan keyword to vif option
Update parse_nic_config() to support a new `vlan' keyword. This
keyword specifies the VLAN configuration to assign to the VIF when
attaching it to the bridge port, on operating systems that support
the capability (e.g. Linux). The vlan keyword will allow one or
more VLANs to be configured on the VIF when adding it to the bridge
port. This will be done by the vif-bridge script and functions.

Signed-off-by: Leigh Brown <leigh@solinno.co.uk>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
2024-05-15 19:59:52 +01:00
Elliott Mitchell 6eb13b6b1d tools/xl_parse: remove message for tsc mode string
Normal behavior is to be silent.  Generating a message for the preferred
input can be mistaken for an error.  As such remove this message to match
other conditions.

Signed-off-by: Elliott Mitchell <ehem+xen@m5p.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2024-03-21 09:46:13 +01:00
Juergen Gross 4287a71f9b tools/xl: support new 9pfs backend xen_9pfsd
Add support for the new 9pfs backend "xen_9pfsd". For this backend type
the tag defaults to "Xen" and the host side path to
"/var/log/xen/guests/<dom-name>".

Do most of the default settings in libxl. Unfortunately the default
path can't easily be set in libxl, as the domain name isn't available
in the related 9pfs specific function.

Settings the defaults in libxl requires to move the sanity checking
of 9pfs parameters from xl to libxl, too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2024-02-23 17:43:06 +00:00
Roger Pau Monne 024e7131be tools: don't expose XENFEAT_hvm_pirqs by default
The HVM pirq feature allows routing interrupts from both physical and emulated
devices over event channels, this was done a performance improvement.  However
its usage is fully undocumented, and the only reference implementation is in
Linux.  It defeats the purpose of local APIC hardware virtualization, because
when using it interrupts avoid the usage of the local APIC altogether.

It has also been reported to not work properly with certain devices, at least
when using some AMD GPUs Linux attempts to route interrupts over event
channels, but Xen doesn't correctly detect such routing, which leads to the
hypervisor complaining with:

(XEN) d15v0: Unsupported MSI delivery mode 7 for Dom15

When MSIs are attempted to be routed over event channels the entry delivery
mode is set to ExtINT, but Xen doesn't detect such routing and attempts to
inject the interrupt following the native MSI path, and the ExtINT delivery
mode is not supported.

Disable HVM PIRQs by default and provide a per-domain option in xl.cfg to
enable such feature.  Also for backwards compatibility keep the feature enabled
for any resumed domains that don't have an explicit selection.

Note that the only user of the feature (Linux) is also able to handle native
interrupts fine, as the feature was already not used if Xen reported local APIC
hardware virtualization active.

Link: https://github.com/QubesOS/qubes-issues/issues/7971
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-01-25 17:46:57 +00:00
Roger Pau Monne 1f762642d2 libxl: add support for running bootloader in restricted mode
Much like the device model depriv mode, add the same kind of support for the
bootloader.  Such feature allows passing a UID as a parameter for the
bootloader to run as, together with the bootloader itself taking the necessary
actions to isolate.

Note that the user to run the bootloader as must have the right permissions to
access the guest disk image (in read mode only), and that the bootloader will
be run in non-interactive mode when restricted.

If enabled bootloader restrict mode will attempt to re-use the user(s) from the
QEMU depriv implementation if no user is provided on the configuration file or
the environment.  See docs/features/qemu-deprivilege.pandoc for more
information about how to setup those users.

Bootloader restrict mode is not enabled by default as it requires certain
setup to be done first (setup of the user(s) to use in restrict mode).

This is part of XSA-443 / CVE-2023-34325

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2023-10-11 06:36:50 +01:00
Juergen Gross a8a7c33e7d tools/xl: reject bootloader=pygrub in case pygrub is disabled
In case Xen has been configured with "--disable-pygrub", don't accept
the domain config option "bootloader=pygrub".

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2023-08-09 09:05:55 +02:00
Roger Pau Monne d638fe233c libxl: use the cpuid feature names from cpufeatureset.h
The current implementation in libxl_cpuid_parse_config() requires
keeping a list of cpuid feature bits that should be mostly in sync
with the contents of cpufeatureset.h.

Avoid such duplication by using the automatically generated list of
cpuid features in INIT_FEATURE_NAMES in order to map feature names to
featureset bits, and then translate from featureset bits into cpuid
leaf, subleaf, register tuple.

Note that the full contents of the previous cpuid translation table
can't be removed.  That's because some feature names allowed by libxl
are not described in the featuresets, or because naming has diverged
and the previous nomenclature is preserved for compatibility reasons.

Should result in no functional change observed by callers, albeit some
new cpuid features will be available as a result of the change.

While there constify cpuid_flags name field.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2023-07-26 10:56:27 +01:00
Viresh Kumar c14254065f libxl: arm: Add grant_usage parameter for virtio devices
Currently, the grant mapping related device tree properties are added if
the backend domain is not Dom0. While Dom0 is privileged and can do
foreign mapping for the entire guest memory, it is still desired for
Dom0 to access guest's memory via grant mappings and hence map only what
is required.

This commit adds the "grant_usage" parameter for virtio devices, which
provides better control over the functionality.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: George Dunlap <george.dunlap@cloud.com>
2023-07-24 14:11:35 +02:00
Luca Fancellu b46e8207d0 xen/tools: add sve parameter in XL configuration
Add sve parameter in XL configuration to allow guests to use
SVE feature.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2023-06-07 11:21:41 +01:00
Juergen Gross 95b757598f tools/xl: rework p9 config parsing
Rework the config parsing of a p9 device to use the
split_string_into_pair() function instead of open coding it.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2023-03-23 09:18:26 +01:00
Juergen Gross 4bad14a133 tools/xl: make split_string_into_pair() more usable
Today split_string_into_pair() will not really do what its name is
suggesting: instead of splitting a string into a pair of strings using
a delimiter, it will return the first two strings of the initial string
by using the delimiter.

This is never what the callers want, so modify split_string_into_pair()
to split the string only at the first delimiter found, resulting in
something like "x=a=b" to be split into "x" and "a=b" when being called
with "=" as the delimiter. Today the returned strings would be "x" and
"a".

At the same time switch the delimiter from "const char *" (allowing
multiple delimiter characters) to "char" (a single character only), as
this makes the function more simple without breaking any use cases.

Suggested-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2023-03-23 09:18:12 +01:00
Juergen Gross eee0d79134 tools/xl: allow split_string_into_pair() to trim values
Most use cases of split_string_into_pair() are requiring the returned
strings to be white space trimmed.

In order to avoid the same code pattern multiple times, add a predicate
parameter to split_string_into_pair() which can be specified to call
trim() with that predicate for the string pair returned. Specifying
NULL for the predicate will avoid the call of trim().

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2023-03-22 10:00:09 +01:00
Jason Andryuk 38bdfa44cc xl/libxl: Add OEM string support to smbios
Add support for OEM strings in the SMBIOS type 11.

hvmloader checks them sequentially, so hide the implementation detail.
Allow multiple plain oem= items and assign the numeric values
internally.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2023-03-15 18:41:46 +00:00
Jason Andryuk 9aeb3a20c4 xl/libxl: Add ability to specify SMBIOS strings
hvm_xs_strings.h specifies xenstore entries which can be used to set or
override smbios strings.  hvmloader has support for reading them, but
xl/libxl support is not wired up.

Allow specifying the strings with the new xl.cfg option:
smbios=["bios_vendor=Xen Project","system_version=1.0"]

In terms of strings, the SMBIOS specification 3.5 says:
https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.5.0.pdf
"""
Strings must be encoded as UTF-8 with no byte order mark (BOM). For
compatibility with older SMBIOS parsers, US-ASCII characters should be
used.  NOTE There is no limit on the length of each individual text
string. However, the length of the entire structure table (including all
strings) must be reported in the Structure Table Length field of the
32-bit Structure Table Entry Point (see 5.2.1) and/or the Structure
Table Maximum Size field of the 64-bit Structure Table Entry Point (see
5.2.2).
"""

The strings aren't checked for utf-8 or length.  hvmloader has a sanity
check on the overall length.

The libxl_smbios_type enum starts at 1 since otherwise the 0th key is
not printed in the json output.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2023-03-15 18:41:46 +00:00
Viresh Kumar 953efa0b7b xl: add support to parse generic virtio device
This patch adds basic support for parsing generic Virtio backend.

An example of domain configuration for mmio based Virtio I2C device is:
virtio = ["type=virtio,device22,transport=mmio"]

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2022-12-14 12:03:25 +01:00
Andrew Cooper e5ac68a011 x86/hvm: Revert per-domain APIC acceleration support
I was really hoping to avoid this, but its now too late in the 4.17 freeze and
we still don't have working fixes.

The in-Xen calculations for assistance capabilities are buggy.  For the
avoidance of doubt, the original intention was to be able to control every
aspect of a APIC acceleration so we could comprehensively test Xen's support,
as it has proved to be buggy time and time again.

Even after a protracted discussion on what the new API ought to mean, attempts
to apply it to the existing logic have been unsuccessful, proving that the
API/ABI is too complicated for most people to reason about.

This reverts most of:
  2ce11ce249
  6b2b9b3405

leaving in place the non-APIC specific changes (minimal as they are).

This takes us back to the behaviour of Xen 4.16 where APIC acceleration is
configured on a per system basis.

This work will be revisted in due course.

Fixes: 2ce11ce249 ("x86/HVM: allow per-domain usage of hardware virtualized APIC")
Fixes: 6b2b9b3405 ("x86: report Interrupt Controller Virtualization capabilities")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
2022-11-17 16:51:51 +00:00
Jane Malalane 2ce11ce249 x86/HVM: allow per-domain usage of hardware virtualized APIC
Introduce a new per-domain creation x86 specific flag to
select whether hardware assisted virtualization should be used for
x{2}APIC.

A per-domain option is added to xl in order to select the usage of
x{2}APIC hardware assisted virtualization, as well as a global
configuration option.

Having all APIC interaction exit to Xen for emulation is slow and can
induce much overhead. Hardware can speed up x{2}APIC by decoding the
APIC access and providing a VM exit with a more specific exit reason
than a regular EPT fault or by altogether avoiding a VM exit.

On the other hand, being able to disable x{2}APIC hardware assisted
virtualization can be useful for testing and debugging purposes.

Note:

- vmx_install_vlapic_mapping doesn't require modifications regardless
of whether the guest has "Virtualize APIC accesses" enabled or not,
i.e., setting the APIC_ACCESS_ADDR VMCS field is fine so long as
virtualize_apic_accesses is supported by the CPU.

- Both per-domain and global assisted_x{2}apic options are not part of
the migration stream, unless explicitly set in the respective
configuration files. Default settings of assisted_x{2}apic done
internally by the toolstack, based on host capabilities at create
time, are not migrated.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jane Malalane <jane.malalane@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Reviewed-by: "Roger Pau Monné" <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
2022-07-11 12:15:05 +02:00
Roger Pau Monne 54d8f27d04 tools/libxl: report trusted backend status to frontends
Allow administrators to notify a frontend driver that it's backend
counterpart is not to be trusted, so the frontend can deploy whatever
mitigations required in order to secure itself.

Allow such option for disk and network frontends only, as those are
the only hardened ones currently supported.

This is part of XSA-403

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2022-07-05 14:16:26 +02:00
Jason Andryuk e45ad0b1b0 xl: Fix global pci options
commit babde47a3f "introduce a 'passthrough' configuration option to
xl.cfg..." moved the pci list parsing ahead of the global pci option
parsing.  This broke the global pci configuration options since they
need to be set first so that looping over the pci devices assigns their
values.

Move the global pci options ahead of the pci list to restore their
function.

Fixes: babde47a3f ("introduce a 'passthrough' configuration option to xl.cfg...")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2022-03-31 19:48:12 +01:00
Roger Pau Monne 7379f9e10a gnttab: allow setting max version per-domain
Introduce a new domain create field so that toolstack can specify the
maximum grant table version usable by the domain. This is plumbed into
xl and settable by the user as max_grant_version.

Previously this was only settable on a per host basis using the
gnttab command line option.

Note the version is specified using 4 bits, which leaves room to
specify up to grant table version 15. Given that we only have 2 grant
table versions right now, and a new version is unlikely in the near
future using 4 bits seems more than enough.

xenstored stubdomains are limited to grant table v1 because the
current MiniOS code used to build them only has support for grants v1.
There are existing limits set for xenstored stubdomains at creation
time that already match the defaults in MiniOS.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
2021-11-08 15:10:05 +00:00
Michal Orzel dbb948110a xen: Expose the PMU to the guests
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>
2021-10-13 15:10:38 +01:00
Scott Davis ce233b1031 tools/xl: Add stubdomain_cmdline option to xl.cfg
This adds an option to the xl domain configuration file syntax for specifying
a kernel command line for device-model stubdomains. It is intended for use with
Linux-based stubdomains.

Signed-off-by: Scott Davis <scott.davis@starlab.io>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
2021-07-27 14:22:01 +01:00
Roger Pau Monné 0570d7f276 x86/msr: introduce an option for compatible MSR behavior selection
Introduce an option to allow selecting a behavior similar to the pre
Xen 4.15 one for accesses to MSRs not explicitly handled. Since commit
84e848fd7a and 322ec7c89f accesses to MSRs not explicitly
handled by Xen result in the injection of a #GP to the guest. This
is a behavior change since previously a #GP was only injected if
accessing the MSR on the real hardware would also trigger a #GP, or if
the attempted to be set bits wouldn't match the hardware values (for
PV). The reasons for not leaking hardware MSR values and injecting a
#GP are fully valid, so the solution proposed here should be
considered a temporary workaround until all the required MSRs are
properly handled.

This seems to be problematic for some guests, so introduce an option
to fallback to this kind of legacy behavior without leaking the
underlying MSR values to the guest.

When the option is set, for both PV and HVM don't inject a #GP to the
guest on MSR read if reading the underlying MSR doesn't result in a
#GP, do the same for writes and simply discard the value to be written
on that case.

Note that for guests restored or migrated from previous Xen versions
the option is enabled by default, in order to keep a compatible
MSR behavior. Such compatibility is done at the libxl layer, to avoid
higher-level toolstacks from having to know the details about this flag.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
2021-03-12 08:59:56 +01:00
Michał Leszczyński 45ba9a7d76 tools/[lib]xl: Add vmtrace_buf_size parameter
Allow to specify the size of per-vCPU trace buffer upon
domain creation. This is zero by default (meaning: not enabled).

Signed-off-by: Michał Leszczyński <michal.leszczynski@cert.pl>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
2021-02-05 17:37:27 +00:00
Paul Durrant bdc0799fe2 libxlu: introduce xlu_pci_parse_spec_string()
This patch largely re-writes the code to parse a PCI_SPEC_STRING and enters
it via the newly introduced function. The new parser also deals with 'bdf'
and 'vslot' as non-positional paramaters, as per the documentation in
xl-pci-configuration(5).

The existing xlu_pci_parse_bdf() function remains, but now strictly parses
BDF values. Some existing callers of xlu_pci_parse_bdf() are
modified to call xlu_pci_parse_spec_string() as per the documentation in xl(1).

NOTE: Usage text in xl_cmdtable.c and error messages are also modified
      appropriately.
      As a side-effect this patch also fixes a bug where using '*' to specify
      all functions would lead to an assertion failure at the end of
      xlu_pci_parse_bdf().

Fixes: d25cc3ec93 ("libxl: workaround gcc 10.2 maybe-uninitialized warning")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2021-01-21 15:20:40 +00:00
Wei Liu ac6a0af387 Revert patches that break libxl API
This patch reverts eight patches from staging.

The offending patch is the one that introduced libxl_pci_bdf (last one
in the list). The rest depend on that patch so they are also reverted.

8bf0fab142 "libxl / libxlu: support 'xl pci-attach/detach' by name"
e1141654c3 "docs/man: modify xl-pci-configuration(5) to add 'name' field to PCI_SPEC_STRING"
93c16ae47b "xl: support naming of assignable devices"
5ab684cb3e "libxl: introduce libxl_pci_bdf_assignable_add/remove/list/list_free(), ..."
66c2fbc6e8 "libxl: convert internal functions in libxl_pci.c..."
f73c5dd56d "docs/man: modify xl(1) in preparation for naming of assignable devices"
96ed6ff297 "libxlu: introduce xlu_pci_parse_spec_string()"
929f231140 "libxl: introduce 'libxl_pci_bdf' in the idl..."

Signed-off-by: Wei Liu <wl@xen.org>
2020-12-16 18:03:26 +00:00
Paul Durrant 96ed6ff297 libxlu: introduce xlu_pci_parse_spec_string()
This patch largely re-writes the code to parse a PCI_SPEC_STRING and enters
it via the newly introduced function. The new parser also deals with 'bdf'
and 'vslot' as non-positional paramaters, as per the documentation in
xl-pci-configuration(5).

The existing xlu_pci_parse_bdf() function remains, but now strictly parses
BDF values. Some existing callers of xlu_pci_parse_bdf() are
modified to call xlu_pci_parse_spec_string() as per the documentation in xl(1).

NOTE: Usage text in xl_cmdtable.c and error messages are also modified
      appropriately.
      As a side-effect this patch also fixes a bug where using '*' to specify
      all functions would lead to an assertion failure at the end of
      xlu_pci_parse_bdf().

Fixes: d25cc3ec93 ("libxl: workaround gcc 10.2 maybe-uninitialized warning")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2020-12-15 16:24:23 +00:00
Paul Durrant 6c2590967f xl: s/pcidev/pci where possible
To improve naming consistency, replaces occurrences of 'pcidev' with 'pci'.
The only remaining use of the term should be in relation to
'libxl_domain_config' where there are fields named 'pcidevs' and 'num_pcidevs'.

Purely cosmetic. No functional change.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2020-12-15 16:24:20 +00:00
Paul Durrant 812c8e01db xl: add 'mtu' option to network configuration
This patch adds code to parse a value for MTU from the network configuration
if it is present. The documentation in xl-network-configuration.5.pod is
also modified accordingly.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2020-08-27 10:04:25 +00:00
Marek Marczykowski-Górecki f76a0fa109 xl: add stubdomain related options to xl config parser
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Paul Durrant f18f8d9d63 libxl: make creation of xenstore 'suspend event channel' node optional...
... and, if it is not created, make the top level 'device' node in
xenstore writable by the guest instead.

The purpose and semantics of the suspend event channel node are explained
in xenstore-paths.pandoc [1]. It was originally introduced in xend by
commit 17636f47a4 "Teach xc_save to use event-channel-based domain
suspend if available.". Note that, because, the top-level frontend
'device' node was created writable by the guest in xend, there was no
need to explicitly create the 'suspend-event-channel' node as a writable
node.

However, libxl creates the 'device' node as read-only by the guest and so
explicit creation of the 'suspend-event-channel' node is necessary to make
it usable. This unfortunately has the side-effect of making some old
Windows PV drivers [2] cease to function. This is because they scan the top
level 'device' node, find the 'suspend' node and expect it to contain the
usual sub-nodes describing a PV frontend. When this is found not to be the
case, enumeration ceases and (because the 'suspend' node is observed before
the 'vbd' node) no system disk is enumerated. Windows will then crash with
bugcheck code 0x7B (missing system disk).

This patch adds a boolean 'xend_suspend_evtchn_compat' field into
libxl_create_info and a similarly named option in xl.cfg to set it.
If the value is true then the xenstore node is not created. Instead the
old xend behaviour of making top level device node writable by the guest is
re-instated. If the value is false (the default) then the current libxl
behaviour persists.

xenstore-paths.pandoc is also modified to say that the suspend event
channel node may not exist and, if it does not exist, then the guest may
create it. A note is also added concerning the writability of the top
level device node.

[1] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/xenstore-paths.pandoc;hb=HEAD#l177
[2] https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/5/html/para-virtualized_windows_drivers_guide/sect-para-virtualized_windows_drivers_guide-installing_and_configuring_the_para_virtualized_drivers-installing_the_para_virtualized_drivers

NOTE: While adding the new LIBXL_HAVE_CREATEINFO_... definition into
      libxl.h, this patch corrects the previous stanza which erroneously
      implies libxl_domain_create_info is a function.

Signed-off-by: Paul Durrant <paul@xen.org>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-03-19 15:56:54 +00:00
George Dunlap f2ae59bc4b Rationalize max_grant_frames and max_maptrack_frames handling
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>
Release-acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
2019-11-29 21:43:49 +00:00
Ian Jackson ad011ad088 libxl/xl: Overhaul passthrough setting logic
LIBXL_PASSTHROUGH_UNKNOWN (aka "ENABLED" in an earlier uncommitted
version of this code) is doing double duty.  We actually need all of
the following to be specifiable:
  * "default": enable PT iff we have devices to
    pass through specified in the initial config file.
  * "enabled" (and fail if the platform doesn't support it).
  * "disabled" (and reject future PT hotplug).
  * "share_pt"/"sync_pt": enable PT and set a specific PT mode.

Defaulting and error checking should be done in libxl.  So, we make
several changes here.

We introduce "enabled", and rename "unknown" to "default".

We move all of the error checking and defaulting code from xl into
libxl.  Now, libxl__domain_config_setdefault has all of the necessary
information to get this right.  So we can do it all there.  Choosing
the specific mode is arch-specific.

We can also arrange to have only one place each which calculates
(i) whether passthrough needs to be enabled because pt devices were
specified (ii) whether pt_share can be used (for each arch).

xl now only has to parse the enum in the same way as it parses all
other enums.

This change fixes a regression from earlier 4.13-pre: until recent
changes, passthrough was only enabled by default if passthrough
devices were specified.  We restore this behaviour.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien@xen.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Andrew Cooper <Andrew.Cooper3@citrix.com>
CC: Paul Durrant <pdurrant@gmail.com>
CC: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2019-10-24 16:08:41 +01:00
Ian Jackson 67c82f437e libxl: Move shadow_memkb and iommu_memkb defaulting into libxl
Defaulting is supposed to be done by libxl.  So these calculations
should be here in libxl.  libxl__domain_config_setdefault has all the
necessary information including the values of max_memkb and max_vcpus.

The overall functional effect depends on the caller:

For xl, no change.  The code moves from xl to libxl.

For callers who set one or both shadow_memkb and iommu_memkb (whether
from libxl_get_required_shadow_memory or otherwise) before calling
libxl_domain_need_memory (any version): the new code will leave their
setting(s) unchanged.

For callers who do not call libxl_domain_need_memory at all, and who
fail to set one of these memory values: now they are both are properly
set.  The shadow and iommu memory to be properly accounted for as
intended.

For callers which call libxl_domain_need_memory and request the
current API (4.13) or which track libxl, the default values are also
now right and everything works as intended.

For callers which call libxl_domain_need_memory, and request an old
pre-4.13 libxl API, and which leave one of these memkb settings unset,
we take special measures to preserve the old behaviour.

This means that they don't get the additional iommu memory and are at
risk of the domain running out of memory as a result of f89f555827
"remove late (on-demand) construction of IOMMU page tables".  But this
is no worse than the state just after f89f555827, which already
broke such callers in that way.  This is perhaps justifiable because
of the API stability warning next to libxl_domain_need_memory.

An alternative would be to drop the special-casing of these callers.
That would cause a discrepancy between libxl_domain_need_memory and
libxl_domain_create: the former would not include the iommu memory and
the latter would.  That seems worse, but it's debateable.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
2019-10-24 16:08:41 +01:00
Paul Durrant 4284b4163b libxl: replace 'enabled' with 'unknown' in libxl_passthrough enumeration
This is mostly a cosmetic patch to avoid the default enumeration value
being 'enabled'. The only non-cosmetic parts are in xl_parse.c where it now
becomes necessary to explicitly parse the 'enabled' value for xl.cfg
'passthrough' option, and error on the value 'unknown', because there is no
longer a direct mapping between valid xl.cfg values and the enumeration.

Suggested-by: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2019-10-02 16:54:32 +01:00