Commit Graph
1646 Commits
Author SHA1 Message Date
Maximilian Engelhardt e18dadc5b7 docs: use predictable ordering in generated documentation
When the seq number is equal, sort by the title to get predictable
output ordering. This is useful for reproducible builds.

Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2020-12-22 13:36:58 +00:00
Luca Fancellu d81133d45d xen/arm: Add workaround for Cortex-A53 erratum #843419
On the Cortex A53, when executing in AArch64 state, a load or store instruction
which uses the result of an ADRP instruction as a base register, or which uses
a base register written by an instruction immediately after an ADRP to the
same register, might access an incorrect address.

The workaround is to enable the linker flag --fix-cortex-a53-843419
if present, to check and fix the affected sequence. Otherwise print a warning
that Xen may be susceptible to this errata

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2020-12-16 17:56:33 -08:00
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 e1141654c3 docs/man: modify xl-pci-configuration(5) to add 'name' field to PCI_SPEC_STRING
Since assignable devices can be named, a subsequent patch will support use
of a PCI_SPEC_STRING containing a 'name' parameter instead of a 'bdf'. In
this case the name will be used to look up the 'bdf' in the list of assignable
(or assigned) devices.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2020-12-15 16:24:34 +00:00
Paul Durrant f73c5dd56d docs/man: modify xl(1) in preparation for naming of assignable devices
A subsequent patch will introduce code to allow a name to be specified to
'xl pci-assignable-add' such that the assignable device may be referred to
by than name in subsequent operations.

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 8bc342b043 docs/man: fix xl(1) documentation for 'pci' operations
Currently the documentation completely fails to mention the existence of
PCI_SPEC_STRING. This patch tidies things up, specifically clarifying that
'pci-assignable-add/remove' take <BDF> arguments where as 'pci-attach/detach'
take <PCI_SPEC_STRING> arguments (which will be enforced in a subsequent
patch).

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 3085930e2f docs/man: improve documentation of PCI_SPEC_STRING...
... and prepare for adding support for non-positional parsing of 'bdf' and
'vslot' in a subsequent patch.

Also document 'BDF' as a first-class parameter type and fix the documentation
to state that the default value of 'rdm_policy' is actually 'strict', not
'relaxed', as can be seen in libxl__device_pci_setdefault().

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 581abb66a9 docs/man: extract documentation of PCI_SPEC_STRING from the xl.cfg manpage...
... and put it into a new xl-pci-configuration(5) manpage, akin to the
xl-network-configration(5) and xl-disk-configuration(5) manpages.

This patch moves the content of the section verbatim. A subsequent patch
will improve the documentation, once it is in its new location.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Acked-by: Wei Liu <wl@xen.org>
2020-12-15 16:24:23 +00:00
Juergen Gross 190ddd3403 tools/xenstore: allow special watches for privileged callers only
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>
2020-12-15 13:34:56 +01:00
Roger Pau Monne 881966dc3b docs: fix documentation about default scheduler
Fix the command line document to account for the default scheduler in
Kconfig being credit2 now, and the fact that it's selectable at build
time and thus different builds could end up with different default
schedulers.

Fixes: dafd936ddd ('Make credit2 the default scheduler')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
2020-12-07 15:44:52 +00:00
Igor Druzhinin b7c333016e x86/IRQ: allocate guest array of max size only for shareable IRQs
... and increase default "irq-max-guests" to 32.

It's not necessary to have an array of a size more than 1 for non-shareable
IRQs and it might impact scalability in case of high "irq-max-guests"
values being used - every IRQ in the system including MSIs would be
supplied with an array of that size.

Since it's now less impactful to use higher "irq-max-guests" value - bump
the default to 32. That should give more headroom for future systems.

Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2020-12-07 14:52:35 +01:00
Igor Druzhinin e373bc1bdc x86/IRQ: make max number of guests for a shared IRQ configurable
... and increase the default to 16.

Current limit of 7 is too restrictive for modern systems where one GSI
could be shared by potentially many PCI INTx sources where each of them
corresponds to a device passed through to its own guest. Some systems do not
apply due dilligence in swizzling INTx links in case e.g. INTA is declared as
interrupt pin for the majority of PCI devices behind a single router,
resulting in overuse of a GSI.

Introduce a new command line option to configure that limit and dynamically
allocate an array of the necessary size. Set the default size now to 16 which
is higher than 7 but could later be increased even more if necessary.

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2020-12-07 14:49:30 +01:00
Paul Durrant 1e83722add xl / libxl: add 'ex_processor_mask' into 'libxl_viridian_enlightenment'
Adding the new value into the enumeration makes it immediately available
to xl, so this patch adjusts the xl.cfg(5) documentation accordingly.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2020-12-04 13:16:22 +01:00
Diederik de Haas ba6e78f0db fix spelling errors
Only spelling errors; no functional changes.

In docs/misc/dump-core-format.txt there are a few more instances of
'informations'. I'll leave that up to someone who can properly determine
how those sentences should be constructed.

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
2020-12-04 08:28:21 +01:00
Juergen Gross cabf60fc32 docs: fix hypfs path documentation
The /params/* entry is missing a writable tag.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2020-12-02 10:13:52 +01:00
Bertrand Marquis fd7479b9ae xen/arm: Add workaround for Cortex-A55 erratum #1530923
On the Cortex A55, TLB entries can be allocated by a speculative AT
instruction. If this is happening during a guest context switch with an
inconsistent page table state in the guest, TLBs with wrong values might
be allocated.
The ARM64_WORKAROUND_AT_SPECULATE workaround is used as for erratum
1165522 on Cortex A76 or Neoverse N1.

This change is also introducing the MIDR identifier for the Cortex-A55.

Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Julien Grall <jgrall@amazon.com>
2020-11-25 11:17:27 +00:00
Jan Beulich 2291ad4775 ns16550: "com<N>=" command line options are x86-specific
Pure code motion (plus the addition of "#ifdef CONFIG_X86); no
functional change intended.

Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
2020-11-24 11:28:15 +01:00
Michal Orzel 22e323d115 xen/arm: Add workaround for Cortex-A76/Neoverse-N1 erratum #1286807
On the affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p0),
if a virtual address for a cacheable mapping of a location is being
accessed by a core while another core is remapping the virtual
address to a new physical page using the recommended break-before-make
sequence, then under very rare circumstances TLBI+DSB completes before
a read using the translation being invalidated has been observed by
other observers. The workaround repeats the TLBI+DSB operation for all
the TLB flush operations. While this is stricly not necessary, we don't
want to take any risk.

Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2020-11-18 15:21:24 +00:00
Penny Zheng 5505f5f8e7 xen/arm: Add Cortex-A73 erratum 858921 workaround
CNTVCT_EL0 or CNTPCT_EL0 counter read in Cortex-A73 (all versions)
might return a wrong value when the counter crosses a 32bit boundary.

Until now, there is no case for Xen itself to access CNTVCT_EL0,
and it also should be the Guest OS's responsibility to deal with
this part.

But for CNTPCT, there exists several cases in Xen involving reading
CNTPCT, so a possible workaround is that performing the read twice,
and to return one or the other depending on whether a transition has
taken place.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Wei Chen <Wei.Chen@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2020-11-11 13:44:33 -08:00
Olaf Hering 8aac8e0ef4 docs/xl: fix cpupool-cpu-remove
The cpu-pool must be specified.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Wei Liu <wl@xen.org>
2020-11-06 16:03:18 +00:00
Michal Orzel f776e5fb3e xen/arm: Document the erratum #853709 related to Cortex A72
The Cortex-A72 erratum #853709 is the same as the Cortex-A57
erratum #852523. As the latter is already workaround, we only
need to update the documentation.

Signed-off-by: Michal Orzel <michal.orzel@arm.com>
[julieng: Reworded the commit message]
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
2020-10-14 18:02:50 +01:00
Trammell Hudson 8a71d50ed4 efi: Enable booting unified hypervisor/kernel/initrd images
This patch adds support for bundling the xen.efi hypervisor, the xen.cfg
configuration file, the Linux kernel and initrd, as well as the XSM,
and architectural specific files into a single "unified" EFI executable.
This allows an administrator to update the components independently
without requiring rebuilding xen, as well as to replace the components
in an existing image.

The resulting EFI executable can be invoked directly from the UEFI Boot
Manager, removing the need to use a separate loader like grub as well
as removing dependencies on local filesystem access.  And since it is
a single file, it can be signed and validated by UEFI Secure Boot without
requring the shim protocol.

It is inspired by systemd-boot's unified kernel technique and borrows the
function to locate PE sections from systemd's LGPL'ed code.  During EFI
boot, Xen looks at its own loaded image to locate the PE sections for
the Xen configuration (`.config`), dom0 kernel (`.kernel`), dom0 initrd
(`.ramdisk`), and XSM config (`.xsm`), which are included after building
xen.efi using objcopy to add named sections for each input file.

For x86, the CPU ucode can be included in a section named `.ucode`,
which is loaded in the efi_arch_cfg_file_late() stage of the boot process.

On ARM systems the Device Tree can be included in a section named
`.dtb`, which is loaded during the efi_arch_cfg_file_early() stage of
the boot process.

Note that the system will fall back to loading files from disk if
the named sections do not exist. This allows distributions to continue
with the status quo if they want a signed kernel + config, while still
allowing a user provided initrd (which is how the shim protocol currently
works as well).

This patch also adds constness to the section parameter of
efi_arch_cfg_file_early() and efi_arch_cfg_file_late(),
changes pe_find_section() to use a const CHAR16 section name,
and adds pe_name_compare() to match section names.

Signed-off-by: Trammell Hudson <hudson@trmm.net>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
[Fix ARM build by including pe.init.o]
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
2020-10-09 17:20:11 +01:00
Juergen Gross c65687ed16 tools/xenstore: remove socket-only option from xenstore client
The Xenstore access commands (xenstore-*) have the possibility to limit
connection to Xenstore to a local socket (option "-s"). This is an
option making no sense at all, as either there is only a socket, so
the option would be a nop, or there is no socket at all (in case
Xenstore is running in a stubdom or the client is called in a domU),
so specifying the option would just lead to failure.

So drop that option completely.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-10-08 12:47:50 +00:00
Paul Durrant 707eb41ae2 xl: implement documented '--force' option for block-detach
The manpage for 'xl' documents an option to force a block device to be
released even if the domain to which it is attached does not co-operate.
The documentation also states that, if the force flag is not specified, the
block-detach operation should fail.

Currently the force option is not implemented and a non-forced block-detach
will auto-force after a time-out of 10s. This patch implements the force
option and also stops auto-forcing a non-forced block-detach by calling
libxl_device_disk_safe_remove() rather than libxl_device_disk_remove(),
allowing the operation to fail cleanly as per the documented behaviour.

NOTE: The documentation is also adjusted since the normal positioning of
      options is before compulsory parameters. It is also noted that use of
      the --force option may lead to a guest crash.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2020-10-01 09:32:57 +00:00
Julien Grall 1814a626fb xen/arm: Update silicon-errata.txt with the Neovers AT erratum
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>
2020-09-04 18:01:40 +01:00
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
Paul Durrant f9d25fa3fa public/io/netif: specify MTU override node
There is currently no documentation to state what MTU a frontend should
adertise to its network stack. It has however long been assumed that the
default value of 1500 is correct.

This patch specifies a mechanism to allow the tools to set the MTU via a
xenstore node in the frontend area and states that the absence of that node
means the frontend should assume an MTU of 1500 octets.

NOTE: The Windows PV frontend has used an MTU sampled from the xenstore
      node specified in this patch.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Wei Liu <wl@xen.org>
2020-08-27 10:03:54 +00:00
Ian Jackson eee588bd73 docs/process/branching-checklist: Get osstest branch right
The runes for this manual osstest were wrong.  It needs to run as
osstest, and cr-for-branches should be run from testing.git.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-08-18 13:40:18 +01:00
Roger Pau Monne 1ee1441835 print: introduce a format specifier for pci_sbdf_t
The new format specifier is '%pp', and prints a pci_sbdf_t using the
seg:bus:dev.func format. Replace all SBDFs printed using
'%04x:%02x:%02x.%u' to use the new format specifier.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Julien Grall <julien.grall@arm.com>
For just the pieces where Jan is the only maintainer:
Acked-by: Jan Beulich <jbeulich@suse.com>
2020-07-28 19:33:28 +01:00
Andrew Cooper 9ffdda96d9 docs: Replace non-UTF-8 character in hypfs-paths.pandoc
From the docs cronjob on xenbits:

  /usr/bin/pandoc --number-sections --toc --standalone misc/hypfs-paths.pandoc --output html/misc/hypfs-paths.html
  pandoc: Cannot decode byte '\x92': Data.Text.Internal.Encoding.decodeUtf8: Invalid UTF-8 stream
  make: *** [Makefile:236: html/misc/hypfs-paths.html] Error 1

Fixes: 5a4a411bde ("docs: specify stability of hypfs path documentation")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-07-20 18:08:00 +01:00
Juergen Gross 5a4a411bde docs: specify stability of hypfs path documentation
In docs/misc/hypfs-paths.pandoc the supported paths in the hypervisor
file system are specified. Make it more clear that path availability
might change, e.g. due to scope widening or narrowing (e.g. being
limited to a specific architecture).

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-07-20 13:38:00 +02:00
Ian Jackson 3df0424e69 Branch Xen 4.15: Change version numbers
And rerun autogen.sh.  No changes other than to versions.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-07-13 14:50:06 +01:00
Julien Grall 02d69864b5 pvcalls: Document correctly and explicitely the padding for all arches
The specification of pvcalls suggests there is padding for 32-bit x86 at
the end of most the structure. However, they are not described in in the
public header.

Because of that all the structures would have a different size between
32-bit x86 and 64-bit x86.

For all the other architectures supported (Arm and 64-bit x86), the
structure have the sames sizes because they contain implicit padding
thanks to the 64-bit alignment of the field uint64_t field.

Given the specification is authoritative, the padding will now be the
same for all architectures. The potential breakage of compatibility is
ought to be fine as pvcalls is still a tech preview.

Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Paul Durrant <paul@xen.org>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
2020-07-10 09:52:24 -07:00
Ian Jackson 4f4f6a67ac tools: Commit autoconf output from Debian buster
These files are in tree so that people can build (including from git)
without needing recent autotools.

We should update them periodically.  Debian buster has been Debian
stable fopr a while.  Our CI is running buster.

There should be no significant functional change; it's possible that
there are bugfixes to the configure scripts but I have not reviewed
them.

These files were last changed in
  83c845033d
  libxl: use vchan for QMP access with Linux stubdomain
where a new feature was added.  However, that commit contains a lot of
extraneous noise in configure compared to its parent.

Compared to 83c845033dc8bb3a35ae245effb7832b6823174a~, this commit
restores those extraneous changes, leaving precisely the correct
changes.  So one way of looking at the changes we are making now, is
that we are undoing accidental changes to the autoconf output.

I used Debian's autoconf 2.69-11 on amd64.

CC: Wei Liu <wl@xen.org>
CC: Nick Rosbrook <rosbrookn@gmail.com>
Reported-by: Nick Rosbrook <rosbrookn@gmail.com>
CC: Paul Durrant <paul@xen.org>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-06-19 16:19:59 +01:00
Jason Andryuk f0dca895a5 xl: Allow shutdown wait for domain death
`xl shutdown -w` waits for the first of either domain shutdown or death.
Shutdown is the halting of the guest operating system, and death is the
freeing of domain resources.

Allow specifying -w multiple times to wait for only domain death.  This
is useful in scripts so that all resources are free before the script
continues.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-06-18 16:58:56 +01:00
Andrew Cooper 71ca0e0ad0 x86/spec-ctrl: Hide RDRAND by default on IvyBridge client
To combat the absence of mitigating microcode, arrange to hide RDRAND by
default on IvyBridge client hardware.

Adjust the default feature derivation to hide RDRAND on IvyBridge client
parts, unless `cpuid=rdrand` is explicitly provided.

Adjust the restore path in xc_cpuid_apply_policy() to not hide RDRAND from VMs
which migrated from pre-4.14.

In all cases, individual guests can continue using RDRAND if explicitly
enabled in their config files.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-06-17 13:54:12 +01:00
Andrew Cooper 10ea4e417b docs: Minor build improvements
Don't use "set -x" for the figs rule.  It doesn't take effect in the recursive
make environment.

Turn the HTML manpage comments into makefile comments, not shell comments.
This saves 3x shell invocations per manpage.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-06-11 17:19:26 +01:00
Andrew Cooper 7028534d84 x86/spec-ctrl: Update docs with SRBDS workaround
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>
2020-06-11 16:26:06 +01:00
Andrew Cooper 6a49b9a792 x86/spec-ctrl: Mitigate the Special Register Buffer Data Sampling sidechannel
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>
2020-06-09 17:42:18 +01:00
Andrew Cooper caab85ab58 x86/spec-ctrl: CPUID/MSR definitions for Special Register Buffer Data Sampling
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>
Acked-by: Wei Liu <wl@xen.org>
2020-06-09 17:42:18 +01:00
Ian Jackson 1a58d8dab5 docs-parse-support-md: Cope with buster's pandoc
Provide the implementation for newer pandoc json.

I have done an adhoc test and this now works on both buster and
stretch and seems to produce the expected support matrix when run
using the example rune (which processes unstable and 4.11).

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-06-09 14:05:49 +01:00
Ian Jackson 31a714d54f docs-parse-support-md: Prepare for coping with pandoc versions
Different pandoc versions generate, and expect, a different toplevel
structure for their json output and inpout.  Newer pandoc's toplevel
is a hash.  We are going to want to support this.  We can tell what
kind of output we should produce by looking at the input we got (which
itself came from pandoc).  So:

 * Make space for code to read toplevel objects which are not arrays.
   Currently this code is absent and we just die explicitly (rather
   than dying because we tried to use a hashref as an array ref).

 * Move generation of the toplevel json structure out of
   pandoc2html_inline, and abstract it away through a subref which is
   set up when we read the input file.

This is just prep work.  No functional change other than a change to
an error message.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-06-09 14:05:49 +01:00
Andrew Cooper 11ba5cdb84 docs/support-matrix: unbreak docs rendering
The cronjob which renders https://xenbits.xen.org/docs/ has been broken for a
while.  commitish_version() pulls an old version of xen/Makefile out of
history, and uses the xenversion rule.

Currently, this fails with:

  tmp.support-matrix.xen.make:130: scripts/Kbuild.include: No such file or directory

which is because the Makefile legitimately references Kbuild.include with a
relative rather than absolute path.

Rework support-matrix-generate to use sed to extract the major/minor version,
rather than expecting xen/Makefile to be usable in a different tree.

Fixes: 945e80a730 ("docs: Provide support-matrix-generate, to generate a support matrix in HTML")
Backport: 4.11+
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
2020-06-08 15:19:49 +01:00
Andrew Cooper 99a76a88d5 docs/ucode: Extend runtime microcode loading documentation
Extend the disclaimer about runtime loading.  While we've done our best to
make the mechaism reliable, the safety of late loading does ultimately depend
on the contents of the blobs.

Extend the xen-ucode portion with examples of how to use it.

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: Paul Durrant <paul@xen.org>
---
CC: George Dunlap <George.Dunlap@eu.citrix.com>
CC: Ian Jackson <ian.jackson@citrix.com>
CC: Jan Beulich <JBeulich@suse.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Wei Liu <wl@xen.org>
CC: Julien Grall <julien@xen.org>
CC: Paul Durrant <paul@xen.org>
2020-06-02 19:18:44 +01:00
Andrew Cooper b60ab42db2 x86/shstk: Activate Supervisor Shadow Stacks
With all other plumbing in place, activate shadow stacks when possible.

Note that CET shares the similar problems to SMEP/SMAP with Ring1 being
supervisor to the processor, and that the layout of the shadow stack differs
between an IRET to Ring 1 and Ring 3.  Therefore, we disable PV32 when CET is
enabled.  Compatibility can be maintained if necessary via PV-Shim.

The BSP needs to wait until alternatives have run (to avoid interaction with
CR0.WP), and after the first reset_stack_and_jump() to avoid having a pristine
shadow stack interact in problematic ways with an in-use regular stack.
Activate shadow stack in reinit_bsp_stack().

APs have all infrastructure set up by the booting CPU, so enable shadow stacks
before entering C.  Adjust the logic to call start_secondary rather than jump
to it, so stack traces make more sense.

The crash path needs to turn CET off to avoid interfering with the crash
kernel's environment.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2020-05-29 23:09:46 +01:00
Andrew Cooper d3fb3ed32f x86/shstk: Introduce Supervisor Shadow Stack support
Introduce CONFIG_HAS_AS_CET_SS to determine whether CET Shadow Stack
instructions are supported in the assembler, and CONFIG_XEN_SHSTK as the main
build option.

Introduce cet={no-,}shstk to for a user to select whether or not to use shadow
stacks at runtime, and X86_FEATURE_XEN_SHSTK to determine Xen's overall
enablement of shadow stacks.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2020-05-29 23:09:46 +01:00
Dario Faggioli 8e2aa76dc1 xen: credit2: limit the max number of CPUs in a runqueue
In Credit2 CPUs (can) share runqueues, depending on the topology. For
instance, with per-socket runqueues (the default) all the CPUs that are
part of the same socket share a runqueue.

On platform with a huge number of CPUs per socket, that could be a
problem. An example is AMD EPYC2 servers, where we can have up to 128
CPUs in a socket.

It is of course possible to define other, still topology-based, runqueue
arrangements (e.g., per-LLC, per-DIE, etc). But that may still result in
runqueues with too many CPUs on other/future platforms. For instance, a
system with 96 CPUs and 2 NUMA nodes will end up having 48 CPUs per
runqueue. Not as bad, but still a lot!

Therefore, let's set a limit to the max number of CPUs that can share a
Credit2 runqueue. The actual value is configurable (at boot time), the
default being 16. If, for instance,  there are more than 16 CPUs in a
socket, they'll be split among two (or more) runqueues.

Note: with core scheduling enabled, this parameter sets the max number
of *scheduling resources* that can share a runqueue. Therefore, with
granularity set to core (and assumint 2 threads per core), we will have
at most 16 cores per runqueue, which corresponds to 32 threads. But that
is fine, considering how core scheduling works.

Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2020-05-29 18:53:54 +01:00
Andrew Cooper 17a68b8a66 docs/xl.cfg: Rewrite cpuid= section
This is partly to adjust the description of 'k' and 's' seeing as they have
changed, but mostly restructuring the information for clarity.

In particular, use indentation to clearly separate the areas discussing libxl
format from xend format.  In addition, extend the xend format section to
discuss subleaf notation.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-29 17:33:03 +01:00
Andrew Cooper ddd273d886 docs/migration: Specify X86_{CPUID,MSR}_POLICY records
These two records move blobs from the XEN_DOMCTL_{get,set}_cpu_policy
hypercall.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-29 17:33:03 +01:00
Andrew Cooper 6f71b5b150 docs/migration Specify migration v3 and STATIC_DATA_END
Migration data can be split into two parts - that which is invariant of
guest execution, and that which is not.  Separate these two with the
STATIC_DATA_END record.

The short term, we want to move the x86 CPU Policy data into the stream.
In the longer term, we want to provisionally send the static data only
to the destination as a more robust compatibility check.  In both cases,
we will want a callback into the higher level toolstack.

Mandate the presence of the STATIC_DATA_END record, and declare this v3,
along with instructions for how to compatibly interpret a v2 stream.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-29 17:33:03 +01:00