domain_getinfolist() is quadratic with the number of domains, because of the
behaviour of the underlying hypercall. xenopsd was further observed to be
wasting excessive quantites of time manipulating the list of already-obtained
domains.
Implement a tail recursive `rev_concat` equivalent to `concat |> rev`, and use
it instead of calling `@` multiple times.
An incidental benefit is that the list of domains will now be in domid order,
instead of having pairs of 2 domains changing direction every time.
In a scalability testing scenario with ~1000 VMs, a combination of this and
the subsequent change takes xenopsd's wallclock time in domain_getinfolist()
down from 88% to 0.02%
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Tested-by: Pau Ruiz Safont <pau.safont@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
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:
2ce11ce2496b2b9b3405
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>
Building with Dune in release mode fails with:
```
File "ocaml/xenstored/store.ml", line 464, characters 13-32:
Warning 18: this type-based record disambiguation is not principal.
File "ocaml/xenstored/store.ml", line 1:
Error: Some fatal warnings were triggered (1 occurrences)
```
This is a warning to help keep the code futureproof, quoting from its
documentation:
> Check information path during type-checking, to make sure that all types are
> derived in a principal way. When using labelled arguments and/or polymorphic
> methods, this flag is required to ensure future versions of the compiler will
> be able to infer types correctly, even if internal algorithms change. All
> programs accepted in -principal mode are also accepted in the default mode with
> equivalent types, but different binary signatures, and this may slow down type
> checking; yet it is a good idea to use it once before publishing source code.
Fixes: db471408ed "tools/ocaml/xenstored: Fix quota bypass on domain shutdown"
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Integers in Ocaml have 63 or 31 bits of signed precision.
On 64-bit builds of Ocaml, this is fine because a C uint32_t always fits
within a 63-bit signed integer.
In 32-bit builds of Ocaml, this goes wrong. The C uint32_t is truncated
first (loses the top bit), then has a unsigned/signed mismatch.
A "negative" value (i.e. a packet on the ring of between 1G and 2G in size)
will trigger an exception later in Bytes.make in xb.ml, and because the packet
is not removed from the ring, the exception re-triggers on every subsequent
query, creating a livelock.
Fix both the source of the exception in Xb, and as defence in depth, mark the
domain as bad for any Invalid_argument exceptions to avoid the risk of
livelock.
This is XSA-420 / CVE-2022-42324.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
XSA-322 fixed a domid reuse vulnerability by assigning Dom0 as the owner of
any nodes left after a domain is shutdown (e.g. outside its /local/domain/N
tree).
However Dom0 has no quota on purpose, so this opened up another potential
attack vector. Avoid it by deleting these nodes instead of assigning them to
Dom0.
This is part of XSA-419 / CVE-2022-42323.
Fixes: c46eff9212 ("tools/ocaml/xenstored: clean up permissions for dead domains")
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Introduce a limit on the number of outstanding reply packets in the xenbus
queue. This limits the number of in-flight requests: when the output queue is
full we'll stop processing inputs until the output queue has room again.
To avoid a busy loop on the Unix socket we only add it to the watched input
file descriptor set if we'd be able to call `input` on it. Even though Dom0
is trusted and exempt from quotas a flood of events might cause a backlog
where events are produced faster than daemons in Dom0 can consume them, which
could lead to an unbounded queue size and OOM.
Therefore the xenbus queue limit must apply to all connections, Dom0 is not
exempt from it, although if everything works correctly it will eventually
catch up.
This prevents a malicious guest from sending more commands while it has
outstanding watch events or command replies in its input ring. However if it
can cause the generation of watch events by other means (e.g. by Dom0, or
another cooperative guest) and stop reading its own ring then watch events
would've queued up without limit.
The xenstore protocol doesn't have a back-pressure mechanism, and doesn't
allow dropping watch events. In fact, dropping watch events is known to break
some pieces of normal functionality. This leaves little choice to safely
implement the xenstore protocol without exposing the xenstore daemon to
out-of-memory attacks.
Implement the fix as pipes with bounded buffers:
* Use a bounded buffer for watch events
* The watch structure will have a bounded receiving pipe of watch events
* The source will have an "overflow" pipe of pending watch events it couldn't
deliver
Items are queued up on one end and are sent as far along the pipe as possible:
source domain -> watch -> xenbus of target -> xenstore ring/socket of target
If the pipe is "full" at any point then back-pressure is applied and we prevent
more items from being queued up. For the source domain this means that we'll
stop accepting new commands as long as its pipe buffer is not empty.
Before we try to enqueue an item we first check whether it is possible to send
it further down the pipe, by attempting to recursively flush the pipes. This
ensures that we retain the order of events as much as possible.
We might break causality of watch events if the target domain's queue is full
and we need to start using the watch's queue. This is a breaking change in
the xenstore protocol, but only for domains which are not processing their
incoming ring as expected.
When a watch is deleted its entire pending queue is dropped (no code is needed
for that, because it is part of the 'watch' type).
There is a cache of watches that have pending events that we attempt to flush
at every cycle if possible.
Introduce 3 limits here:
* quota-maxwatchevents on watch event destination: when this is hit the
source will not be allowed to queue up more watch events.
* quota-maxoustanding which is the number of responses not read from the ring:
once exceeded, no more inputs are processed until all outstanding replies
are consumed by the client.
* overflow queue on the watch event source: all watches that cannot be stored
on destination are queued up here, a single command can trigger multiple
watches (e.g. due to recursion).
The overflow queue currently doesn't have an upper bound, it is difficult to
accurately calculate one as it depends on whether you are Dom0 and how many
watches each path has registered and how many watch events you can trigger
with a single command (e.g. a commit). However these events were already
using memory, this just moves them elsewhere, and as long as we correctly
block a domain it shouldn't result in unbounded memory usage.
Note that Dom0 is not excluded from these checks, it is important that Dom0 is
especially not excluded when it is the source, since there are many ways in
which a guest could trigger Dom0 to send it watch events.
This should protect against malicious frontends as long as the backend follows
the PV xenstore protocol and only exposes paths needed by the frontend, and
changes those paths at most once as a reaction to guest events, or protocol
state.
The queue limits are per watch, and per domain-pair, so even if one
communication channel would be "blocked", others would keep working, and the
domain itself won't get blocked as long as it doesn't overflow the queue of
watch events.
Similarly a malicious backend could cause the frontend to get blocked, but
this watch queue protects the frontend as well as long as it follows the PV
protocol. (Although note that protection against malicious backends is only a
best effort at the moment)
This is part of XSA-326 / CVE-2022-42318.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Ensures we cannot store more than [capacity] elements in a [Queue]. Replacing
all Queue with this module will then ensure at compile time that all Queues
are correctly bound checked.
Each element in the queue has a class with its own limits. This, in a
subsequent change, will ensure that command responses can proceed during a
flood of watch events.
No functional change.
This is part of XSA-326.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
The queue here would only ever hold at most one element. This will simplify
follow-up patches.
This is part of XSA-326.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
By default the OCaml garbage collector would return memory to the OS only
after unused memory is 5x live memory. Tweak this to 120% instead, which
would match the major GC speed.
This is part of XSA-326.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Previously we'd perform the operation, record the updated tree in the
transaction record, then try to insert a watchop path and the reply packet.
If we exceeded max requests we would've returned EQUOTA, but still:
* have performed the operation on the transaction's tree
* have recorded the watchop, making this queue effectively unbounded
It is better if we check whether we'd have room to store the operation before
performing the transaction, and raise EQUOTA there. Then the transaction
record won't grow.
This is part of XSA-326 / CVE-2022-42317.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
We currently have 2 different set of defaults in upstream Xen git tree:
* defined in the source code, only used if there is no config file
* defined in the oxenstored.conf.in upstream Xen
An oxenstored.conf file is not mandatory, and if missing, maxrequests in
particular has an unsafe default.
Resync the defaults from oxenstored.conf.in into the source code.
This is part of XSA-326 / CVE-2022-42316.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
During live update we will load the /tool/xenstored path from the previous binary,
and then try to mkdir /tool again which will fail with EEXIST.
Check for existence of the path before creating it.
The write call to /tool/xenstored should not need any changes
(and we do want to overwrite any previous path, in case it changed).
Prior to 7110192b1d live update would work only if the binary path was
specified, and with 7110192b1d and this live update also works when
no binary path is specified in `xenstore-control live-update`.
Fixes: 7110192b1d ("tools/oxenstored: Fix Oxenstored Live Update")
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Using a full path to the C libraries when preparing one of the ocaml
binding for those libraries make the binding unusable by external
project. The full path is somehow embedded and reused by the external
project when linking against the binding.
Instead, we will use the proper way to link a library, by using '-l'.
For in-tree build, we also need to provide the search directory via
'-L'.
(The search path -L are still be embedded, but at least that doesn't
prevent the ocaml binding from been used.)
Related-to: xen-project/xen#96
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
The current bindings function, but the preexisting
type physinfo_arch_cap_flag =
| X86 of x86_physinfo_arch_cap_flag
is a special case in the Ocaml type system with an unusual indirection, and
will break when a second option, e.g. `| ARM of ...` is added.
Also, the position the list is logically wrong. Currently, the types express
a list of elements which might be an x86 flag or an arm flag (and can
intermix), whereas what we actually want is either a list of x86 flags, or a
list of ARM flags (that cannot intermix).
Rework the Ocaml types to avoid the ABI special case and move the list
primitive, and adjust the C bindings to match.
Fixes: 2ce11ce249 ("x86/HVM: allow per-domain usage of hardware virtualized APIC")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Reposition the defines to match the outer style and to make the logic
half-legible.
No functional change.
Fixes: 0570d7f276 ("x86/msr: introduce an option for compatible MSR behavior selection")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Hiding the type will make it easier to change the implementation
in the future without breaking code that relies on it.
No functional change.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Fix compiler warning about:
* unused value
* ambiguous documentation comment
* non-principal type inference (compiler version dependent)
No functional change.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
paths.ml contains various paths known to configure, and currently is generated
via a Makefile rule. Simplify this and generate it through configure, similar
to how oxenstored.conf is generated from oxenstored.conf.in.
This will allow to reuse the generated file more easily with Dune.
No functional change.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Trying to include .ocamldep.make will cause it to be generated if it
doesn't exist.
We do not want this during make clean: we would remove it anyway.
Speeds up make clean.
Before (measured on f732240fd3, July 2022):
```
Parsing /home/edwin/xen2/tools/ocaml/libs/xl/../../../../tools/libs/light/libxl_types.idl
Parsing /home/edwin/xen2/tools/ocaml/libs/xl/../../../../tools/libs/light/libxl_types.idl
Parsing /home/edwin/xen2/tools/ocaml/libs/xl/../../../../tools/libs/light/libxl_types.idl
Parsing /home/edwin/xen2/tools/ocaml/libs/xl/../../../../tools/libs/light/libxl_types.idl
Parsing /home/edwin/xen2/tools/ocaml/libs/xl/../../../../tools/libs/light/libxl_types.idl
Performance counter stats for 'make clean -j8 -s' (5 runs):
4.2233 +- 0.0208 seconds time elapsed ( +- 0.49% )
```
After:
```
perf stat -r 5 --null make clean -j8 -s
Performance counter stats for 'make clean -j8 -s' (5 runs):
2.7325 +- 0.0138 seconds time elapsed ( +- 0.51% )
```
No functional change.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
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>
Add XEN_SYSCTL_PHYSCAP_X86_ASSISTED_XAPIC and
XEN_SYSCTL_PHYSCAP_X86_ASSISTED_X2APIC to report accelerated xAPIC and
x2APIC, on x86 hardware. This is so that xAPIC and x2APIC virtualization
can subsequently be enabled on a per-domain basis.
No such features are currently implemented on AMD hardware.
HW assisted xAPIC virtualization will be reported if HW, at the
minimum, supports virtualize_apic_accesses as this feature alone means
that an access to the APIC page will cause an APIC-access VM exit. An
APIC-access VM exit provides a VMM with information about the access
causing the VM exit, unlike a regular EPT fault, thus simplifying some
internal handling.
HW assisted x2APIC virtualization will be reported if HW supports
virtualize_x2apic_mode and, at least, either apic_reg_virt or
virtual_intr_delivery. This also means that
sysctl follows the conditionals in vmx_vlapic_msr_changed().
For that purpose, also add an arch-specific "capabilities" parameter
to struct xen_sysctl_physinfo.
Note that this interface is intended to be compatible with AMD so that
AVIC support can be introduced in a future patch. Unlike Intel that
has multiple controls for APIC Virtualization, AMD has one global
'AVIC Enable' control bit, so fine-graining of APIC virtualization
control cannot be done on a common interface.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jane Malalane <jane.malalane@citrix.com>
Reviewed-by: "Roger Pau Monné" <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.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>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
They are two competiting spelling for the variable holding the path to
"tools/ocaml", $(TOPLEVEL) and $(OCAML_TOPLEVEL). The "Makefile.rules"
which is included in all ocaml Makefiles have one rule which make use
of that variable which is then sometime unset. When building
"ocaml/xenstored", make isn't capable of generating ".ocamldep.make"
because $(TOPLEVEL) isn't defined in this case.
This can fail with an error like this when paths.ml have been
regenerated:
Error: Files define.cmx and paths.cmx
make inconsistent assumptions over interface Paths
This patch fix ".ocamldep.make" rule by always spelling the variable
$(OCAML_TOPLEVEL).
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Sadly, cpupool IDs are chosen by the caller, not assigned sequentially, so
this does need to have a full 32 bits of range.
Also leave a BUILD_BUG_ON() to catch more obvious ABI changes in the future.
Fixes: 92ea9c54fc ("arm/dom0less: assign dom0less guests to cpupools")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Such macro just clamps the passed version to fit in the designated
bits of the domctl field. The main purpose is to make it clearer in
the code when max grant version is being set in the grant_opts field.
Existing users that where setting the version in the grant_opts field
are switched to use the macro.
No functional change intended.
Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
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>
In order to let the toolstack be able to set the gnttab version on a
per-domain basis, it needs to know which ABIs Xen supports. Introduce
XEN_SYSCTL_PHYSCAP_gnttab_v{1,2} for the purpose, and plumb in down into
userspace.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Releae-Acked-by: Ian Jackson <iwj@xenproject.org>
This reverts commit 2075b410ee.
During the discussion [1] that took place after
the patch was merged it was agreed that it should
be reverted to avoid introducing a bad interface.
Furthermore, the patch rejected usage of flag
XEN_DOMCTL_CDF_vpci for x86 which is not true
as it should be set for dom0 PVH.
Due to XEN_DOMCTL_CDF_vpmu being introduced after
XEN_DOMCTL_CDF_vpci, modify its bit position
from 8 to 7.
[1] https://marc.info/?t=163354215300039&r=1&w=2
Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com<mailto:christian.lindig@citrix.com>>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
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>
Introduce flag XEN_SYSCTL_PHYSCAP_vpmu which
indicates whether the platform supports vPMU
functionality. Modify Xen and tools accordingly.
Take the opportunity and fix XEN_SYSCTL_PHYSCAP_vmtrace
definition in sysctl.h which wrongly use (1 << 6)
instead of (1u << 6).
Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Ian Jackson <iwj@xenproject.org>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Introduce XEN_DOMCTL_CDF_vpci flag to enable VPCI support in XEN.
Reject the use of this new flag for x86 as VPCI is not supported for
DOMU guests for x86.
Signed-off-by: Rahul Singh <rahul.singh@arm.com>
[stefano: drop _XEN_DOMCTL_CDF_vpci]
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
For log-dirty operations a 64-bit field is being truncated to become an
"int" return value. Seeing the large number of arguments the present
function takes, reduce its set of parameters to that needed for all
operations not involving the log-dirty bitmap, while introducing a new
wrapper for the log-dirty bitmap operations. This new function in turn
doesn't need an "mb" parameter, but has a 64-bit return type. (Using the
return value in favor of a pointer-type parameter is left as is, to
disturb callers as little as possible.)
While altering xc_shadow_control() anyway, also adjust the types of the
last two of the remaining parameters.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
Current unit8_t for pirq argument in this interface is too restrictive
causing failures on modern hardware with lots of GSIs. That extends down to
XEN_DOMCTL_irq_permission ABI structure where it needs to be fixed up
as well.
Internal Xen structures appear to be fine. Existing users of the interface
in tree (libxl, ocaml and python bindings) are currently using signed int
for pirq representation which should be wide enough. Converting them to
uint32_t now is desirable to avoid accidental passing of a negative
number (probably denoting an error code) by caller as pirq, but left for
the future clean up.
Domctl interface version is needed to be bumped with this change but that
was already done by 918b8842a8 ("arm64: Change type of hsr, cpsr, spsr_el1
to uint64_t") in this release cycle.
Additionally, take a change and convert allow_access argument to bool.
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
If PAGE_SIZE is already defined in the system (e.g. in /usr/include/limits.h
header) then gcc will trigger a redefinition error because of -Werror. This
patch replaces usage of PAGE_* macros with XC_PAGE_* macros in order to avoid
confusion between control domain page granularity (PAGE_* definitions) and
guest domain page granularity (which is what we are dealing with here).
Same issue applies for redefinitions of Val_none and Some_val macros which
can be already define in the OCaml system headers (e.g.
/usr/lib/ocaml/caml/mlvalues.h).
Signed-off-by: Costin Lupu <costin.lupu@cs.pub.ro>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
Tested-by: Dario Faggioli <dfaggioli@suse.com>
Instead of open coding the mapping of the p2m list use the already
existing xc_core_arch_map_p2m() call, especially as the current code
does not support guests with the linear p2m map. It should be noted
that this code is needed for colo/remus only.
Switching to xc_core_arch_map_p2m() drops the need to bail out for
bitness of tool stack and guest differing.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
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>
Due to how set_write_lowpath was used here it didn't detect create/delete
conflicts. When we create an entry we must mark our parent as modified
(this is what creating a new node via write does).
Otherwise we can have 2 transactions one creating, and another deleting a node
both succeeding depending on timing. Or one transaction reading an entry,
concluding it doesn't exist, do some other work based on that information and
successfully commit even if another transaction creates the node via mkdir
meanwhile.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
Watches on invalid paths were accepted, but they would never trigger. The
client also got no notification that its watch is bad and would never trigger.
Found again by the structured fuzzer, due to an error on live update reload:
the invalid watch paths would get rejected during live update and the list of
watches would be different pre/post live update.
The testcase is watch on `//`, which is an invalid path.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
We increment the domain's quota on mkdir even when the node already exists.
This results in a quota inconsistency after live update, where reconstructing
the tree from scratch results in a different quota.
Not a security issue because the domain uses up quota faster, so it will only
get a Quota error sooner than it should.
Found by the structured fuzzer.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
We're about to introduce support for Intel Processor Trace, but similar
functionality exists in other platforms.
Aspects of vmtrace can reasonably can be common, so start with
XEN_SYSCTL_PHYSCAP_vmtrace and plumb the signal from Xen all the way down into
`xl info`.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
This changes the output of xenstore-ls to be sorted. Previously the keys were
listed in the order in which they were inserted in. docs/misc/xenstore.txt
doesn't specify in what order keys are listed.
Map.update is used to retain semantics with replace_child: only an existing
child is replaced, if it wasn't part of the original map we don't add it.
Similarly exception behaviour is retained for del_childname and related
functions.
Entries are stored in reverse sort order, so that upon Map.fold the
constructed list is sorted in ascending order and there is no need for a
List.rev.
This changes the semantics and is not suitable as is for a backport. It
reveals bugs in buggy clients that depend on xenstore entry order, however
those clients should be fixed.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
We are currently on OCaml 4.02 as minimum version. To make the followup
optimizations compile backport these functions from OCaml 4.06.
This implementation is less efficient than the one in the 4.06 standard
library which has access to the internals of the Map.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
The code here is attempting to reduce memory usage by sharing common
substrings in the tree: it replaces strings with ints, and keeps a string->int
map that gets manually garbage collected using a hand-rolled mark and sweep
algorithm.
This is unnecessary: OCaml already has a mark-and-sweep Garbage Collector
runtime, and sharing of common strings in tree nodes can be achieved through
Weak references: if the string hasn't been seen yet it gets added to the Weak
reference table, and if it has we use the entry from the table instead, thus
storing a string only once. When the string is no longer referenced OCaml's
GC will drop it from the weak table: there is no need to manually do a
mark-and-sweep, or to tell OCaml when to drop it.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
One can specify the domid to use when creating the domain, but this was
hardcoded to 0.
Keep the existing `domain_create` function, and make domid an optional
argument. When not specified, default to 0.
Controlling the domid can be useful during testing or migration.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
There is a global history, containing transactions from the past 0.05s, which
get trimmed whenever any transaction commits or aborts. Destroying a domain
will cause xenopsd to perform some transactions deleting the tree, so that is
fine. But I think that a domain can abuse the xenbus reconnect facility to
cause a large history to be recorded - provided that noone does any
transactions on the system inbetween, which may be difficult to achieve given
squeezed's constant pinging.
The theoretical situation is like this:
- a domain starts a transaction, creates as large a tree as it can, commits
it. Then repeatedly:
- start a transaction, do nothing with it, start a transaction, delete
part of the large tree, write some new unique data there, don't commit
- cause a xenbus reconnect (I think this can be done by writing something
to the ring). This causes all transactions/watches for the connection to
be cleared, but NOT the history, there were no commits, so nobody
trimmed the history, i.e. it the history can contain transactions from
more than just 0.05s
- loop back and start more transactions, you can keep this up indefinitely
without hitting quotas
Now there is a periodic History.trim running every 0.05s, so I don't think you
can do much damage with it. But lets be safe an trim the transaction history
anyway on reconnect.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Edwin Török
Andrew Cooper
Anthony PERARD
Jane Malalane
Roger Pau Monné
Michal Orzel
Rahul Singh
Jan Beulich
Igor Druzhinin
Costin Lupu
Juergen Gross