Commit Graph
299 Commits
Author SHA1 Message Date
Andrew Cooper 620f413ecf x86/sysctl: Retrofit XEN_SYSCTL_cpu_featureset_{pv,hvm}_max
Featuresets are supposed to be disappearing when the CPU policy infrastructure
is complete, but that has taken longer than expected, and isn't going to be
complete imminently either.

In the meantime, Xen does have proper default/max featuresets, and xen-cpuid
can even get them via the XEN_SYSCTL_cpu_policy_* interface, but only knows
now to render them nicely via the featureset interface.

Differences between default and max are a frequent source of errors,
frequently too in secret leading up to an embargo, so extend the featureset
sysctl to allow xen-cpuid to render them all nicely.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
(cherry picked from commit 433d012c6c)
2023-08-08 16:02:53 +01:00
Andrew Cooper 1b6acdeeb2 tools/ocaml/libs: Fix memory/resource leaks with caml_alloc_custom()
All caml_alloc_*() functions can throw exceptions, and longjump out of
context.  If this happens, we leak the xch/xce handle.

Reorder the logic to allocate the the Ocaml object first.

Fixes: 8b3c06a3e5 ("tools/ocaml/xenctrl: OCaml 5 support, fix use-after-free")
Fixes: 22d5affdf0 ("tools/ocaml/evtchn: OCaml 5 support, fix potential resource leak")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit d69ccf52ad)
2023-02-09 15:58:51 +00:00
Andrew Cooper 1fdff77e26 tools/ocaml/xc: Don't reference Abstract_Tag objects with the GC lock released
The intf->{addr,len} references in the xc_map_foreign_range() call are unsafe.
From the manual:

  https://ocaml.org/manual/intfc.html#ss:parallel-execution-long-running-c-code

"After caml_release_runtime_system() was called and until
caml_acquire_runtime_system() is called, the C code must not access any OCaml
data, nor call any function of the run-time system, nor call back into OCaml
code."

More than what the manual says, the intf pointer is (potentially) invalidated
by caml_enter_blocking_section() if another thread happens to perform garbage
collection at just the right (wrong) moment.

Rewrite the logic.  There's no need to stash data in the Ocaml object until
the success path at the very end.

Fixes: 8b7ce06a2d ("ocaml: Add XC bindings.")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 9e7c74e6f9)
2023-02-09 15:58:51 +00:00
Edwin Török 854013084e tools/ocaml/xc: Fix binding for xc_domain_assign_device()
The patch adding this binding was plain broken, and unreviewed.  It modified
the C stub to add a 4th parameter without an equivalent adjustment in the
Ocaml side of the bindings.

In 64bit builds, this causes us to dereference whatever dead value is in %rcx
when trying to interpret the rflags parameter.

This has gone unnoticed because Xapi doesn't use this binding (it has its
own), but unbreak the binding by passing RDM_RELAXED unconditionally for
now (matching the libxl default behaviour).

Fixes: 9b34056cb4 ("tools: extend xc_assign_device() to support rdm reservation policy")
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 4250683842)
2023-02-09 15:58:51 +00:00
Edwin Török e18faeb91e tools/ocaml/evtchn: Don't reference Custom objects with the GC lock released
The modification to the _H() macro for Ocaml 5 support introduced a subtle
bug.  From the manual:

  https://ocaml.org/manual/intfc.html#ss:parallel-execution-long-running-c-code

"After caml_release_runtime_system() was called and until
caml_acquire_runtime_system() is called, the C code must not access any OCaml
data, nor call any function of the run-time system, nor call back into OCaml
code."

Previously, the value was a naked C pointer, so dereferencing it wasn't
"accessing any Ocaml data", but the fix to avoid naked C pointers added a
layer of indirection through an Ocaml Custom object, meaning that the common
pattern of using _H() in a blocking section is unsafe.

In order to fix:

 * Drop the _H() macro and replace it with a static inline xce_of_val().
 * Opencode the assignment into Data_custom_val() in the two constructors.
 * Rename "value xce" parameters to "value xce_val" so we can consistently
   have "xenevtchn_handle *xce" on the stack, and obtain the pointer with the
   GC lock still held.

Fixes: 22d5affdf0 ("tools/ocaml/evtchn: OCaml 5 support, fix potential resource leak")
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 2636d8ff7a)
2023-02-09 15:58:51 +00:00
Andrew Cooper 6d66fb984c tools/ocaml/libs: Allocate the correct amount of memory for Abstract_tag
caml_alloc() takes units of Wsize (word size), not bytes.  As a consequence,
we're allocating 4 or 8 times too much memory.

Ocaml has a helper, Wsize_bsize(), but it truncates cases which aren't an
exact multiple.  Use a BUILD_BUG_ON() to cover the potential for truncation,
as there's no rounding-up form of the helper.

Fixes: 8b7ce06a2d ("ocaml: Add XC bindings.")
Fixes: d3e649277a ("ocaml: add mmap bindings implementation.")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 36eb2de31b)
2023-02-09 15:58:51 +00:00
Edwin Török 552e5f28d4 tools/ocaml/libs: Don't declare stubs as taking void
There is no such thing as an Ocaml function (C stub or otherwise) taking no
parameters.  In the absence of any other parameters, unit is still passed.

This doesn't explode with any ABI we care about, but would malfunction for an
ABI environment such as stdcall.

Fixes: c3afd398ba ("ocaml: Add XS bindings.")
Fixes: 8b7ce06a2d ("ocaml: Add XC bindings.")
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit ff8b560be8)
2023-02-09 15:58:51 +00:00
Edwin Török f7c4fab9b5 tools/ocaml/xb: Drop Xs_ring.write
This function is unusued (only Xs_ring.write_substring is used), and the
bytes/string conversion here is backwards: the C stub implements the bytes
version and then we use a Bytes.unsafe_of_string to convert a string into
bytes.

However the operation here really is read-only: we read from the string and
write it to the ring, so the C stub should implement the read-only string
version, and if needed we could use Bytes.unsafe_to_string to be able to send
'bytes'. However that is not necessary as the 'bytes' version is dropped above.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 01f139215e)
2023-02-09 15:58:51 +00:00
Edwin Török 049d16c8ce tools/ocaml/xb,mmap: Use Data_abstract_val wrapper
This is not strictly necessary since it is essentially a no-op currently: a
cast to void * and value *, even in OCaml 5.0.

However it does make it clearer that what we have here is not a regular OCaml
value, but one allocated with Abstract_tag or Custom_tag, and follows the
example from the manual more closely:
https://v2.ocaml.org/manual/intfc.html#ss:c-outside-head

It also makes it clearer that these modules have been reviewed for
compat with OCaml 5.0.

We cannot use OCaml finalizers here, because we want exact control over when
to unmap these pages from remote domains.

No functional change.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit d2ccc63711)
2023-02-09 15:58:51 +00:00
Edwin Török 8c66a2d88a tools/ocaml/xenctrl: Use larger chunksize in domain_getinfolist
domain_getinfolist() is quadratic with the number of domains, because of the
behaviour of the underlying hypercall.  Nevertheless, getting domain info in
blocks of 1024 is far more efficient than blocks of 2.

In a scalability testing scenario with ~1000 VMs, a combination of this and
the previous 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>
(cherry picked from commit 95db09b1b1)
2023-02-09 15:58:51 +00:00
Edwin Török c6a3d14df0 tools/ocaml/xenctrl: Make domain_getinfolist tail recursive
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>
(cherry picked from commit c3b6be714c)
2023-02-09 15:58:51 +00:00
Edwin Török c96f51bc3e tools/ocaml/evtchn: Extend the init() binding with a cloexec flag
For live update, oxenstored wants to clear CLOEXEC on the evtchn handle, so it
survives the execve() into the new oxenstored.

Have the new interface match how cloexec works in other Ocaml standard
libraries.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 9bafe4a533)
2022-12-12 11:04:12 +00:00
Edwin Török dd3006b1dd tools/ocaml/evtchn: Add binding for xenevtchn_fdopen()
For live update, the new oxenstored needs to reconstruct an evtchn object
around an existing file descriptor.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 7ba68a6c55)
2022-12-12 11:04:12 +00:00
Edwin Török 5e41efcc50 tools/ocaml/evtchn: OCaml 5 support, fix potential resource leak
There is no binding for xenevtchn_close().  In principle, this is a resource
leak, but the typical usage is as a singleton that lives for the lifetime of
the program.

Ocaml 5 no longer permits storing a naked C pointer in an Ocaml value.

Therefore, use a Custom block.  This allows us to use the finaliser callback
to call xenevtchn_close(), if the Ocaml object goes out of scope.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 22d5affdf0)
2022-12-12 11:04:12 +00:00
Edwin Török 635390415f tools/ocaml: Ensure packet size is never negative
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>
(cherry picked from commit ae34df4d82)
2022-11-01 14:07:24 +00:00
Edwin Török cec3c52c28 tools/ocaml: Limit maximum in-flight requests / outstanding replies
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>
(cherry picked from commit 9284ae0c40)
2022-11-01 14:07:24 +00:00
Edwin Török ea1567893b tools/ocaml/xb: Add BoundedQueue
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>
(cherry picked from commit 19171fb5d8)
2022-11-01 14:07:24 +00:00
Edwin Török 59981b08c8 tools/ocaml: Change Xb.input to return Packet.t option
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>
(cherry picked from commit c0a86a4627)
2022-11-01 14:07:24 +00:00
Edwin Török 8b60ad49b4 tools/ocaml/libs/xb: hide type of Xb.t
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>
(cherry picked from commit 7ade30a145)
2022-11-01 14:07:24 +00:00
Roger Pau Monné 2abeaf319c domctl: introduce a macro to set the grant table max version
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>
2021-11-17 08:12:00 +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
Andrew Cooper b36c23eada xen: Report grant table v1/v2 capabilities to the toolstack
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>
2021-11-08 15:09:16 +00:00
Michal Orzel 9516d01ac3 Revert "xen/domctl: Introduce XEN_DOMCTL_CDF_vpci flag"
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>
2021-10-14 10:08:07 +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
Michal Orzel 3b38b1d964 xen+tools: Introduce XEN_SYSCTL_PHYSCAP_vpmu
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>
2021-10-12 14:50:45 -07:00
Rahul Singh 2075b410ee xen/domctl: Introduce XEN_DOMCTL_CDF_vpci flag
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>
2021-10-07 12:47:25 -07:00
Jan Beulich 2107cc76db libxc: split xc_logdirty_control() from xc_shadow_control()
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>
2021-09-03 15:09:48 +02:00
Igor Druzhinin 73c932d0ea tools/libxc: use uint32_t for pirq in xc_domain_irq_permission
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>
2021-07-26 10:32:04 +01:00
Costin Lupu 2d1a35f1e6 tools/ocaml: Fix redefinition errors
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>
2021-07-09 16:00:09 +01:00
Juergen Gross f183854fac tools/libs/ctrl: use common p2m mapping code in xc_domain_resume_any()
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>
2021-06-04 18:56:46 +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
Andrew Cooper a48066d25c xen+tools: Introduce XEN_SYSCTL_PHYSCAP_vmtrace
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>
2021-01-30 03:21:33 +00:00
Edwin Török 4522321ced tools/ocaml/libs/xc: Backward compatible domid control at domain creation time
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>
2021-01-22 18:01:34 +00:00
Edwin Török 5e31789634 tools/ocaml/libs/xb: Do not crash after xenbus is unmapped
Xenmmap.unmap sets the address to MAP_FAILED in xenmmap_stubs.c.  If due to a
bug there were still references to the Xenbus and we attempt to use it then we
crash.  Raise an exception instead of crashing.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2021-01-22 14:40:29 +00:00
Manuel Bouyer cf2a566060 ocaml/libs/eventchn: drop unneeded evtchn.h
On NetBSD xen/sys/evtchn.h is not available any more. Just remove it as it's
not needed.

Signed-off-by: Manuel Bouyer <bouyer@netbsd.org>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2021-01-18 17:55:27 +00:00
Paul Durrant c00da82355 libxl: add libxl_device_pci_assignable_list_free()...
... to be used by callers of libxl_device_pci_assignable_list().

Currently there is no API for callers of libxl_device_pci_assignable_list()
to free the list. The xl function pciassignable_list() calls
libxl_device_pci_dispose() on each element of the returned list, but
libxl_pci_assignable() in libxl_pci.c does not. Neither does the implementation
of libxl_device_pci_assignable_list() call libxl_device_pci_init().

This patch adds the new API function, makes sure it is used everywhere and
also modifies libxl_device_pci_assignable_list() to initialize list
entries rather than just zeroing them.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Acked-by: Wei Liu <wl@xen.org>
2020-12-15 16:24:23 +00:00
Edwin Török bf0703992c tools/ocaml/xenstored: Fix path length validation
Currently, oxenstored checks the length of paths against 1024, then
prepends "/local/domain/$DOMID/" to relative paths.  This allows a domU
to create paths which can't subsequently be read by anyone, even dom0.
This also interferes with listing directories, etc.

Define a new oxenstored.conf entry: quota-path-max, defaulting to 1024
as before.  For paths that begin with "/local/domain/$DOMID/" check the
relative path length against this quota. For all other paths check the
entire path length.

This ensures that if the domid changes (and thus the length of a prefix
changes) a path that used to be valid stays valid (e.g. after a
live-migration).  It also ensures that regardless how the client tries
to access a path (domid-relative or absolute) it will get consistent
results, since the limit is always applied on the final canonicalized
path.

Delete the unused Domain.get_path to avoid it being confused with
Connection.get_path (which differs by a trailing slash only).

Rewrite Util.path_validate to apply the appropriate length restriction
based on whether the path is relative or not.  Remove the check for
connection_path being absolute, because it is not guest controlled data.

This is part of XSA-323.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-12-15 13:36:39 +01:00
Juergen Gross 4664034cdc tools/libs: move official headers to common directory
Instead of each library having an own include directory move the
official headers to tools/include instead. This will drop the need to
link those headers to tools/include and there is no need any longer
to have library-specific include paths when building Xen.

While at it remove setting of the unused variable
PKG_CONFIG_CFLAGS_LOCAL in libs/*/Makefile.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Tested-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
2020-10-23 15:50:51 +01:00
Andrew Cooper dbe399b174 xen/domctl: Introduce and use XEN_DOMCTL_CDF_nested_virt
Like other major areas of functionality, nested virt (or not) needs to be
known at domain creation time for sensible CPUID handling, and wants to be
known this early for sensible infrastructure handling in Xen.

Introduce XEN_DOMCTL_CDF_nested_virt and modify libxl to set it appropriately
when creating domains.  There is no need to adjust the ARM logic to reject the
use of this new flag.

No functional change yet.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-10-06 12:28:37 +01:00
Juergen Gross 41aea82de2 tools/libxl: move libxenlight to tools/libs/light
Carve out all libxenlight related sources and move them to
tools/libs/light in order to use the generic library build environment.

The closely related sources for libxl-save-helper and the libxl test
environment are being moved, too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-10-01 13:26:09 +02:00
Edwin Török ba02a2cd1c tools/ocaml/libs/xc: Fix ambiguous documentation comment
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-08-18 17:34:50 +01:00
Edwin Török a6ed77f1e0 oxenstored: fix ABI breakage introduced in Xen 4.9.0
dbc84d2983 (Xen >= 4.9.0) deleted XS_RESTRICT
from oxenstored, which caused all the following opcodes to be shifted by 1:
reset_watches became off-by-one compared to the C version of xenstored.

Looking at the C code the opcode for reset watches needs:
XS_RESET_WATCHES = XS_SET_TARGET + 2

So add the placeholder `Invalid` in the OCaml<->C mapping list.
(Note that the code here doesn't simply convert the OCaml constructor to
 an integer, so we don't need to introduce a dummy constructor).

Igor says that with a suitably patched xenopsd to enable watch reset,
we now see `reset watches` during kdump of a guest in xenstored-access.log.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Tested-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-07-21 12:31:45 +00:00
Julien Grall 59b087e395 tools/ocaml: Fix stubs build when OCaml has been compiled with -safe-string
The OCaml code has been fixed to handle properly -safe-string in Xen
4.11, however the stubs part were missed.

On OCaml newer than 4.06.1, String_Val() will return a const char *
when using -safe-string leading to build failure when this is used
in place where char * is expected.

The main use in Xen code base is when a new string is allocated. The
suggested approach by the OCaml community [1] is to use the helper
caml_alloc_initialized_string() but it was introduced by OCaml 4.06.1.

The next best approach is to cast String_val() to (char *) as the helper
would have done. So use it when we need to update the new string using
memcpy().

Take the opportunity to remove the unnecessary cast of the source as
mempcy() is expecting a void *.

[1] https://github.com/ocaml/ocaml/pull/1274

Reported-by: Dario Faggioli <dfaggioli@suse.com>
Signed-off-by: Julien Grall <jgrall@amazon.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-04-20 15:03:13 +01:00
Julien Grall 78686437e9 tools/ocaml: libxb: Avoid to use String_val() when value is bytes
Commit ec7d54dd1a "ocaml/libs/xb: Use bytes in place of strings for
mutable buffers" switch mutable buffers from string to bytes. However
the C code were still using String_Val() to access them.

While the underlying structure is the same between string and bytes, a
string is meant to be immutable. OCaml 4.06.1 and later will enforce it.
Therefore, it will not be possible to build the OCaml libs when using
-safe-string. This is because String_val() will return a const value.

To avoid plain cast in the code, the code is now switched to use
Bytes_val(). As the macro is not defined in older OCaml version, we need
to provide a stub.

Take the opportunity to switch to const the buffer in
ml_interface_write() as it should not be modified.

Reported-by: Dario Faggioli <dfaggioli@suse.com>
Signed-off-by: Julien Grall <jgrall@amazon.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-04-20 15:03:07 +01:00
Julien Grall d92ba1aa7c tools/ocaml: libxb: Harden stub_header_of_string()
stub_header_of_string() should not modify the header. So mark the
variable 'hdr' as const.

Signed-off-by: Julien Grall <jgrall@amazon.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-04-20 15:03:03 +01:00
Julien Grall 3bf69699ca tools/ocaml: libxc: Check error return in stub_xc_vcpu_context_get()
xc_vcpu_getcontext() may fail to retrieve the vcpu context. Rather than
ignoring the return value, check it and throw an error if needed.

Signed-off-by: Julien Grall <jgrall@amazon.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-04-20 15:02:17 +01:00
Andrew Cooper 270ff9a835 tools/ocaml: Drop cpuid helpers
These have no callers, and the underlying infrastructure is about to be
rewritten completely.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
2020-02-10 13:09:54 +00:00
Petre Pircalabu 368375d736 tools/ocaml: Fix build error with Arch Linux
gcc (GCC) 9.2.0 complains:

xentoollog_stubs.c: In function ‘stub_xtl_ocaml_vmessage’:
xentoollog_stubs.c:93:16: error: initialization discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
   93 |  value *func = caml_named_value(xtl->vmessage_cb) ;
      |                ^~~~~~~~~~~~~~~~

This patch constifies the pointer returned by caml_named_value in order
to the accommodate newer versions of OCaml.
In OCaml >= 4.09 the return value pointer of caml_named_value is
declared const.

https://github.com/ocaml/ocaml/commit/4f03a1467d29cf587df5a191830f1525506ee0e3

Signed-off-by: Petre Pircalabu <ppircalabu@bitdefender.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
[ wei: remove spaces before semicolons ]
Signed-off-by: Wei Liu <wl@xen.org>
2019-10-29 12:54:10 +00:00
Roger Pau Monne b183e180bc libxl: wait for the ack when issuing power control requests
Currently only suspend power control requests wait for an ack from the
domain, while power off or reboot requests simply write the command to
xenstore and exit.

Introduce a 1 minute wait for the domain to acknowledge the request, or
else return an error. The suspend code is slightly modified to use the
new infrastructure added, but shouldn't have any functional change.

Fix the ocaml bindings and also provide a backwards compatible
interface for the reboot and poweroff libxl API functions.

Reported-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
[ wei: change ret to rc to fix build ]
Signed-off-by: Wei Liu <wl@xen.org>
2019-10-02 14:43:19 +01:00
Paul Durrant babde47a3f introduce a 'passthrough' configuration option to xl.cfg...
...and hence the ability to disable IOMMU mappings, and control EPT
sharing.

This patch introduces a new 'libxl_passthrough' enumeration into
libxl_domain_create_info. The value will be set by xl either when it parses
a new 'passthrough' option in xl.cfg, or implicitly if there is passthrough
hardware specified for the domain.

If the value of the passthrough configuration option is 'disabled' then
the XEN_DOMCTL_CDF_iommu flag will be clear in the xen_domctl_createdomain
flags, thus allowing the toolstack to control whether the domain gets
IOMMU mappings or not (where previously they were globally set).

If the value of the passthrough configuration option is 'sync_pt' then
a new 'iommu_opts' field in xen_domctl_createdomain will be set with the
value XEN_DOMCTL_IOMMU_no_sharept. This will override the global default
set in iommu_hap_pt_share, thus allowing the toolstack to control whether
EPT sharing is used for the domain.

If the value of passthrough is 'enabled' then xl will choose an appropriate
default according to the type of domain and hardware support.

NOTE: The 'iommu_memkb' overhead in libxl_domain_build_info will now only
      be set if passthrough is 'sync_pt' (or xl has chosen this mode as
      a default).

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2019-09-25 16:14:55 +02:00