libxl__wait_for_device_model blocks, with the ctx lock held, waiting
for a response from the device model. If the dm doesn't respond
quickly (for example, because it has crashed), this may block the
whole process. Explain this in a comment, rename the function to
libxl__wait_for_device_model_deprecated, and explain what to use
instead.
libxl__wait_for_offspring is the core implementation for the above.
Its name leads people to think it might be generally useful for
waiting for children, which is far from the case. It only waits for
xenstore. Also it has the problems described above. Explain this,
rename it to libxl__xenstore_child_wait_deprecated, and explain what
to use instead.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
libxl__datacopier_prefixdata would prepend a deliberately short block
(not just a half-full one, but one with a short buffer) to the
dc->bufs queue. However, this is wrong because datacopier_readable
will find it and try to continue to fill it up.
Instead, allocate a full-sized buffer.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Tested-by: Chunyan Liu <cyliu@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The original patch for
c/s 67a3542c5b
"common/vsprintf: Refactor string() out of vsnprintf()"
specifically used signed integers, identical to the code copied out of vsprintf.
When committed, these had changed to unsigned integers, which causes a
functional change. This causes glacial boot performance and an excessive
quantity of spaces printed to the serial console, as we loop to the upper
bound of a 32bit integer.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Without this, code interrupted by SIGCHLD may experience strange
values of errno. (As far as I know this is not the cause of any
reported bugs.)
This fix should be backported in due course.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
... as being generally insufficient: Either has_arch_pdevs() or
cache_flush_permitted() should be used (in particular, it is
insufficient to consider MMIO ranges alone - I/O port ranges have the
same requirements if available to a guest).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
A malicious or buggy guest can cause another domain to spin
indefinitely by repeatedly writing to an event word when the other
guest is trying to link a new event. The cmpxchg() in
evtchn_fifo_set_link() will repeatedly fail and the loop may never
terminate.
Fixing this requires a change to the ABI which is documented in draft
H of the design.
http://xenbits.xen.org/people/dvrabel/event-channels-H.pdf
Since a well-behaved guest only makes a limited set of state changes,
the loop can terminate early if the guest makes an invalid state
transition.
The guest may:
- clear LINKED and LINK.
- clear PENDING
- set MASKED
- clear MASKED
It is valid for the guest to mask and unmask an event at any time so
specify that it is not valid for a guest to clear MASKED if Xen is
trying to update LINK. Indicate this to the guest with an additional
BUSY bit in the event word. The guest must not clear MASKED if BUSY
is set and it should spin until BUSY is cleared.
The remaining valid writes (clear LINKED, clear PENDING, set MASKED,
clear MASKED by Xen) will limit the number of failures of the
cmpxchg() to at most 4. A clear of LINKED will also terminate the
loop early. Therefore, the loop can then be limited to at most 4
iterations.
If the buggy or malicious guest does cause the loop to exit with
LINKED set and LINK unset then that buggy guest will lose events.
Reported-by: Anthony Liguori <aliguori@amazon.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
There's a window during scheduling where "current" and the active VMCS
may disagree: The former gets set much earlier than the latter. Since
both vmx_vmcs_enter() and vmx_vmcs_exit() immediately return when the
subject vCPU is "current", accessing VMCS fields would, depending on
whether there is any currently active VMCS, either read wrong data, or
cause a crash.
Going forward we might want to consider reducing the window during
which vmx_vmcs_enter() might fail (e.g. doing a plain __vmptrld() when
v->arch.hvm_vmx.vmcs != this_cpu(current_vmcs) but arch_vmx->active_cpu
== -1), but that would add complexities (acquiring and - more
importantly - properly dropping v->arch.hvm_vmx.vmcs_lock) that don't
look worthwhile adding right now.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
For one, nestedsvm_vmcb_map() error checking must not consist of using
assertions: Global (permanent) mappings can fail, and hence failure
needs to be dealt with properly. And non-global (transient) mappings
can't fail anyway.
And then the I/O port access bitmap handling was broken: It checked
only to first of the accessed ports rather than each of them.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Christoph Egger <chegger@amazon.de>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
In the existing kexec hypercall, the load and unload ops depend on
internals of the Linux kernel (the page list and code page provided by
the kernel). The code page is used to transition between Xen context
and the image so using kernel code doesn't make sense and will not
work for PVH guests.
Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops
that no longer require a code page to be provided by the guest -- Xen
now provides the code for calling the image directly.
The new load op looks similar to the Linux kexec_load system call and
allows the guest to provide the image data to be loaded. The guest
specifies the architecture of the image which may be a 32-bit subarch
of the hypervisor's architecture (i.e., an EM_386 image on an
EM_X86_64 hypervisor).
The toolstack can now load images without kernel involvement. This is
required for supporting kexec when using a dom0 with an upstream
kernel.
Crash images are copied directly into the crash region on load.
Default images are copied into domheap pages and a list of source and
destination machine addresses is created. This is list is used in
kexec_reloc() to relocate the image to its destination.
The old load and unload sub-ops are still available (as
KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top
of the new infrastructure.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Don Slutz <dslutz@verizon.com>
Tested-by: Don Slutz <dslutz@verizon.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Daniel Kiper <daniel.kiper@oracle.com>
Acked-by: Keir Fraser <keir@xen.org>
Add replacement KEXEC_CMD_load and KEXEC_CMD_unload sub-ops to the
kexec hypercall. These new sub-ops allow a priviledged guest to
provide the image data to be loaded into Xen memory or the crash
region instead of guests loading the image data themselves and
providing the relocation code and metadata.
The old interface is provided to guests requesting an interface
version prior to 4.4.
Bump __XEN_LATEST_INTERFACE_VERSION__ to 0x00040400.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Don Slutz <dslutz@verizon.com>
Tested-by: Don Slutz <dslutz@verizon.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Daniel Kiper <daniel.kiper@oracle.com>
Acked-by: Keir Fraser <keir@xen.org>
Also adjust the one common user of print_symbol() to use the new printk()
format. While adjusting the format string, increase the width so a
long-to-expire plt_overflow() timer doesn't break the column alignment.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Introduce the %ps and %pS format options for printing a symbol.
%ps will print the symbol name and optional offset and size
%pS will print the symbol name and unconditional offset and size
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
If the domain's NUMA node-affinity is being specified by the
user/toolstack (instead of being automatically computed by Xen),
we really should stick to that. This means domain_update_node_affinity()
is wrong when it filters out some stuff from there even in "!auto"
mode.
This commit fixes that. Of course, this does not mean node-affinity
is always honoured (e.g., a vcpu won't run on a pcpu of a different
cpupool) but the necessary logic for taking into account all the
possible situations lives in the scheduler code, where it belongs.
What could happen without this change is that, under certain
circumstances, the node-affinity of a domain may change when the
user modifies the vcpu-affinity of the domain's vcpus. This, even
if probably not a real bug, is at least something the user does
not expect, so let's avoid it.
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
When creating CPU device tree properties, copy the
clock-frequency if present.
Quiets annoying messages from linux kernel:
"/cpus/cpu@0 missing clock-frequency property"
Signed-off-by: Jon Fraser <jfraser@broadcom.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Allow a domain updating existing xenstore keys even if it has already reached
its max entries limit
As updating existing key won't increase the number of entries belonging to a
domain, we should avoid checking the max entries limit prematurely. The patch
addresses this issue in the following functions: write/add, mkdir, setperms.
Signed-off-by: Zheng Li <zheng.li@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Libxl functions such as libxl_domain_create_new take large structs
of configuration parameters. Often, we would like to use the default
values for many of these parameters.
The struct and keyed-union types in libxl have init functions, which
fill in the defaults for a given type. This commit provides an OCaml
interface to obtain records of defaults by calling the relevant init
function.
These default records can be used as a base to construct your own
records, and to selectively override parameters where needed.
For example, a Domain_create_info record can now be created as follows:
Xenlight.Domain_create_info.({ default ctx () with
ty = Xenlight.DOMAIN_TYPE_PV;
name = Some vm_name;
uuid = vm_uuid;
})
For types with KeyedUnion fields, such as Domain_build_info, a record
with defaults is obtained by specifying the type key:
Xenlight.Domain_build_info.default ctx ~ty:Xenlight.DOMAIN_TYPE_HVM ()
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The libxl IDL is based on C type "char *", and therefore "strings" can
by NULL, or be an actual string. In ocaml, it is common to encode such
things as option types.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
In order to avoid newly created OCaml values from being GC'ed, they must be
registered as roots with the GC, before an iteration of the GC may happen. The
Val_* functions potentially allocate new values on the OCaml heap, and may
trigger an iteration of the OCaml GC.
The way to register a value with the GC is to assign it to a variable declared
with a CAMLparam or CAMLlocal macro, which put the value into a struct that
can be reached from a GC root.
This leads to slightly weird looking C code, but avoids hard to find segfaults.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
This allows setting the namespace for values of an Enumeration to be different
from the namespace of the Enumeration itself.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Since the context has a logger we can get rid of the logger built into these
bindings and use the xentoollog bindings instead.
The gc is of limited use when most things are freed with libxl_FOO_dispose,
so get rid of that too.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Ian Jackson
Andrew Cooper
Jan Beulich
David Vrabel
Dario Faggioli
Stefano Stabellini
Julien Grall
Matthew Daley
Jon Fraser
Zheng Li
Rob Hoes