The use of seabios defconfig kills boot performance of Windows guests
because the default is for the int13 handler to use PIO when accessing
the emulated IDE device.
By instead using a canned configuration with the ATA settings overridden
to enable DMA access (and also wider PIO) boot performance is markedly
improved without the need to use a different (and possibly not supported)
device model.
This patch adds the canned configuration into tools/firmware and modifies
the Makefile rule to copy it into place.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
colo_merge_secondary_dirty_bitmap() unconditionally free()s the .data
member of its local xc_sr_record structure rec on its exit path.
However, if the initial call to read_record() fails then this member is
uninitialised. Initialise it.
Signed-off-by: Joshua Otto <jtotto@uwaterloo.ca>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Add functions to libxl to setup a Xen 9pfs frontend/backend connection.
Add support to xl to parse a 9pfs option in the VM config file, in the
following format:
p9=["tag=share_dir,security_model=none,path=/root/share_dir"]
where tag identifies the 9pfs share and it is required to mount it on
the guest side, path is the path of the filesystem to share and the only
security_model supported is "none" which means that files are stored
using the same credentials as they are created on the guest (no user
ownership squash or remap).
Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
vlddqu is encoded with 0xf2 which causes it to fall into the Scalar general
case in x86_decode_twobyte(). However, it really does have just two operands,
so must remain TwoOp
AFL discovered that the instruction c5 5b f0 3c e5 95 0a cd 63 was considered
valid despite it being a two operand instruction and VEX.vvvv having the value
11. The resulting use in a stub yielded #UD.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
For information related to transaction conflicts, potentially frequent
logging at "info" priority has been changed to "debug" priority, and
once per two minutes there is an "info" priority summary.
Additional detailed logging has been added at "debug" priority.
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
In the main loop, when choosing the timeout for the select function
call, we were setting it so as to wake up to issue conflict-credit to
any domains that could accept it. When xenstore is idle, this would
mean waking up every 50ms (by default) to do no work. With this
commit, we check whether any domain is below its cap, and if not then
we set the timeout for longer (the same timeout as before the
conflict-protection feature was added).
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Reviewed-by: Jonathan Davies <jonathan.davies@citrix.com>
The packet telling us to end the transaction has always carried an
argument telling us whether to commit.
If the transaction made no modifications to the tree, now we ignore
that argument and do not commit: it is just a waste of effort.
This makes read-only transactions immune to conflicts, and means that
we do not need to store any of their details in the history that is
used for assigning blame for conflicts.
We count a transaction as a read-only transaction only if it contains
no operations that modified the tree.
This means that (for example) a transaction that creates a new node
then deletes it would NOT count as read-only, even though it makes no
change overall. A more sophisticated algorithm could judge the
transaction based on comparison of its initial and final states, but
this would add complexity and computational cost.
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Reviewed-by: Jonathan Davies <jonathan.davies@citrix.com>
We already avoid inter-domain conflicts but now allow intra-domain
conflicts. Although there are no known practical examples of a domain
that might perform operations that conflict with its own transactions,
this is conceivable, so here we avoid changing those semantics
unnecessarily.
When a transaction commit fails with a conflict and we look through
the history of commits to see which connection(s) to blame, ignore
historical commits that were made by the same connection as the
failing commit.
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Reviewed-by: Jonathan Davies <jonathan.davies@citrix.com>
Blame each connection found to have made a commit that would cause this
transaction to fail. Each blamed connection is penalised by having its
conflict-credit decremented.
Note the change in semantics for the replay function: we no longer stop after
finding the first operation that can't be replayed. This allows us to identify
all operations that conflicted with this transaction, not just the one that
conflicted first.
Signed-off-by: Jonathan Davies <jonathan.davies@citrix.com>
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
v1 Reviewed-by: Christian Lindig <christian.lindig@citrix.com>
Changes since v1:
* use correct log levels for informational messages
Changes since v2:
* fix the blame algorithm and improve logging
(fix was reviewed by Jonathan Davies)
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Since the list of historic activity cannot grow without bound, it is safe to use
this to track commits.
Signed-off-by: Jonathan Davies <jonathan.davies@citrix.com>
Reviewed-by: Thomas Sanders <thomas.sanders@citrix.com>
The history of commits is to be used for working out which historical
commit(s) (including atomic writes) caused conflicts with a
currently-failing commit of a transaction. Any commit that was made
before the current transaction started cannot be relevant. Therefore
we never need to keep history from before the start of the
longest-running transaction that is open at any given time: whenever a
transaction ends (with or without a commit) then if it was the
longest-running open transaction we can delete history up until start
of the the next-longest-running open transaction.
Some transactions might stay open for a very long time, so if any
transaction exceeds conflict_max_history_seconds then we remove it
from consideration in this context, and will not guarantee to keep
remembering about historical commits made during such a transaction.
We implement this by keeping a list of all open transactions that have
not been open too long. When a transaction ends, we remove it from the
list, along with any that have been open longer than the maximum; then
we delete any history from before the start of the longest-running
transaction remaining in the list.
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Reviewed-by: Jonathan Davies <jonathan.davies@citrix.com>
Reviewed-by: Christian Lindig <christian.lindig@citrix.com>
There is no need to record "read" operations as they will never cause another
transaction to fail.
Signed-off-by: Jonathan Davies <jonathan.davies@citrix.com>
Reviewed-by: Thomas Sanders <thomas.sanders@citrix.com>
Forward port to xen-unstable:
* Remove Xenbus.Xb.Op.Restrict
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Add ability to track xenstore tree operations -- either non-transactional
operations or committed transactions.
For now, the call to actually retain commits is commented out because history
can grow without bound.
For now, we call record_commit for all non-transactional operations. A
subsequent patch will make it retain only the ones with side-effects.
Signed-off-by: Jonathan Davies <jonathan.davies@citrix.com>
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Reviewed-by: Christian Lindig <christian.lindig@citrix.com>
When processing connections, skip those from domains with no remaining
conflict-credit.
Also, issue a point of conflict-credit at regular intervals, the
period being set by the configuration option "conflict-max-history-
seconds". When issuing conflict-credit, we give a point either to
every domain at once (one each) or only to the single domain at the
front of the queue, depending on the configuration option
"conflict-rate-limit-is-aggregate".
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Reviewed-by: Jonathan Davies <jonathan.davies@citrix.com>
Reviewed-by: Christian Lindig <christian.lindig@citrix.com>
This commit gives each domain a conflict-credit variable, which will
later be used for limiting how often a domain can cause other domain's
transaction-commits to fail.
This commit also provides functions and data for manipulating domains
and their conflict-credit, and checking whether they have credit.
Signed-off-by: Thomas Sanders <thomas.sanders@citrix.com>
Reviewed-by: Jonathan Davies <jonathan.davies@citrix.com>
Reviewed-by: Christian Lindig <christian.lindig@citrix.com>
This avoids a rogue client being about to stall another client (eg the
toolstack) indefinitely.
This is XSA-206.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Classic PV shadow paging Dom0 has been broken for years, and can't
possibly be configured after 4045953.
PVH shadow paging Dom0 should still be possible.
Change the code and documentation to clarify that.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper@citrix.com>
Within context_saved(), we call the context_saved hook,
and we use VCPU2OP() to determine from what scheduler.
VCPU2OP uses DOM2OP, which uses d->cpupool, which is
NULL when d is the idle domain. And in that case,
DOM2OP just returns ops, the scheduler of cpupool0.
Therefore, if:
- cpupool0's scheduler defines context_saved (like
Credit2 and RTDS do),
- we are not in cpupool0 (i.e., our scheduler is
not ops),
- we are context switching from idle,
we call VCPU2OP(idle_vcpu), which means
DOM2OP(idle->cpupool), which is ops.
Therefore, we both:
- check if context_saved is defined in the wrong
scheduler;
- if yes, call the wrong one.
When using Credit2 at boot, and also Credit2 in
the other cpupool, this is wrong but innocuous,
because it only involves the idle vcpus.
When using Credit2 at boot, and Credit1 in the
other cpupool, this is *totally* wrong, and
it's by chance it does not explode!
When using Credit2 and other schedulers I'm
developping, I hit the following assert (in
sched_credit2.c, on a CPU inside a cpupool that
does not use Credit2):
csched2_context_saved()
{
...
ASSERT(!vcpu_on_runq(svc));
...
}
Fix this by dealing explicitly, in VCPU2OP, with
idle vcpus, returning the scheduler of the pCPU
they (always) run on.
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Commit 5823d6eb "add a call to restrict the handle" added a new function
to the foreignmemory API. This API is considered stable and so the new
function should be bound to a new version.
This patch creates version 1.1 of the API, dependent on version 1.0, and
binds the restrict call to version 1.1. Thus version 1.0 is as it was
before the new function was added.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
* Drop trailing whitespace
* Consistently apply Xen style
* Introduce a local variable block
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
The boolean pse2M is misnamed, because it might refer to a 4M superpage.
Switch the logic to be in terms of the level of the leaf entry, and rearrange
the calls to set_ad_bits() to be a fallthrough switch statement, to make it
easier to follow.
Alter set_ad_bits() to take properly typed pointers and booleans rather than
integers.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
The shadow logic should not create a valid/present shadow of a guest PTE which
contains reserved bits from the guests point of view. It is not guaranteed
that the hardware pagewalk will come to the same conclusion, and raise a
pagefault.
Shadows created on demand from the pagefault handler are fine because the
pagewalk over the guest tables will have injected the fault into the guest
rather than creating a shadow.
However, shadows created by sh_resync_l1() and sh_prefetch() haven't undergone
a pagewalk and need to account for reserved bits before creating the shadow.
In practice, this means a 3-level guest could previously cause PTEs with bits
63:52 set to be shadowed (and discarded). This PTE should cause #PF[RSVD]
when encountered by hardware, but the installed shadow is valid and hardware
doesn't fault.
Reuse the pagewalk reserved bits helpers, and assert in
l?e_propagate_from_guest() that shadows are not attempted to be created with
reserved bits set.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Tim Deegan <tim@xen.org>
The existing pagetable walker has complicated return semantics, which squeeze
multiple pieces of information into single integer. This would be fine if the
information didn't overlap, but it does.
Specifically, _PAGE_INVALID_BITS for 3-level guests alias _PAGE_PAGED and
_PAGE_SHARED. A guest which constructs a PTE with bits 52 or 53 set (the
start of the upper software-available range) will create a virtual address
which, when walked by Xen, tricks Xen into believing the frame is paged or
shared. This behaviour was introduced by XSA-173 (c/s 8b17648).
It is also complicated to turn rc back into a normal pagefault error code.
Instead, change the calling semantics to return a boolean indicating success,
and have the function accumulate a real pagefault error code as it goes
(including synthetic error codes, which do not alias hardware ones). This
requires an equivalent adjustment to map_domain_gfn().
Issues fixed:
* 2-level PSE36 superpages now return the correct translation.
* 2-level L2 superpages without CR0.PSE now return the correct translation.
* SMEP now inhibits a user instruction fetch even if NX isn't active.
* Supervisor writes without CR0.WP now set the leaf dirty bit.
* L4e._PAGE_GLOBAL is strictly reserved on AMD.
* 3-level l3 entries have all reserved bits checked.
* 3-level entries can no longer alias Xen's idea of paged or shared.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Some bits are unconditionally reserved in pagetable entries, or reserved
because of alignment restrictions. Other bits are reserved because of control
register configuration.
Introduce helpers which take an individual vcpu and guest pagetable entry, and
calculates whether any reserved bits are set.
While here, add a couple of newlines to aid readability.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Switch them to returning bool, and taking const parameters.
Rename guest_supports_superpages() to guest_can_use_l2_superpages() to
indicate which level of pagetables it is actually referring to as well as
indicating that it is more complicated than just control register settings,
and rename guest_supports_1G_superpages() to guest_can_use_l3_superpages() for
consistency.
guest_can_use_l3_superpages() is a static property of the domain, rather than
control register settings, so is switched to take a domain pointer.
hvm_pse1gb_supported() is inlined into its sole user because it isn't strictly
hvm-specific (it is hap-specific) and really should be beside a comment
explaining why the cpuid policy is ignored.
guest_supports_nx() on the other hand refers simply to a control register bit,
and is renamed to guest_nx_enabled().
While cleaning up part of the file, clean up all trailing whilespace, and fix
one comment which accidently refered to PG living in CR4 rather than CR0.
Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
Use a larger e820 map buffer for non-BIOS memory map sources. This
requires to have different defines for the maximum number of E820 map
entries for the raw BIOS buffer and the later used struct e820map.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Instead of using the E820 raw buffer for BIOS, EFI and multiboot based
memory map information use it for the BIOS interface only. This will
enable us to support more E820 entries than the limited trampoline
located buffer can.
Add a new raw e820 table for common purpose and copy the BIOS buffer
to it. Doing the copying in assembly avoids the need to export the
symbols for the BIOS E820 buffer and number of entries.
Signed-off-by: Juergen Gross <jgross@suse.com>
[jb: eliminate an unneeded local variable]
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The hypervisor needs a trampoline in low memory for early boot and
later for bringing up cpus and during wakeup from suspend. Today this
trampoline is kept completely even if most of it isn't needed later.
Split the trampoline into a permanent part and a temporary part needed
at early boot only. Introduce a new entry at the boundary.
Reduce the stack for wakeup code in order for the permanent
trampoline to fit in a single page. 4k of stack seems excessive, about
3k should be more than enough.
Add an ASSERT() to the linker script to ensure the wakeup stack is
always at least 3k.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
PVH (both v1 and v2) guest is actually an translated guest. It should be
able to manipulate page table for other domains when acting as Dom0.
The removal of PVHv1 deleted the special case for PVH guest but didn't
add a check for HVM guest.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Recent discussions on xen-devel have highlighted that to properly
support displacing emulated NVMe disks with PV equivalents will need
updates to PV frontends. Therefore it is important that, if an emulated
NVMe disk is exposed to a guest with an existing PV storage frontend,
that frontend does not inadvertently cause unplug of that emulated
disk when unplugging IDE or SCSI disks.
This patch defines a new bit in the mask used to instruct QEMU to unplug
emulated devices which will instruct QEMU to unplug NVMe disks and limits
the semantics of the existing 'all' disk-unplug bit to only IDE and/or SCSI
disks.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Execute the clean target for both arm and x86 architecture.
When trying to build Xen for a different architecture in the same
tree, the command make clean will only remove temporary files for
the host architecture.
This will lead a compilation error when trying to build ARM64 and
ARM32 Xen in the same tree.
(See also: https://lists.xenproject.org/archives/html/xen-devel/2016-11/msg02176.html)
Signed-off-by: Luca Miccio <lucmiccio@gmail.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Commit 8ef5f344d0 "tools/libxendevicemodel: add a call to restrict the
handle" added a function to the devicemodel interface to restrict
operations through the API to a specific domain, where a capable under-
lying privcmd driver exists.
This patch adds similar functionality to the xenforeignmemory API. This
will be necessary (as much as xendevicemodel restriction) for limiting
the scope of device models to specific domains.
NOTE: My patch to the linux kernel [1] added the appropriate checks to
the foreign memory ioctls.
[1] https://git.kernel.org/cgit/linux/kernel/git/ostr/linux.git/commit/?id=4610d240
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The code which used that field has been deleted. Found by code
inspection.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
There is only one single user of VALID_GFN(). Inline the macro to remove the
added layer of indirection in sh_gva_to_gfn()
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
... as being unused and having been unusable: It was clearly intended
for use in asm(), yet was placed inside __ASSEMBLY__ conditionals.
Also drop __ALIGN{,_STR} - there's no need to have a second flavor of
these constructs with no difference in behavior.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Section 2.4.4 of the Hypervisor Top Level Functional Specification states
that enabling bit 10 in EDX of CPUID leaf 3 advertises to Windows a set
of MSRs into which it can write crash information.
This patch advertises that bit and implements the MSRs such that Xen can
log the information if a Windows guest crashes.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
The current threshold before the guest issues the hypercall is, and always
has been, hard-coded to 2047. It is not clear where this number came
from so, to at least allow for ease of experimentation, this patch makes
the threshold tunable via the Xen command line.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The Hypervisor Top Level Functional Specification v5.0a states in section
2.5:
"The hypervisor version information is encoded in leaf 0x40000002. Two
version numbers are provided: the main version and the service version.
The main version includes a major and minor version number and a build
number. These correspond to Microsoft Windows release numbers."
It also goes on to advise clients (i.e. guest versions of Windows) to use
the following algorithm to determine compatibility with the hypervisor
enlightenments:
if <your-main-version> greater than <hypervisor-main-version>
{
your version is compatible
}
else if <your-main-version> equal to <hypervisor-main-version> and
<your-service-version> greater than or equal to <hypervisor-service-version>
{
your version is compatible
}
else
{
your version is NOT compatible
}
So, clearly putting Xen hypervisor version information in that leaf is
spurious, but we probably get away with it because Xen's major version
is lower than the major version of Windows in which Hyper-V first
appeared (Server 2008).
This patch changes the leaf to use the kernel major and minor
versions, and build number from Windows Server 2008 (64-bit) by default.
These default values can be overriden from the Xen command line using new
'viridian-version' parameter.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Replace raw xs_read() calls with libxl__xs_read_checked() and bail on error.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Paul Durrant