linux-stable.git/drivers/xen/Makefile, branch linux-3.18.y

x86/xen: allow privcmd hypercalls to be preempted

2015-07-21T01:12:45+00:00

[ Upstream commit db0e2aa47f0a45fc56592c25ad370f8836cbb128 ]

Hypercalls submitted by user space tools via the privcmd driver can
take a long time (potentially many 10s of seconds) if the hypercall
has many sub-operations.

A fully preemptible kernel may deschedule such as task in any upcall
called from a hypercall continuation.

However, in a kernel with voluntary or no preemption, hypercall
continuations in Xen allow event handlers to be run but the task
issuing the hypercall will not be descheduled until the hypercall is
complete and the ioctl returns to user space.  These long running
tasks may also trigger the kernel's soft lockup detection.

Add xen_preemptible_hcall_begin() and xen_preemptible_hcall_end() to
bracket hypercalls that may be preempted.  Use these in the privcmd
driver.

When returning from an upcall, call xen_maybe_preempt_hcall() which
adds a schedule point if if the current task was within a preemptible
hypercall.

Since _cond_resched() can move the task to a different CPU, clear and
set xen_in_preemptible_hcall around the call.

Signed-off-by: David Vrabel 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Sasha Levin

xen-scsiback: Add Xen PV SCSI backend driver

2014-09-23T13:36:19+00:00

Introduces the Xen pvSCSI backend. With pvSCSI it is possible for a
Xen domU to issue SCSI commands to a SCSI LUN assigned to that
domU. The SCSI commands are passed to the pvSCSI backend in a driver
domain (usually Dom0) which is owner of the physical device. This
allows e.g. to use SCSI tape drives in a Xen domU.

The code is taken from the pvSCSI implementation in Xen done by
Fujitsu based on Linux kernel 2.6.18.

Changes from the original version are:
- port to upstream kernel
- put all code in just one source file
- adapt to Linux style guide
- use target core infrastructure instead doing pure pass-through
- enable module unloading
- support SG-list in grant page(s)
- support task abort
- remove redundant struct backend
- allocate resources dynamically
- correct minor error in scsiback_fast_flush_area
- free allocated resources in case of error during I/O preparation
- remove CDB emulation, now handled by target core infrastructure

Signed-off-by: Juergen Gross 
Reviewed-by: Nicholas Bellinger 
Signed-off-by: David Vrabel

xen: Put EFI machinery in place

2014-07-18T20:23:58+00:00

This patch enables EFI usage under Xen dom0. Standard EFI Linux
Kernel infrastructure cannot be used because it requires direct
access to EFI data and code. However, in dom0 case it is not possible
because above mentioned EFI stuff is fully owned and controlled
by Xen hypervisor. In this case all calls from dom0 to EFI must
be requested via special hypercall which in turn executes relevant
EFI code in behalf of dom0.

When dom0 kernel boots it checks for EFI availability on a machine.
If it is detected then artificial EFI system table is filled.
Native EFI callas are replaced by functions which mimics them
by calling relevant hypercall. Later pointer to EFI system table
is passed to standard EFI machinery and it continues EFI subsystem
initialization taking into account that there is no direct access
to EFI boot services, runtime, tables, structures, etc. After that
system runs as usual.

This patch is based on Jan Beulich and Tang Liang work.

Signed-off-by: Jan Beulich 
Signed-off-by: Tang Liang 
Signed-off-by: Daniel Kiper 
Reviewed-by: David Vrabel 
Acked-by: Stefano Stabellini

ia64/xen: Remove Xen support for ia64 even more

2014-02-11T15:12:37+00:00

Commit d52eefb47d4e ("ia64/xen: Remove Xen support for ia64") removed
the Kconfig symbol XEN_XENCOMM. But it didn't remove the code depending
on that symbol. Remove that code now.

Signed-off-by: Paul Bolle 
Acked-by: David Vrabel 
Signed-off-by: Konrad Rzeszutek Wilk

xen/events: move drivers/xen/events.c into drivers/xen/events/

2014-01-06T15:07:38+00:00

events.c will be split into multiple files so move it into its own
directory.

Signed-off-by: David Vrabel 
Reviewed-by: Konrad Rzeszutek Wilk 
Reviewed-by: Boris Ostrovsky

xen/arm: enable PV control for ARM

2013-07-29T13:35:11+00:00

Enable lifecyle management (reboot, shutdown...) from the toolstack
for ARM guests.

Signed-off-by: Julien Grall 
Signed-off-by: Konrad Rzeszutek Wilk 
Acked-by: Stefano Stabellini

xen/arm64: Don't compile cpu hotplug

2013-07-29T13:33:15+00:00

On ARM64, when CONFIG_XEN=y, the compilation will fail because CPU hotplug is
not yet supported with XEN. For now, disable it.

Signed-off-by: Julien Grall 
Signed-off-by: Konrad Rzeszutek Wilk 
Acked-by: Mark Rutland

xen/acpi: ACPI cpu hotplug

2013-02-20T03:02:29+00:00

This patch implement real Xen ACPI cpu hotplug driver as module.
When loaded, it replaces Xen stub driver.

For booting existed cpus, the driver enumerates them.
For hotadded cpus, which added at runtime and notify OS via
device or container event, the driver is invoked to add them,
parsing cpu information, hypercalling to Xen hypervisor to add
them, and finally setting up new /sys interface for them.

Signed-off-by: Liu Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk

xen/acpi: ACPI memory hotplug

2013-02-20T03:02:26+00:00

This patch implements real Xen acpi memory hotplug driver as module.
When loaded, it replaces Xen stub driver.

When an acpi memory device hotadd event occurs, it notifies OS and
invokes notification callback, adding related memory device and parsing
memory information, finally hypercall to xen hypervisor to add memory.

Signed-off-by: Liu Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk

xen/stub: driver for memory hotplug

2013-02-20T03:02:25+00:00

This patch create a file (xen-stub.c) for Xen stub drivers.
Xen stub drivers are used to reserve space for Xen drivers, i.e.
memory hotplug and cpu hotplug, and to block native drivers loaded,
so that real Xen drivers can be modular and loaded on demand.

This patch is specific for Xen memory hotplug (other Xen logic
can add stub drivers on their own). The xen stub driver will
occupied earlier via subsys_initcall (than native memory hotplug
driver via module_init and so blocking native). Later real Xen
memory hotplug logic will unregister the stub driver and register
itself to take effect on demand.

Signed-off-by: Liu Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk