XEN HYPERVISOR INTERFACE
M: Boris Ostrovsky <boris.ostrovsky@oracle.com>
M: Juergen Gross <jgross@suse.com>
+R: Stefano Stabellini <sstabellini@kernel.org>
L: xen-devel@lists.xenproject.org (moderated for non-subscribers)
T: git git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git
S: Supported
{
int r;
+ /* PVH guests don't have emulated devices. */
+ if (xen_pvh_domain())
+ return;
+
/* user explicitly requested no unplug */
if (xen_emul_unplug & XEN_UNPLUG_NEVER)
return;
*/
static void xen_qlock_wait(u8 *byte, u8 val)
{
+ unsigned long flags;
int irq = __this_cpu_read(lock_kicker_irq);
/* If kicker interrupts not initialized yet, just spin */
- if (irq == -1)
+ if (irq == -1 || in_nmi())
return;
- /* clear pending */
- xen_clear_irq_pending(irq);
- barrier();
-
- /*
- * We check the byte value after clearing pending IRQ to make sure
- * that we won't miss a wakeup event because of the clearing.
- *
- * The sync_clear_bit() call in xen_clear_irq_pending() is atomic.
- * So it is effectively a memory barrier for x86.
- */
- if (READ_ONCE(*byte) != val)
- return;
+ /* Guard against reentry. */
+ local_irq_save(flags);
- /*
- * If an interrupt happens here, it will leave the wakeup irq
- * pending, which will cause xen_poll_irq() to return
- * immediately.
- */
+ /* If irq pending already clear it. */
+ if (xen_test_irq_pending(irq)) {
+ xen_clear_irq_pending(irq);
+ } else if (READ_ONCE(*byte) == val) {
+ /* Block until irq becomes pending (or a spurious wakeup) */
+ xen_poll_irq(irq);
+ }
- /* Block until irq becomes pending (or perhaps a spurious wakeup) */
- xen_poll_irq(irq);
+ local_irq_restore(flags);
}
static irqreturn_t dummy_handler(int irq, void *dev_id)
.fill 48, 1, 0
early_stack:
- .fill 256, 1, 0
+ .fill BOOT_STACK_SIZE, 1, 0
early_stack_end:
ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY,
config XEN_SELFBALLOONING
bool "Dynamically self-balloon kernel memory to target"
depends on XEN && XEN_BALLOON && CLEANCACHE && SWAP && XEN_TMEM
- default n
help
Self-ballooning dynamically balloons available kernel memory driven
by the current usage of anonymous memory ("committed AS") and
config XEN_BALLOON_MEMORY_HOTPLUG
bool "Memory hotplug support for Xen balloon driver"
- default n
depends on XEN_BALLOON && MEMORY_HOTPLUG
help
Memory hotplug support for Xen balloon driver allows expanding memory
help
Scrub pages before returning them to the system for reuse by
other domains. This makes sure that any confidential data
- is not accidentally visible to other domains. Is it more
+ is not accidentally visible to other domains. It is more
secure, but slightly less efficient. This can be controlled with
xen_scrub_pages=0 parameter and
/sys/devices/system/xen_memory/xen_memory0/scrub_pages.
config XEN_BACKEND
bool "Backend driver support"
- depends on XEN_DOM0
- default y
+ default XEN_DOM0
help
Support for backend device drivers that provide I/O services
to other virtual machines.
config XEN_PVCALLS_FRONTEND
tristate "XEN PV Calls frontend driver"
depends on INET && XEN
- default n
select XEN_XENBUS_FRONTEND
help
Experimental frontend for the Xen PV Calls protocol
config XEN_PVCALLS_BACKEND
bool "XEN PV Calls backend driver"
depends on INET && XEN && XEN_BACKEND
- default n
help
Experimental backend for the Xen PV Calls protocol
(https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
config XEN_STUB
bool "Xen stub drivers"
depends on XEN && X86_64 && BROKEN
- default n
help
Allow kernel to install stub drivers, to reserve space for Xen drivers,
i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
config XEN_ACPI_HOTPLUG_MEMORY
tristate "Xen ACPI memory hotplug"
depends on XEN_DOM0 && XEN_STUB && ACPI
- default n
help
This is Xen ACPI memory hotplug.
tristate "Xen ACPI cpu hotplug"
depends on XEN_DOM0 && XEN_STUB && ACPI
select ACPI_CONTAINER
- default n
help
Xen ACPI cpu enumerating and hotplugging
config XEN_MCE_LOG
bool "Xen platform mcelog"
depends on XEN_DOM0 && X86_64 && X86_MCE
- default n
help
Allow kernel fetching MCE error from Xen platform and
converting it into Linux mcelog format for mcelog tools
if (!watch_fired) {
watch_fired = true;
- err = xenbus_scanf(XBT_NIL, "memory", "static-max", "%llu",
- &static_max);
- if (err != 1)
- static_max = new_target;
- else
+
+ if ((xenbus_scanf(XBT_NIL, "memory", "static-max",
+ "%llu", &static_max) == 1) ||
+ (xenbus_scanf(XBT_NIL, "memory", "memory_static_max",
+ "%llu", &static_max) == 1))
static_max >>= PAGE_SHIFT - 10;
+ else
+ static_max = new_target;
+
target_diff = (xen_pv_domain() || xen_initial_domain()) ? 0
: static_max - balloon_stats.target_pages;
}
dev_err(&dev->dev, "%s\n", printf_buffer);
path_buffer = kasprintf(GFP_KERNEL, "error/%s", dev->nodename);
- if (!path_buffer ||
- xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer))
- dev_err(&dev->dev, "failed to write error node for %s (%s)\n",
- dev->nodename, printf_buffer);
+ if (path_buffer)
+ xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer);
kfree(printf_buffer);
kfree(path_buffer);