path: root/drivers/xen/xenbus
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-24 16:02:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-24 16:02:08 -0700
commitb5f4035adfffbcc6b478de5b8c44b618b3124aff (patch)
treee7a5f011d8aaf5c95edf933f98f25dfc8fa46837 /drivers/xen/xenbus
parentce004178be1bbaa292e9e6497939e2970300095a (diff)
parent68c2c39a76b094e9b2773e5846424ea674bf2c46 (diff)
Merge tag 'stable/for-linus-3.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen updates from Konrad Rzeszutek Wilk: "Features: * Extend the APIC ops implementation and add IRQ_WORKER vector support so that 'perf' can work properly. * Fix self-ballooning code, and balloon logic when booting as initial domain. * Move array printing code to generic debugfs * Support XenBus domains. * Lazily free grants when a domain is dead/non-existent. * In M2P code use batching calls Bug-fixes: * Fix NULL dereference in allocation failure path (hvc_xen) * Fix unbinding of IRQ_WORKER vector during vCPU hot-unplug * Fix HVM guest resume - we would leak an PIRQ value instead of reusing the existing one." Fix up add-add onflicts in arch/x86/xen/enlighten.c due to addition of apic ipi interface next to the new apic_id functions. * tag 'stable/for-linus-3.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: do not map the same GSI twice in PVHVM guests. hvc_xen: NULL dereference on allocation failure xen: Add selfballoning memory reservation tunable. xenbus: Add support for xenbus backend in stub domain xen/smp: unbind irqworkX when unplugging vCPUs. xen: enter/exit lazy_mmu_mode around m2p_override calls xen/acpi/sleep: Enable ACPI sleep via the __acpi_os_prepare_sleep xen: implement IRQ_WORK_VECTOR handler xen: implement apic ipi interface xen/setup: update VA mapping when releasing memory during setup xen/setup: Combine the two hypercall functions - since they are quite similar. xen/setup: Populate freed MFNs from non-RAM E820 entries and gaps to E820 RAM xen/setup: Only print "Freeing XXX-YYY pfn range: Z pages freed" if Z > 0 xen/gnttab: add deferred freeing logic debugfs: Add support to print u32 array in debugfs xen/p2m: An early bootup variant of set_phys_to_machine xen/p2m: Collapse early_alloc_p2m_middle redundant checks. xen/p2m: Allow alloc_p2m_middle to call reserve_brk depending on argument xen/p2m: Move code around to allow for better re-usage.
Diffstat (limited to 'drivers/xen/xenbus')
3 files changed, 58 insertions, 0 deletions
diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
index 2eff7a6aaa2..52fe7ad0766 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -234,3 +234,9 @@ int xb_init_comms(void)
return 0;
+void xb_deinit_comms(void)
+ unbind_from_irqhandler(xenbus_irq, &xb_waitq);
+ xenbus_irq = 0;
diff --git a/drivers/xen/xenbus/xenbus_comms.h b/drivers/xen/xenbus/xenbus_comms.h
index 6e42800fa49..c8abd3b8a6c 100644
--- a/drivers/xen/xenbus/xenbus_comms.h
+++ b/drivers/xen/xenbus/xenbus_comms.h
@@ -35,6 +35,7 @@
int xs_init(void);
int xb_init_comms(void);
+void xb_deinit_comms(void);
/* Low level routines. */
int xb_write(const void *data, unsigned len);
diff --git a/drivers/xen/xenbus/xenbus_dev_backend.c b/drivers/xen/xenbus/xenbus_dev_backend.c
index 3d3be78c109..be738c43104 100644
--- a/drivers/xen/xenbus/xenbus_dev_backend.c
+++ b/drivers/xen/xenbus/xenbus_dev_backend.c
@@ -8,7 +8,11 @@
#include <xen/xen.h>
#include <xen/page.h>
+#include <xen/xenbus.h>
#include <xen/xenbus_dev.h>
+#include <xen/grant_table.h>
+#include <xen/events.h>
+#include <asm/xen/hypervisor.h>
#include "xenbus_comms.h"
@@ -22,6 +26,50 @@ static int xenbus_backend_open(struct inode *inode, struct file *filp)
return nonseekable_open(inode, filp);
+static long xenbus_alloc(domid_t domid)
+ struct evtchn_alloc_unbound arg;
+ int err = -EEXIST;
+ xs_suspend();
+ /* If xenstored_ready is nonzero, that means we have already talked to
+ * xenstore and set up watches. These watches will be restored by
+ * xs_resume, but that requires communication over the port established
+ * below that is not visible to anyone until the ioctl returns.
+ *
+ * This can be resolved by splitting the ioctl into two parts
+ * (postponing the resume until xenstored is active) but this is
+ * unnecessarily complex for the intended use where xenstored is only
+ * started once - so return -EEXIST if it's already running.
+ */
+ if (xenstored_ready)
+ goto out_err;
+ gnttab_grant_foreign_access_ref(GNTTAB_RESERVED_XENSTORE, domid,
+ virt_to_mfn(xen_store_interface), 0 /* writable */);
+ arg.dom = DOMID_SELF;
+ arg.remote_dom = domid;
+ err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, &arg);
+ if (err)
+ goto out_err;
+ if (xen_store_evtchn > 0)
+ xb_deinit_comms();
+ xen_store_evtchn = arg.port;
+ xs_resume();
+ return arg.port;
+ out_err:
+ xs_suspend_cancel();
+ return err;
static long xenbus_backend_ioctl(struct file *file, unsigned int cmd, unsigned long data)
if (!capable(CAP_SYS_ADMIN))
@@ -33,6 +81,9 @@ static long xenbus_backend_ioctl(struct file *file, unsigned int cmd, unsigned l
return xen_store_evtchn;
return -ENODEV;
+ return xenbus_alloc(data);
return -ENOTTY;