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Diffstat (limited to 'drivers/xen/events.c')
-rw-r--r--drivers/xen/events.c70
1 files changed, 63 insertions, 7 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index db8f506817f0..d659480125f0 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -29,6 +29,7 @@
#include <linux/bootmem.h>
#include <linux/slab.h>
+#include <asm/desc.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
#include <asm/idle.h>
@@ -36,10 +37,14 @@
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
+#include <xen/xen.h>
+#include <xen/hvm.h>
#include <xen/xen-ops.h>
#include <xen/events.h>
#include <xen/interface/xen.h>
#include <xen/interface/event_channel.h>
+#include <xen/interface/hvm/hvm_op.h>
+#include <xen/interface/hvm/params.h>
/*
* This lock protects updates to the following mapping and reference-count
@@ -617,17 +622,13 @@ static DEFINE_PER_CPU(unsigned, xed_nesting_count);
* a bitset of words which contain pending event bits. The second
* level is a bitset of pending events themselves.
*/
-void xen_evtchn_do_upcall(struct pt_regs *regs)
+static void __xen_evtchn_do_upcall(void)
{
int cpu = get_cpu();
- struct pt_regs *old_regs = set_irq_regs(regs);
struct shared_info *s = HYPERVISOR_shared_info;
struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
unsigned count;
- exit_idle();
- irq_enter();
-
do {
unsigned long pending_words;
@@ -667,10 +668,26 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
} while(count != 1);
out:
+
+ put_cpu();
+}
+
+void xen_evtchn_do_upcall(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+
+ exit_idle();
+ irq_enter();
+
+ __xen_evtchn_do_upcall();
+
irq_exit();
set_irq_regs(old_regs);
+}
- put_cpu();
+void xen_hvm_evtchn_do_upcall(void)
+{
+ __xen_evtchn_do_upcall();
}
/* Rebind a new event channel to an existing irq. */
@@ -933,6 +950,40 @@ static struct irq_chip xen_dynamic_chip __read_mostly = {
.retrigger = retrigger_dynirq,
};
+int xen_set_callback_via(uint64_t via)
+{
+ struct xen_hvm_param a;
+ a.domid = DOMID_SELF;
+ a.index = HVM_PARAM_CALLBACK_IRQ;
+ a.value = via;
+ return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
+}
+EXPORT_SYMBOL_GPL(xen_set_callback_via);
+
+/* Vector callbacks are better than PCI interrupts to receive event
+ * channel notifications because we can receive vector callbacks on any
+ * vcpu and we don't need PCI support or APIC interactions. */
+void xen_callback_vector(void)
+{
+ int rc;
+ uint64_t callback_via;
+ if (xen_have_vector_callback) {
+ callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
+ rc = xen_set_callback_via(callback_via);
+ if (rc) {
+ printk(KERN_ERR "Request for Xen HVM callback vector"
+ " failed.\n");
+ xen_have_vector_callback = 0;
+ return;
+ }
+ printk(KERN_INFO "Xen HVM callback vector for event delivery is "
+ "enabled\n");
+ /* in the restore case the vector has already been allocated */
+ if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
+ alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
+ }
+}
+
void __init xen_init_IRQ(void)
{
int i;
@@ -947,5 +998,10 @@ void __init xen_init_IRQ(void)
for (i = 0; i < NR_EVENT_CHANNELS; i++)
mask_evtchn(i);
- irq_ctx_init(smp_processor_id());
+ if (xen_hvm_domain()) {
+ xen_callback_vector();
+ native_init_IRQ();
+ } else {
+ irq_ctx_init(smp_processor_id());
+ }
}