[PATCH 03/12] evtchn delivery on HVM

[Stefano Stabellini]

From: Sheng Yang <sheng@xxxxxxxxxxxxxxx>

Set the callback to receive evtchns from Xen, using the
callback vector delivery mechanism.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Signed-off-by: Sheng Yang <sheng@xxxxxxxxxxxxxxx>
---
 arch/x86/xen/enlighten.c         |   35 +++++++++++++++++++++++++++++++++++
 drivers/xen/events.c             |   31 ++++++++++++++++++++++++-------
 include/xen/events.h             |    3 +++
 include/xen/hvm.h                |    9 +++++++++
 include/xen/interface/features.h |    3 +++
 5 files changed, 74 insertions(+), 7 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 87a3b10..502c4f8 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -37,8 +37,11 @@
 #include <xen/interface/vcpu.h>
 #include <xen/interface/memory.h>
 #include <xen/interface/hvm/hvm_op.h>
+#include <xen/interface/hvm/params.h>
 #include <xen/features.h>
 #include <xen/page.h>
+#include <xen/hvm.h>
+#include <xen/events.h>
 #include <xen/hvc-console.h>
 
 #include <asm/paravirt.h>
@@ -79,6 +82,8 @@ struct shared_info xen_dummy_shared_info;
 
 void *xen_initial_gdt;
 
+int xen_have_vector_callback;
+
 /*
  * Point at some empty memory to start with. We map the real shared_info
  * page as soon as fixmap is up and running.
@@ -1279,6 +1284,31 @@ static void __init init_shared_info(void)
 	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
 }
 
+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);
+}
+
+void do_hvm_pv_evtchn_intr(void)
+{
+	xen_hvm_evtchn_do_upcall(get_irq_regs());
+}
+
+static void xen_callback_vector(void)
+{
+	uint64_t callback_via;
+	if (xen_feature(XENFEAT_hvm_callback_vector)) {
+		callback_via = HVM_CALLBACK_VECTOR(X86_PLATFORM_IPI_VECTOR);
+		xen_set_callback_via(callback_via);
+		x86_platform_ipi_callback = do_hvm_pv_evtchn_intr;
+		xen_have_vector_callback = 1;
+	}
+}
+
 void __init xen_guest_init(void)
 {
 	int r;
@@ -1292,4 +1322,9 @@ void __init xen_guest_init(void)
 		return;
 
 	init_shared_info();
+
+	xen_callback_vector();
+
+	have_vcpu_info_placement = 0;
+	x86_init.irqs.intr_init = xen_init_IRQ;
 }
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index db8f506..3523dbb 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -36,6 +36,8 @@
 #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>
@@ -617,17 +619,13 @@ 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)
+void __xen_evtchn_do_upcall(struct pt_regs *regs)
 {
 	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 +665,26 @@ 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(regs);
+
 	irq_exit();
 	set_irq_regs(old_regs);
+}
 
-	put_cpu();
+void xen_hvm_evtchn_do_upcall(struct pt_regs *regs)
+{
+	__xen_evtchn_do_upcall(regs);
 }
 
 /* Rebind a new event channel to an existing irq. */
@@ -947,5 +961,8 @@ 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())
+		native_init_IRQ();
+	else
+		irq_ctx_init(smp_processor_id());
 }
diff --git a/include/xen/events.h b/include/xen/events.h
index e68d59a..868e5d6 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -56,4 +56,7 @@ void xen_poll_irq(int irq);
 /* Determine the IRQ which is bound to an event channel */
 unsigned irq_from_evtchn(unsigned int evtchn);
 
+void xen_evtchn_do_upcall(struct pt_regs *regs);
+void xen_hvm_evtchn_do_upcall(struct pt_regs *regs);
+
 #endif	/* _XEN_EVENTS_H */
diff --git a/include/xen/hvm.h b/include/xen/hvm.h
index 6b0d418..5940ee5 100644
--- a/include/xen/hvm.h
+++ b/include/xen/hvm.h
@@ -3,6 +3,7 @@
 #define XEN_HVM_H__
 
 #include <xen/interface/hvm/params.h>
+#include <asm/xen/hypercall.h>
 
 static inline int hvm_get_parameter(int idx, uint64_t *value)
 {
@@ -21,4 +22,12 @@ static inline int hvm_get_parameter(int idx, uint64_t *value)
        return r;
 }
 
+int xen_set_callback_via(uint64_t via);
+extern int xen_have_vector_callback;
+
+#define HVM_CALLBACK_VIA_TYPE_VECTOR 0x2
+#define HVM_CALLBACK_VIA_TYPE_SHIFT 56
+#define HVM_CALLBACK_VECTOR(x) (((uint64_t)HVM_CALLBACK_VIA_TYPE_VECTOR)<<\
+                               HVM_CALLBACK_VIA_TYPE_SHIFT | (x))
+
 #endif /* XEN_HVM_H__ */
diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
index f51b641..8ab08b9 100644
--- a/include/xen/interface/features.h
+++ b/include/xen/interface/features.h
@@ -41,6 +41,9 @@
 /* x86: Does this Xen host support the MMU_PT_UPDATE_PRESERVE_AD hypercall? */
 #define XENFEAT_mmu_pt_update_preserve_ad  5
 
+/* x86: Does this Xen host support the HVM callback vector type? */
+#define XENFEAT_hvm_callback_vector        8
+
 #define XENFEAT_NR_SUBMAPS 1
 
 #endif /* __XEN_PUBLIC_FEATURES_H__ */
-- 
1.5.4.3

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