[Xen-devel] [RFC v2 11/15] vmx: Add a global wake-up vector for VT-d Posted-Interrupts

[Feng Wu <feng.wu@xxxxxxxxx>]

This patch adds a global vector which is used to wake up
the blocked vCPU when an interrupt is being posted to it.

Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
Suggested-by: Yang Zhang <yang.z.zhang@xxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vmx.c        | 31 +++++++++++++++++++++++++++++++
 xen/include/asm-x86/hvm/hvm.h     |  1 +
 xen/include/asm-x86/hvm/vmx/vmx.h |  3 +++
 xen/include/xen/sched.h           |  2 ++
 4 files changed, 37 insertions(+)

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 2451ca5..0e71d7e 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -90,6 +90,7 @@ DEFINE_PER_CPU(struct list_head, blocked_vcpu);
 DEFINE_PER_CPU(spinlock_t, blocked_vcpu_lock);
 
 uint8_t __read_mostly posted_intr_vector;
+uint8_t __read_mostly pi_wakeup_vector;
 
 static int vmx_domain_initialise(struct domain *d)
 {
@@ -132,6 +133,8 @@ static int vmx_vcpu_initialise(struct vcpu *v)
     if ( v->vcpu_id == 0 )
         v->arch.user_regs.eax = 1;
 
+    INIT_LIST_HEAD(&v->blocked_vcpu_list);
+
     return 0;
 }
 
@@ -1835,11 +1838,17 @@ const struct hvm_function_table * __init start_vmx(void)
     }
 
     if ( cpu_has_vmx_posted_intr_processing )
+    {
         alloc_direct_apic_vector(&posted_intr_vector, event_check_interrupt);
+
+        if ( iommu_intpost )
+            alloc_direct_apic_vector(&pi_wakeup_vector, pi_wakeup_interrupt);
+    }
     else
     {
         vmx_function_table.deliver_posted_intr = NULL;
         vmx_function_table.sync_pir_to_irr = NULL;
+        vmx_function_table.pi_desc_update = NULL;
     }
 
     if ( cpu_has_vmx_ept
@@ -3262,6 +3271,28 @@ void vmx_vmenter_helper(const struct cpu_user_regs *regs)
 }
 
 /*
+ * Handle VT-d posted-interrupt when VCPU is blocked.
+ */
+void pi_wakeup_interrupt(struct cpu_user_regs *regs)
+{
+    struct vcpu *v;
+    unsigned int cpu = smp_processor_id();
+
+    spin_lock(&per_cpu(blocked_vcpu_lock, cpu));
+    list_for_each_entry(v, &per_cpu(blocked_vcpu, cpu),
+                    blocked_vcpu_list) {
+        struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc;
+
+        if ( pi_desc->on == 1 )
+            tasklet_schedule(&v->vcpu_wakeup_tasklet);
+    }
+    spin_unlock(&per_cpu(blocked_vcpu_lock, cpu));
+
+    ack_APIC_irq();
+    this_cpu(irq_count)++;
+}
+
+/*
  * Local variables:
  * mode: C
  * c-file-style: "BSD"
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 77eeac5..e621c30 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -195,6 +195,7 @@ struct hvm_function_table {
     void (*deliver_posted_intr)(struct vcpu *v, u8 vector);
     void (*sync_pir_to_irr)(struct vcpu *v);
     void (*handle_eoi)(u8 vector);
+    void (*pi_desc_update)(struct vcpu *v, int old_state);
 
     /*Walk nested p2m  */
     int (*nhvm_hap_walk_L1_p2m)(struct vcpu *v, paddr_t L2_gpa,
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h 
b/xen/include/asm-x86/hvm/vmx/vmx.h
index 0d11f9c..3adf776 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -34,6 +34,7 @@ DECLARE_PER_CPU(struct list_head, blocked_vcpu);
 DECLARE_PER_CPU(spinlock_t, blocked_vcpu_lock);
 
 extern uint8_t posted_intr_vector;
+extern uint8_t pi_wakeup_vector;
 
 typedef union {
     struct {
@@ -552,6 +553,8 @@ int alloc_p2m_hap_data(struct p2m_domain *p2m);
 void free_p2m_hap_data(struct p2m_domain *p2m);
 void p2m_init_hap_data(struct p2m_domain *p2m);
 
+void pi_wakeup_interrupt(struct cpu_user_regs *regs);
+
 /* EPT violation qualifications definitions */
 #define _EPT_READ_VIOLATION         0
 #define EPT_READ_VIOLATION          (1UL<<_EPT_READ_VIOLATION)
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index fd9e01e..4a7e6b3 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -148,6 +148,8 @@ struct vcpu
 
     struct vcpu     *next_in_list;
 
+    struct list_head blocked_vcpu_list;
+
     s_time_t         periodic_period;
     s_time_t         periodic_last_event;
     struct timer     periodic_timer;
-- 
2.1.0


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel