[PATCH RFC v1 33/74] x86/guest: enable event channels upcalls

[Wei Liu <wei.liu2@citrix.com>]

From: Sergey Dyasli <sergey.dyasli@citrix.com>

Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
 xen/arch/x86/guest/xen.c              | 74 +++++++++++++++++++++++++++++++++++
 xen/arch/x86/smpboot.c                |  4 ++
 xen/include/asm-x86/guest/hypercall.h | 17 ++++++++
 xen/include/asm-x86/guest/xen.h       |  5 +++
 4 files changed, 100 insertions(+)

diff --git a/xen/arch/x86/guest/xen.c b/xen/arch/x86/guest/xen.c
index 594eae0828..781bfa493b 100644
--- a/xen/arch/x86/guest/xen.c
+++ b/xen/arch/x86/guest/xen.c
@@ -21,6 +21,7 @@
 #include <xen/init.h>
 #include <xen/types.h>
 
+#include <asm/apic.h>
 #include <asm/guest.h>
 #include <asm/msr.h>
 #include <asm/processor.h>
@@ -30,6 +31,7 @@
 bool xen_guest;
 
 static uint32_t xen_cpuid_base;
+static uint8_t evtchn_upcall_vector;
 extern char hypercall_page[];
 
 static void __init find_xen_leaves(void)
@@ -91,9 +93,81 @@ static void map_shared_info(struct e820map *e820)
     set_fixmap(FIX_XEN_SHARED_INFO, frame);
 }
 
+static void xen_evtchn_upcall(struct cpu_user_regs *regs)
+{
+    unsigned int cpu = smp_processor_id();
+    struct vcpu_info *vcpu_info = &XEN_shared_info->vcpu_info[cpu];
+
+    vcpu_info->evtchn_upcall_pending = 0;
+    xchg(&vcpu_info->evtchn_pending_sel, 0);
+
+    ack_APIC_irq();
+}
+
+static void ap_setup_event_channels(bool clear)
+{
+    unsigned int i, cpu = smp_processor_id();
+    struct vcpu_info *vcpu_info = &XEN_shared_info->vcpu_info[cpu];
+    int rc;
+
+    ASSERT(evtchn_upcall_vector);
+    ASSERT(cpu < ARRAY_SIZE(XEN_shared_info->vcpu_info));
+
+    if ( !clear )
+    {
+        /*
+         * This is necessary to ensure that a CPU will be interrupted in case
+         * of an event channel notification.
+         */
+        ASSERT(vcpu_info->evtchn_upcall_pending == 0);
+        ASSERT(vcpu_info->evtchn_pending_sel == 0);
+    }
+
+    rc = xen_hypercall_set_evtchn_upcall_vector(cpu, evtchn_upcall_vector);
+    if ( rc )
+        panic("Unable to set evtchn upcall vector: %d", rc);
+
+    if ( clear )
+    {
+        /*
+         * Clear any pending upcall bits. This makes us effectively ignore any
+         * previous upcalls which might be suboptimal.
+         */
+        vcpu_info->evtchn_upcall_pending = 0;
+        xchg(&vcpu_info->evtchn_pending_sel, 0);
+
+        /*
+         * evtchn_pending can be cleared only on the boot CPU because it's
+         * located in a shared structure.
+         */
+        for ( i = 0; i < 8; i++ )
+            xchg(&XEN_shared_info->evtchn_pending[i], 0);
+    }
+}
+
+static void __init init_evtchn(void)
+{
+    unsigned int i;
+
+    alloc_direct_apic_vector(&evtchn_upcall_vector, xen_evtchn_upcall);
+
+    /* Mask all upcalls */
+    for ( i = 0; i < 8; i++ )
+        xchg(&XEN_shared_info->evtchn_mask[i], ~0ul);
+
+    ap_setup_event_channels(true);
+}
+
 void __init hypervisor_early_setup(struct e820map *e820)
 {
     map_shared_info(e820);
+
+    init_evtchn();
+}
+
+void hypervisor_ap_setup(void)
+{
+    ap_setup_event_channels(false);
 }
 
 /*
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 7b97ff86cb..9a9fbc6ee0 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -45,6 +45,7 @@
 #include <mach_apic.h>
 #include <mach_wakecpu.h>
 #include <smpboot_hooks.h>
+#include <asm/guest.h>
 
 /* Override macros from asm/page.h to make them work with mfn_t */
 #undef mfn_to_page
@@ -372,6 +373,9 @@ void start_secondary(void *unused)
     cpumask_set_cpu(cpu, &cpu_online_map);
     unlock_vector_lock();
 
+    if ( xen_guest )
+        hypervisor_ap_setup();
+
     /* We can take interrupts now: we're officially "up". */
     local_irq_enable();
     mtrr_ap_init();
diff --git a/xen/include/asm-x86/guest/hypercall.h b/xen/include/asm-x86/guest/hypercall.h
index d5fe535c03..d6d4d1946b 100644
--- a/xen/include/asm-x86/guest/hypercall.h
+++ b/xen/include/asm-x86/guest/hypercall.h
@@ -23,6 +23,7 @@
 
 #include <public/xen.h>
 #include <public/sched.h>
+#include <public/hvm/hvm_op.h>
 
 #ifdef CONFIG_XEN_GUEST
 
@@ -96,6 +97,11 @@ static inline long xen_hypercall_memory_op(unsigned int cmd, void *arg)
     return _hypercall64_2(long, __HYPERVISOR_memory_op, cmd, arg);
 }
 
+static inline long xen_hypercall_hvm_op(unsigned int op, void *arg)
+{
+    return _hypercall64_2(long, __HYPERVISOR_hvm_op, op, arg);
+}
+
 /*
  * Higher level hypercall helpers
  */
@@ -111,6 +117,17 @@ static inline long xen_hypercall_shutdown(unsigned int reason)
     return xen_hypercall_sched_op(SCHEDOP_shutdown, &reason);
 }
 
+static inline long xen_hypercall_set_evtchn_upcall_vector(
+    unsigned int cpu, unsigned int vector)
+{
+    struct xen_hvm_evtchn_upcall_vector a = {
+        .vcpu = cpu,
+        .vector = vector,
+    };
+
+    return xen_hypercall_hvm_op(HVMOP_set_evtchn_upcall_vector, &a);
+}
+
 #else /* CONFIG_XEN_GUEST */
 
 static inline void xen_hypercall_console_write(
diff --git a/xen/include/asm-x86/guest/xen.h b/xen/include/asm-x86/guest/xen.h
index 2f3bcd2fe4..56cabb1934 100644
--- a/xen/include/asm-x86/guest/xen.h
+++ b/xen/include/asm-x86/guest/xen.h
@@ -32,6 +32,7 @@ extern bool xen_guest;
 
 void probe_hypervisor(void);
 void hypervisor_early_setup(struct e820map *e820);
+void hypervisor_ap_setup(void);
 
 #else
 
@@ -42,6 +43,10 @@ static inline void hypervisor_early_setup(struct e820map *e820)
 {
     ASSERT_UNREACHABLE();
 };
+static inline void hypervisor_ap_setup(void)
+{
+    ASSERT_UNREACHABLE();
+};
 
 #endif /* CONFIG_XEN_GUEST */
 #endif /* __X86_GUEST_XEN_H__ */
-- 
2.11.0


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