From ae67b0add336d77e106541e552eadf03414f2b63 Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Thu, 21 May 2009 17:09:01 -0700
Subject: [PATCH 23/25] smp_send_reschedule compat

smp_send_reschedule was exported (via smp_ops) in v2.6.24.
Create a compat function which schedules the IPI to keventd context,
in case interrupts are disabled, for kernels < 2.6.24.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
(cherry picked from commit kvm-kmod: 629715b550be23a1ce4f921f1c7d99e35bc940a5)
Signed-off-by: Chris Wright <chrisw@redhat.com>
Bugzilla: 498085
Message-Id: <1242950943-30180-24-git-send-email-chrisw@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
RH-Upstream-status: applied
Acked-by: Juan Quintela <quintela@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Don Dutile <ddutile@redhat.com>
---
 kernel/external-module-compat-comm.h |    6 ++++
 kernel/external-module-compat.c      |   52 ++++++++++++++++++++++++++++++++++
 kernel/ia64/hack-module.awk          |    2 +-
 kernel/x86/hack-module.awk           |    2 +-
 4 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/kernel/external-module-compat-comm.h b/kernel/external-module-compat-comm.h
index d9605ff..29934e5 100644
--- a/kernel/external-module-compat-comm.h
+++ b/kernel/external-module-compat-comm.h
@@ -224,6 +224,12 @@ int kvm_smp_call_function_mask(cpumask_t mask, void (*func) (void *info),
 
 #define smp_call_function_mask kvm_smp_call_function_mask
 
+void kvm_smp_send_reschedule(int cpu);
+
+#else
+
+#define kvm_smp_send_reschedule smp_send_reschedule
+
 #endif
 
 /* empty_zero_page isn't exported in all kernels */
diff --git a/kernel/external-module-compat.c b/kernel/external-module-compat.c
index c0a0355..390a140 100644
--- a/kernel/external-module-compat.c
+++ b/kernel/external-module-compat.c
@@ -206,6 +206,58 @@ out:
 	return 0;
 }
 
+#include <linux/workqueue.h>
+
+static void vcpu_kick_intr(void *info)
+{
+}
+
+struct kvm_kick {
+	int cpu;
+	struct work_struct work;
+};
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
+static void kvm_do_smp_call_function(void *data)
+{
+	int me;
+	struct kvm_kick *kvm_kick = data;
+#else
+static void kvm_do_smp_call_function(struct work_struct *work)
+{
+	int me;
+	struct kvm_kick *kvm_kick = container_of(work, struct kvm_kick, work);
+#endif
+	me = get_cpu();
+
+	if (kvm_kick->cpu != me)
+		smp_call_function_single(kvm_kick->cpu, vcpu_kick_intr,
+					 NULL, 0);
+	kfree(kvm_kick);
+	put_cpu();
+}
+
+void kvm_queue_smp_call_function(int cpu)
+{
+	struct kvm_kick *kvm_kick = kmalloc(sizeof(struct kvm_kick), GFP_ATOMIC);
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
+	INIT_WORK(&kvm_kick->work, kvm_do_smp_call_function, kvm_kick);
+#else
+	INIT_WORK(&kvm_kick->work, kvm_do_smp_call_function);
+#endif
+
+	schedule_work(&kvm_kick->work);
+}
+
+void kvm_smp_send_reschedule(int cpu)
+{
+	if (irqs_disabled()) {
+		kvm_queue_smp_call_function(cpu);
+		return;
+	}
+	smp_call_function_single(cpu, vcpu_kick_intr, NULL, 0);
+}
 #endif
 
 /* manually export hrtimer_init/start/cancel */
diff --git a/kernel/ia64/hack-module.awk b/kernel/ia64/hack-module.awk
index 2eb557a..5240f5b 100644
--- a/kernel/ia64/hack-module.awk
+++ b/kernel/ia64/hack-module.awk
@@ -1,4 +1,4 @@
-BEGIN { split("INIT_WORK on_each_cpu smp_call_function " \
+BEGIN { split("INIT_WORK on_each_cpu smp_call_function smp_send_reschedule " \
 	      "hrtimer_add_expires_ns hrtimer_get_expires " \
 	      "hrtimer_get_expires_ns hrtimer_start_expires " \
 	      "hrtimer_expires_remaining " \
diff --git a/kernel/x86/hack-module.awk b/kernel/x86/hack-module.awk
index e07678f..5a49183 100644
--- a/kernel/x86/hack-module.awk
+++ b/kernel/x86/hack-module.awk
@@ -1,7 +1,7 @@
 BEGIN { split("INIT_WORK tsc_khz desc_struct ldttss_desc64 desc_ptr " \
 	      "hrtimer_add_expires_ns hrtimer_get_expires " \
 	      "hrtimer_get_expires_ns hrtimer_start_expires " \
-	      "hrtimer_expires_remaining " \
+	      "hrtimer_expires_remaining smp_send_reschedule " \
 	      "on_each_cpu relay_open request_irq free_irq get_user_pages_fast" , compat_apis); }
 
 /^int kvm_init\(/ { anon_inodes = 1 }
-- 
1.6.3.rc4.29.g8146