If your Linux kernel is below 2.6.27, don't use
smp_call_function_xxx(), use the function preempt_safe_send_ipi()
defined here instead.
---------------------------------------------------------------------------------------------------------
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index b43c4ef..b8ebe93 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -13,7 +13,7 @@ endif
EXTRA_CFLAGS += -Ivirt/kvm -Iarch/x86/kvm
-kvm-objs := $(common-objs) x86.o mmu.o x86_emulate.o i8259.o irq.o lapic.o \
+kvm-objs := $(common-objs) ipi.o trace.o schedule.o sched_credit.o
x86.o mmu.o x86_emulate.o i8259.o irq.o lapic.o \
i8254.o timer.o
obj-$(CONFIG_KVM) += kvm.o
kvm-intel-objs = vmx.o
diff --git a/arch/x86/kvm/ipi.c b/arch/x86/kvm/ipi.c
new file mode 100644
index 0000000..a110e7e
--- /dev/null
+++ b/arch/x86/kvm/ipi.c
@@ -0,0 +1,129 @@
+#include <linux/kvm_host.h>
+#include <linux/schedule.h>
+#include <linux/sched-if.h>
+#include <linux/ipi.h>
+#include <linux/trace.h>
+
+struct ipi_info{
+ cpumask_t dest;
+ void (*func)(void *); /* the function to be called*/
+ void *data; /* the function argument */
+ int sync;
+};
+#define MAX_PENDING_IPI 10
+
+#define NOT_SENDING_IPI 0
+#define SENDING_IPI ((unsigned int)(-1))
+struct pending_ipis {
+ struct ipi_info* pi;
+ volatile unsigned int cons;
+ volatile unsigned int prod;
+ volatile unsigned int sending_ipi;
+ volatile bool tasklet_running;
+};
+DEFINE_PER_CPU(struct pending_ipis, pending_ipi);
+DEFINE_PER_CPU(spinlock_t, ipi_lock);
+
+void init_pending_ipi_buf(int cpu)
+{
+ struct pending_ipis* pendings = &per_cpu(pending_ipi, cpu);
+
+ pendings->cons = pendings->prod = 0;
+ pendings->sending_ipi = NOT_SENDING_IPI;
+ pendings->tasklet_running = false;
+ pendings->pi = kzalloc(sizeof(struct ipi_info)*MAX_PENDING_IPI,
GFP_KERNEL);
+ spin_lock_init(&per_cpu(ipi_lock, cpu));
+ BUG_ON(!pendings->pi);
+}
+void destroy_pending_ipi_buf(int cpu)
+{
+ struct pending_ipis* pendings = &per_cpu(pending_ipi, cpu);
+ if(pendings->prod != pendings->cons)
+ printk(" pendings are %d %d\n", pendings->prod, pendings->cons);
+ kfree(pendings->pi);
+}
+int insert_pending_ipi(int cpu, cpumask_t mask, void (*func)(void*),
void* data, int sync)
+{
+ struct pending_ipis* pendings = &per_cpu(pending_ipi, cpu);
+ struct ipi_info *pend_ipi_info;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if(pendings->prod == (pendings->cons + MAX_PENDING_IPI)){
+ printk("pending IPI buffer full!\n");
+ local_irq_restore(flags);
+ return 1;
+ }
+ pend_ipi_info = pendings->pi + (pendings->prod % MAX_PENDING_IPI);
+ pendings->prod++;
+
+ BUG_ON(!pendings->pi);
+ BUG_ON(!pend_ipi_info);
+
+ pend_ipi_info->func = func;
+ pend_ipi_info->dest = mask;
+ pend_ipi_info->data = data;
+ pend_ipi_info->sync = sync;
+ local_irq_restore(flags);
+ return 0;
+}
+bool pending_ipi_buf_empty(int cpu)
+{
+ struct pending_ipis* pi;
+ pi = &per_cpu(pending_ipi, cpu);
+ return (pi->prod <= pi->cons);
+}
+extern bool shutting_down;
+void inject_pending_ipi(int cpu)
+{
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO-2};
+ sched_setscheduler(current, SCHED_RR, ¶m);
+ struct schedule_data *sd = &per_cpu(schedule_data, cpu);
+ struct pending_ipis *pi = &per_cpu(pending_ipi, cpu);
+ kvm_sched_setaffinity(current->pid, cpumask_of_cpu(cpu));
+
+ while(1) {
+ wait_event_interruptible(sd->ipi_wq, (pi->cons < pi->prod) ||
sd->ipi_quit);
+
+ if(sd->ipi_quit) break;
+ preempt_disable();
+ if(cmpxchg(&pi->sending_ipi, NOT_SENDING_IPI, SENDING_IPI) !=
NOT_SENDING_IPI){
+ printk("impossible case!\n");
+ preempt_enable();
+ continue;
+ }
+
+ /* pi->prod != pi->cons not OK? */
+ while(pi->prod > pi->cons){
+ struct ipi_info *ipi = pi->pi+ (pi->cons % MAX_PENDING_IPI);
+ smp_call_function_mask(ipi->dest, ipi->func, ipi->data, ipi->sync);
+ pi->cons++;
+ }
+ barrier();
+ pi->sending_ipi = NOT_SENDING_IPI;
+ preempt_enable();
+ barrier();
+ }
+ sd->ipi_quit = false;
+ printk("ipi thread %d quitted\n", cpu);
+}
+
+void preempt_safe_send_ipi(cpumask_t mask, void (*func)(void*), void*
data, int sync)
+{
+ unsigned long flags;
+ int cpu = get_cpu();
+ struct pending_ipis* pi = &per_cpu(pending_ipi, cpu);;
+
+ if(cmpxchg(&pi->sending_ipi, NOT_SENDING_IPI, SENDING_IPI) !=
NOT_SENDING_IPI) {
+ BUG_ON(1);
+ put_cpu();
+ return;
+ }
+ smp_call_function_mask(mask, func, data, sync);
+
+ barrier();
+ pi->sending_ipi = NOT_SENDING_IPI;
+ TRACE_2D(TRC_SEND_IPI, cpu, __LINE__);
+ put_cpu();
+}
+EXPORT_SYMBOL_GPL(preempt_safe_send_ipi);
--
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