When kvm is enabled on a core, we migrate all external irq to primary
thread. Since currently, the kvmirq logic is handled by the primary
hwthread.
Todo: this patch lacks re-enable of irqbalance when kvm is disable on
the core
Signed-off-by: Liu Ping Fan <pingf...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/sysfs.c | 39 ++++++++++++++++++++++++++++++++++
arch/powerpc/sysdev/xics/xics-common.c | 12 +++++++++++
2 files changed, 51 insertions(+)
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 67fd2fd..a2595dd 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -552,6 +552,45 @@ static void sysfs_create_dscr_default(void)
if (cpu_has_feature(CPU_FTR_DSCR))
err = device_create_file(cpu_subsys.dev_root,
&dev_attr_dscr_default);
}
+
+#ifdef CONFIG_KVMPPC_ENABLE_SECONDARY
+#define NR_CORES (CONFIG_NR_CPUS/threads_per_core)
+static DECLARE_BITMAP(kvm_on_core, NR_CORES) __read_mostly
+
+static ssize_t show_kvm_enable(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+}
+
+static ssize_t __used store_kvm_enable(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct cpumask stop_cpus;
+ unsigned long core, thr;
+
+ sscanf(buf, "%lx", &core);
+ if (core > NR_CORES)
+ return -1;
+ if (!test_bit(core, &kvm_on_core))
+ for (thr = 1; thr< threads_per_core; thr++)
+ if (cpu_online(thr * threads_per_core + thr))
+ cpumask_set_cpu(thr * threads_per_core + thr,
&stop_cpus);
+
+ stop_machine(xics_migrate_irqs_away_secondary, NULL, &stop_cpus);
+ set_bit(core, &kvm_on_core);
+ return count;
+}
+
+static DEVICE_ATTR(kvm_enable, 0600,
+ show_kvm_enable, store_kvm_enable);
+
+static void sysfs_create_kvm_enable(void)
+{
+ device_create_file(cpu_subsys.dev_root, &dev_attr_kvm_enable);
+}
+#endif
+
#endif /* CONFIG_PPC64 */
#ifdef HAS_PPC_PMC_PA6T
diff --git a/arch/powerpc/sysdev/xics/xics-common.c
b/arch/powerpc/sysdev/xics/xics-common.c
index fe0cca4..68b33d8 100644
--- a/arch/powerpc/sysdev/xics/xics-common.c
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -258,6 +258,18 @@ unlock:
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
}
+
+int xics_migrate_irqs_away_secondary(void *data)
+{
+ int cpu = smp_processor_id();
+ if(cpu%thread_per_core != 0) {
+ WARN(condition, format...);
+ return 0;
+ }
+ /* In fact, if we can migrate the primary, it will be more fine */
+ xics_migrate_irqs_away();
+ return 0;
+}
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_SMP
--
1.8.3.1
--
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