[PATCH v2 10/17] x86/hyperv: implement and use hv_smp_prepare_cpus

[Wei Liu]

Microsoft Hypervisor requires the root partition to make a few
hypercalls to setup application processors before they can be used.

Signed-off-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx>
Signed-off-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
Co-Developed-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx>
Co-Developed-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
---
CPU hotplug and unplug is not yet supported in this setup, so those
paths remain untouched.
---
 arch/x86/kernel/cpu/mshyperv.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index f7633e1e4c82..4795e54550e6 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -31,6 +31,7 @@
 #include <asm/reboot.h>
 #include <asm/nmi.h>
 #include <clocksource/hyperv_timer.h>
+#include <asm/numa.h>
 
 struct ms_hyperv_info ms_hyperv;
 EXPORT_SYMBOL_GPL(ms_hyperv);
@@ -208,6 +209,30 @@ static void __init hv_smp_prepare_boot_cpu(void)
 	hv_init_spinlocks();
 #endif
 }
+
+static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
+{
+#if defined(CONFIG_X86_64)
+	int i;
+	int ret;
+
+	native_smp_prepare_cpus(max_cpus);
+
+	for_each_present_cpu(i) {
+		if (i == 0)
+			continue;
+		ret = hv_call_add_logical_proc(numa_cpu_node(i), i, cpu_physical_id(i));
+		BUG_ON(ret);
+	}
+
+	for_each_present_cpu(i) {
+		if (i == 0)
+			continue;
+		ret = hv_call_create_vp(numa_cpu_node(i), hv_current_partition_id, i, i);
+		BUG_ON(ret);
+	}
+#endif
+}
 #endif
 
 static void __init ms_hyperv_init_platform(void)
@@ -364,6 +389,8 @@ static void __init ms_hyperv_init_platform(void)
 
 # ifdef CONFIG_SMP
 	smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
+	if (hv_root_partition)
+		smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus;
 # endif
 
 	/*
-- 
2.20.1