x86/hyperv: implement and use hv_smp_prepare_cpus

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@microsoft.com>
Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com>
Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-11-wei.liu@kernel.org

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 39a4b45..e88bc29 100644 (file)
--- 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>
 
 /* Is Linux running as the root partition? */
 bool hv_root_partition;
@@ -230,6 +231,32 @@ static void __init hv_smp_prepare_boot_cpu(void)
        hv_init_spinlocks();
 #endif
 }
+
+static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
+{
+#ifdef CONFIG_X86_64
+       int i;
+       int ret;
+#endif
+
+       native_smp_prepare_cpus(max_cpus);
+
+#ifdef CONFIG_X86_64
+       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)
@@ -395,6 +422,8 @@ 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
 
        /*