x86/hyperv: fix logical processor creation

Microsoft Hypervisor expects the logical processor index to be the same
as CPU's index during logical processor creation. Using cpu_physical_id
confuses hypervisor's scheduler. That causes the root partition not boot
when core scheduler is used.

This patch removes the call to cpu_physical_id and uses the CPU index
directly for bringing up logical processor. This scheme works for both
classic scheduler and core scheduler.

Fixes: 333abaf5abb3 (x86/hyperv: implement and use hv_smp_prepare_cpus)
Signed-off-by: Praveen Kumar <kumarpraveen@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210531074046.113452-1-kumarpraveen@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 22f1334..4fa0a42 100644 (file)
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -236,7 +236,7 @@ static void __init hv_smp_prepare_cpus(unsigned int 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));
+               ret = hv_call_add_logical_proc(numa_cpu_node(i), i, i);
                BUG_ON(ret);
        }