2021-01-20 13:01:26

by Wei Liu

Subject: [PATCH v5 10/16] 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 <[email protected]>
Signed-off-by: Sunil Muthuswamy <[email protected]>
Co-Developed-by: Lillian Grassin-Drake <[email protected]>
Co-Developed-by: Sunil Muthuswamy <[email protected]>
Signed-off-by: Wei Liu <[email protected]>
---
CPU hotplug and unplug is not yet supported in this setup, so those
paths remain untouched.

v3: Always call native SMP preparation function.
---
arch/x86/kernel/cpu/mshyperv.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index c376d191a260..13d3b6dd21a3 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>

/* Is Linux running as the root partition? */
bool hv_root_partition;
@@ -212,6 +213,32 @@ 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)
@@ -368,6 +395,8 @@ 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

2021-01-26 02:51:34

by Michael Kelley (LINUX)

Subject: RE: [PATCH v5 10/16] x86/hyperv: implement and use hv_smp_prepare_cpus

From: Wei Liu <[email protected]> Sent: Wednesday, January 20, 2021 4:01 AM
>
> 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 <[email protected]>
> Signed-off-by: Sunil Muthuswamy <[email protected]>
> Co-Developed-by: Lillian Grassin-Drake <[email protected]>
> Co-Developed-by: Sunil Muthuswamy <[email protected]>
> Signed-off-by: Wei Liu <[email protected]>
> ---
> CPU hotplug and unplug is not yet supported in this setup, so those
> paths remain untouched.
>
> v3: Always call native SMP preparation function.
> ---
> arch/x86/kernel/cpu/mshyperv.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index c376d191a260..13d3b6dd21a3 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>
>
> /* Is Linux running as the root partition? */
> bool hv_root_partition;
> @@ -212,6 +213,32 @@ 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)
> @@ -368,6 +395,8 @@ 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

Reviewed-by: Michael Kelley <[email protected]>