[Xen-changelog] [xen staging] x86/sysctl: Clean up XEN_SYSCTL_cpu_hotplug

[patchbot@xxxxxxx]

commit dbe55b5d6a03c72c80d9f6df502927c7dc8db03f
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Mar 29 12:14:37 2019 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu Apr 4 14:32:41 2019 +0100

    x86/sysctl: Clean up XEN_SYSCTL_cpu_hotplug
    
    A future change is going to introduce two more cases.  Instead of opcoding 
the
    XSM checks and contine_hypercall logic, collect the data into local 
variables.
    
    Switch the default return value to -EOPNOTSUPP to distinguish a bad op from 
a
    bad cpu index.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/sysctl.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c
index 1916a3de1b..cff4415ded 100644
--- a/xen/arch/x86/sysctl.c
+++ b/xen/arch/x86/sysctl.c
@@ -137,27 +137,35 @@ long arch_do_sysctl(
     case XEN_SYSCTL_cpu_hotplug:
     {
         unsigned int cpu = sysctl->u.cpu_hotplug.cpu;
+        bool plug;
+        long (*fn)(void *);
+        void *hcpu;
 
         switch ( sysctl->u.cpu_hotplug.op )
         {
         case XEN_SYSCTL_CPU_HOTPLUG_ONLINE:
-            ret = xsm_resource_plug_core(XSM_HOOK);
-            if ( ret )
-                break;
-            ret = continue_hypercall_on_cpu(
-                0, cpu_up_helper, (void *)(unsigned long)cpu);
+            plug = true;
+            fn = cpu_up_helper;
+            hcpu = _p(cpu);
             break;
+
         case XEN_SYSCTL_CPU_HOTPLUG_OFFLINE:
-            ret = xsm_resource_unplug_core(XSM_HOOK);
-            if ( ret )
-                break;
-            ret = continue_hypercall_on_cpu(
-                0, cpu_down_helper, (void *)(unsigned long)cpu);
+            plug = false;
+            fn = cpu_down_helper;
+            hcpu = _p(cpu);
             break;
+
         default:
-            ret = -EINVAL;
+            ret = -EOPNOTSUPP;
             break;
         }
+
+        if ( !ret )
+            ret = plug ? xsm_resource_plug_core(XSM_HOOK)
+                       : xsm_resource_unplug_core(XSM_HOOK);
+
+        if ( !ret )
+            ret = continue_hypercall_on_cpu(0, fn, hcpu);
     }
     break;
 
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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