[xen staging] xen/cpufreq: neglect unsupported-mode request from DOM0

[patchbot@xxxxxxx]

commit 365e660f0ff4a20bdffb14181ebd4e66707acb6b
Author:     Penny Zheng <Penny.Zheng@xxxxxxx>
AuthorDate: Thu Jul 17 08:57:41 2025 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Jul 17 08:57:41 2025 +0200

    xen/cpufreq: neglect unsupported-mode request from DOM0
    
    DOM0 could deliever whatever performance statistic (Px, _CPC) it parses, it 
is
    Xen's responsibility to decide which one it shall accept.
    Xen rely on XEN_PROCESSOR_PM_xxx flag to tell which mode ( Px or CPPC )
    current cpufreq driver supports, and accepts relative info. It will neglect
    unsupported-mode request and yields success.
    
    Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
    Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/platform_hypercall.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/platform_hypercall.c 
b/xen/arch/x86/platform_hypercall.c
index 90abd3197f..3eba791889 100644
--- a/xen/arch/x86/platform_hypercall.c
+++ b/xen/arch/x86/platform_hypercall.c
@@ -539,9 +539,14 @@ ret_t do_platform_op(
         case XEN_PM_PX:
             if ( !(xen_processor_pmbits & XEN_PROCESSOR_PM_PX) )
             {
-                ret = -ENOSYS;
+                /*
+                 * Neglect Px-info when registered cpufreq driver
+                 * isn't in Px mode
+                 */
+                ret = 0;
                 break;
             }
+
             ret = set_px_pminfo(op->u.set_pminfo.id, &op->u.set_pminfo.u.perf);
             break;
  
--
generated by git-patchbot for /home/xen/git/xen.git#staging