[PATCH v6 09/19] xen/cpufreq: neglect unsupported-mode request from DOM0

[Penny Zheng]

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.zh...@amd.com>
---
v5 -> v6:
- new commit
---
 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;
  
-- 
2.34.1