[PATCH] xen/domain: enable VCPUOP_register_runstate_phys_area hypercall

[torsten.oehlenschlager@xxxxxxxxxxx]

ice@blossom ..............................................................................................................................................................................…/xen 🌸 enable-runstate-phys-area ?

❯ cat 0001-xen-domain-enable-VCPUOP_register_runstate_phys_area.patch

From 416992b30258d34b7cc7bc4f7875719f47618147 Mon Sep 17 00:00:00 2001

From: melanie <torsten.oehlenschlager@xxxxxxxxxxx>

Date: Fri, 12 Dec 2025 20:55:50 +0000

Subject: [PATCH] xen/domain: enable VCPUOP_register_runstate_phys_area

hypercall

The XENFEAT_runstate_phys_area feature is unconditionally advertised to

guests via XENVER_get_features ( see xen/common/kernel.c ),  but the

corresponding VCPUOP_register_runstate_phys_area hypercall was disabled

with a placeholder check that always returned -ENOSYS!

Remove the dead code to enable the hypercall,  making the implementation

consistent with the advertised feature.

Signed-off-by: melanie <torsten.oehlenschlager@xxxxxxxxxxx>

---

xen/common/domain.c | 4 ----

1 file changed, 4 deletions(-)

diff --git a/xen/common/domain.c b/xen/common/domain.c

index 93c71bc766..3ae8d41cf2 100644

--- a/xen/common/domain.c

+++ b/xen/common/domain.c

@@ -2284,10 +2284,6 @@ long common_vcpu_op(int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)

     {

         struct vcpu_register_runstate_memory_area area;

-        rc = -ENOSYS;

-        if ( 0 /* TODO: Dom's XENFEAT_runstate_phys_area setting */ )

-            break;

-

         rc = -EFAULT;

         if ( copy_from_guest(&area.addr.p, arg, 1) )

             break;

--

--