Arch-specific domain_set_time_offset() is responisble for
XEN_DOMCTL_settimeoffset domctl-op, and shall be wrapped with
CONFIG_MGMT_HYPERCALLS
Wrap XEN_DOMCTL_settimeoffset-case transiently with CONFIG_MGMT_HYPERCALLS,
and it will be removed when introducing CONFIG_MGMT_HYPERCALLS on the
common/domctl.c in the last.

Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>
---
v1 -> v2:
- adapt to changes of "unify DOMCTL to MGMT_HYPERCALLS"
- wrap XEN_DOMCTL_settimeoffset-case transiently
---
 xen/arch/arm/time.c | 2 ++
 xen/arch/x86/time.c | 2 ++
 xen/common/domctl.c | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
index e74d30d258..dfed0b0ab8 100644
--- a/xen/arch/arm/time.c
+++ b/xen/arch/arm/time.c
@@ -365,12 +365,14 @@ void force_update_vcpu_system_time(struct vcpu *v)
     update_vcpu_system_time(v);
 }
 
+#ifdef CONFIG_MGMT_HYPERCALLS
 void domain_set_time_offset(struct domain *d, int64_t time_offset_seconds)
 {
     d->time_offset.seconds = time_offset_seconds;
     d->time_offset.set = true;
     /* XXX update guest visible wallclock time */
 }
+#endif /* CONFIG_MGMT_HYPERCALLS */
 
 static int cpu_time_callback(struct notifier_block *nfb,
                              unsigned long action,
diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index 59129f419d..e7394ce8cf 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -1841,6 +1841,7 @@ static void update_domain_rtc(void)
     rcu_read_unlock(&domlist_read_lock);
 }
 
+#ifdef CONFIG_MGMT_HYPERCALLS
 void domain_set_time_offset(struct domain *d, int64_t time_offset_seconds)
 {
     d->time_offset.seconds = time_offset_seconds;
@@ -1849,6 +1850,7 @@ void domain_set_time_offset(struct domain *d, int64_t time_offset_seconds)
         rtc_update_clock(d);
     update_domain_wallclock_time(d);
 }
+#endif /* CONFIG_MGMT_HYPERCALLS */
 
 int cpu_frequency_change(u64 freq)
 {
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 6048a87826..776bf7b8e2 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -748,9 +748,11 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
         break;
     }
 
+#ifdef CONFIG_MGMT_HYPERCALLS
     case XEN_DOMCTL_settimeoffset:
         domain_set_time_offset(d, op->u.settimeoffset.time_offset_seconds);
         break;
+#endif /* CONFIG_MGMT_HYPERCALLS */
 
     case XEN_DOMCTL_set_target:
     {
-- 
2.34.1

On 10.09.2025 09:38, Penny Zheng wrote:
> Arch-specific domain_set_time_offset() is responisble for
> XEN_DOMCTL_settimeoffset domctl-op, and shall be wrapped with
> CONFIG_MGMT_HYPERCALLS
> Wrap XEN_DOMCTL_settimeoffset-case transiently with CONFIG_MGMT_HYPERCALLS,
> and it will be removed when introducing CONFIG_MGMT_HYPERCALLS on the
> common/domctl.c in the last.

As I keep seeing this same wording, I finally have to say something there as
well: For one, the last patch doesn't introduce CONFIG_MGMT_HYPERCALLS on
common/domctl.c. In instead makes the building of common/domctl.o conditional
upon that control being set. And then, "in the last" (btw - last what?) is as
unhelpful as "in the next patch" or "in the previous patch". When writing
commit messages, you want to make sure they make sense all on their own, no
matter in what order patches are committed (in particular possibly piecemeal
and interspersed with other patches). Possible replacement wording:

"Wrap XEN_DOMCTL_settimeoffset-case transiently with CONFIG_MGMT_HYPERCALLS,
 which will be removed again once common/domctl.o's building as a whole
 becomes dependent upon that setting."

> Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>

Acked-by: Jan Beulich <jbeulich@suse.com> # x86

(i.e. specifically _not_ the common code change)

I also wonder what our (Misra related) position is towards leaving declarations
around in cases like this one, where they're not in support of DCE-ing of code.

Jan

On Wed, 10 Sep 2025, Penny Zheng wrote:
> Arch-specific domain_set_time_offset() is responisble for
> XEN_DOMCTL_settimeoffset domctl-op, and shall be wrapped with
> CONFIG_MGMT_HYPERCALLS
> Wrap XEN_DOMCTL_settimeoffset-case transiently with CONFIG_MGMT_HYPERCALLS,
> and it will be removed when introducing CONFIG_MGMT_HYPERCALLS on the
> common/domctl.c in the last.
> 
> Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>

riscv has only a stub so:

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>