[02/16] xen/x86: Move freeze/thaw_domains into common files

Commit Message

Mykola Kvach March 5, 2025, 9:11 a.m. UTC

From: Mirela Simonovic <[e-mail]>

These functions will be reused by suspend/resume support for ARM.

Signed-off-by: Mirela Simonovic <[e-mail]>
Signed-off-by: Saeed Nowshadi <[e-mail]>
Signed-off-by: Mykyta Poturai <[e-mail]>
Signed-off-by: Mykola Kvach <[e-mail]>
---
 xen/arch/x86/acpi/power.c | 29 -----------------------------
 xen/common/domain.c       | 30 ++++++++++++++++++++++++++++++
 xen/include/xen/sched.h   |  3 +++
 3 files changed, 33 insertions(+), 29 deletions(-)

Comments

Jan Beulich March 5, 2025, 4:48 p.m. UTC | #1

On 05.03.2025 10:11, Mykola Kvach wrote:
> From: Mirela Simonovic <[e-mail]>
> 
> These functions will be reused by suspend/resume support for ARM.

And until then they are going to violate the Misra rule requiring there
to not be unreachable code.

> --- a/xen/common/domain.c
> +++ b/xen/common/domain.c
> @@ -2259,6 +2259,36 @@ int continue_hypercall_on_cpu(
>      return 0;
>  }
>  
> +
> +void freeze_domains(void)

Nit: No double blank lines please.

> +{
> +    struct domain *d;
> +
> +    rcu_read_lock(&domlist_read_lock);
> +    /*
> +     * Note that we iterate in order of domain-id. Hence we will pause dom0
> +     * first which is required for correctness (as only dom0 can add domains to
> +     * the domain list). Otherwise we could miss concurrently-created domains.
> +     */
> +    for_each_domain ( d )
> +        domain_pause(d);
> +    rcu_read_unlock(&domlist_read_lock);
> +
> +    scheduler_disable();

When made generally available I'm unsure having this and ...

> +}
> +
> +void thaw_domains(void)
> +{
> +    struct domain *d;
> +
> +    scheduler_enable();

... this here is a good idea. Both scheduler operations aren't related
to what the function names say is being done here.

Jan

Patch

diff --git a/xen/arch/x86/acpi/power.c b/xen/arch/x86/acpi/power.c
index d0b67614d5..f38398827e 100644
--- a/xen/arch/x86/acpi/power.c
+++ b/xen/arch/x86/acpi/power.c
@@ -137,35 +137,6 @@  static void device_power_up(enum dev_power_saved saved)
     }
 }
 
-static void freeze_domains(void)
-{
-    struct domain *d;
-
-    rcu_read_lock(&domlist_read_lock);
-    /*
-     * Note that we iterate in order of domain-id. Hence we will pause dom0
-     * first which is required for correctness (as only dom0 can add domains to
-     * the domain list). Otherwise we could miss concurrently-created domains.
-     */
-    for_each_domain ( d )
-        domain_pause(d);
-    rcu_read_unlock(&domlist_read_lock);
-
-    scheduler_disable();
-}
-
-static void thaw_domains(void)
-{
-    struct domain *d;
-
-    scheduler_enable();
-
-    rcu_read_lock(&domlist_read_lock);
-    for_each_domain ( d )
-        domain_unpause(d);
-    rcu_read_unlock(&domlist_read_lock);
-}
-
 static void acpi_sleep_prepare(u32 state)
 {
     void *wakeup_vector_va;
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 0c4cc77111..49ff84d2f5 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -2259,6 +2259,36 @@  int continue_hypercall_on_cpu(
     return 0;
 }
 
+
+void freeze_domains(void)
+{
+    struct domain *d;
+
+    rcu_read_lock(&domlist_read_lock);
+    /*
+     * Note that we iterate in order of domain-id. Hence we will pause dom0
+     * first which is required for correctness (as only dom0 can add domains to
+     * the domain list). Otherwise we could miss concurrently-created domains.
+     */
+    for_each_domain ( d )
+        domain_pause(d);
+    rcu_read_unlock(&domlist_read_lock);
+
+    scheduler_disable();
+}
+
+void thaw_domains(void)
+{
+    struct domain *d;
+
+    scheduler_enable();
+
+    rcu_read_lock(&domlist_read_lock);
+    for_each_domain ( d )
+        domain_unpause(d);
+    rcu_read_unlock(&domlist_read_lock);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 037c83fda2..177784e6da 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -1059,6 +1059,9 @@  static inline struct vcpu *domain_vcpu(const struct domain *d,
     return vcpu_id >= d->max_vcpus ? NULL : d->vcpu[idx];
 }
 
+void freeze_domains(void);
+void thaw_domains(void);
+
 void cpu_init(void);
 
 /*