The patch introduces stub header needed for full Xen build.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
 xen/include/asm-generic/cpufeature.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 xen/include/asm-generic/cpufeature.h

diff --git a/xen/include/asm-generic/cpufeature.h b/xen/include/asm-generic/cpufeature.h
new file mode 100644
index 0000000000..86e2a8b455
--- /dev/null
+++ b/xen/include/asm-generic/cpufeature.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_CPUFEATURE_H__
+#define __ASM_GENERIC_CPUFEATURE_H__
+
+#ifndef __ASSEMBLY__
+
+static inline int cpu_nr_siblings(unsigned int cpu)
+{
+    return 1;
+}
+
+#endif
+
+#endif /* __ASM_GENERIC_CPUFEATURE_H__  */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.41.0

On 14.09.2023 16:56, Oleksii Kurochko wrote:
> --- /dev/null
> +++ b/xen/include/asm-generic/cpufeature.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef __ASM_GENERIC_CPUFEATURE_H__
> +#define __ASM_GENERIC_CPUFEATURE_H__
> +
> +#ifndef __ASSEMBLY__
> +
> +static inline int cpu_nr_siblings(unsigned int cpu)
> +{
> +    return 1;
> +}
> +
> +#endif
> +
> +#endif /* __ASM_GENERIC_CPUFEATURE_H__  */

I'm not convinced an arch can get away without such a header. Certainly
RISC-V and PPC can't, with all their ISA extensions that already exist
(part of which will want making use of, others may simply want exposing
to guests).

Jan

On Thu, 2023-10-19 at 11:11 +0200, Jan Beulich wrote:
> I'm not convinced an arch can get away without such a header.
> Certainly
> RISC-V and PPC can't, with all their ISA extensions that already
> exist
> (part of which will want making use of, others may simply want
> exposing
> to guests).
Yes, it looks like you are right. I forgot about a considerable amount
of ISA.

By this patch series, I tried to move headers to asm-generic to build
minimal Xen without introducing the stub cpu_nr_siblings(unsigned int
cpu) for each new arch. But taking into account that likely this header
will be re-introduced for an arch, there is probably no sense to have
it in asm-generic.

~ Oleksii