Re: [PATCH 16/24] XSM: suppress hypercall when XSM=n

On 7/28/26 9:20 AM, Jan Beulich wrote:
> This can be easily done in hypercall-defs.c, thus avoiding the need to
> dive into xsm/ when building Xen, just to add code which does what is done
> for an absent hypercall handler anyway (returning -ENOSYS).
> 
> Signed-off-by: Jan Beulich <[email protected]>
> 
> --- a/xen/Makefile
> +++ b/xen/Makefile
> @@ -458,7 +458,7 @@ CFLAGS += -I$(objtree)/arch/$(SRCARCH)/i
>   ALL_OBJS-y                := common/built_in.o
>   ALL_OBJS-y                += drivers/built_in.o
>   ALL_OBJS-y                += lib/built_in.o
> -ALL_OBJS-y                += xsm/built_in.o
> +ALL_OBJS-$(CONFIG_XSM)    += xsm/built_in.o
>   ALL_OBJS-y                += arch/$(SRCARCH)/built_in.o
>   ALL_OBJS-$(CONFIG_CRYPTO) += crypto/built_in.o
>   
> --- a/xen/include/hypercall-defs.c
> +++ b/xen/include/hypercall-defs.c
> @@ -119,7 +119,9 @@ prefix: do PREFIX_compat
>   xen_version(int cmd, void *arg)
>   vcpu_op(int cmd, unsigned int vcpuid, void *arg)
>   sched_op(int cmd, void *arg)
> +#ifdef CONFIG_XSM
>   xsm_op(void *op)
> +#endif
>   callback_op(int cmd, const void *arg)
>   #ifdef CONFIG_ARGO
>   argo_op(unsigned int cmd, void *arg1, void *arg2, unsigned long arg3, unsigned long arg4)
> @@ -264,7 +266,9 @@ set_segment_base                   do:2
>   #ifdef CONFIG_PV
>   mmuext_op                          compat:2 do:2     compat   do       -
>   #endif
> +#ifdef CONFIG_XSM
>   xsm_op                             compat   do       compat   do       do
> +#endif
>   nmi_op                             compat   do       -        -        -
>   sched_op                           compat   do       compat   do       do
>   callback_op                        compat   do       -        -        -
> --- a/xen/include/xsm/dummy.h
> +++ b/xen/include/xsm/dummy.h
> @@ -437,6 +437,8 @@ static XSM_INLINE int xsm_hypfs_op(XSM_D
>   }
>   #endif
>   
> +#ifdef CONFIG_XSM
> +
>   static XSM_INLINE long xsm_do_xsm_op(XEN_GUEST_HANDLE_PARAM(void) op)
>   {
>       return -ENOSYS;
> @@ -449,6 +451,8 @@ static XSM_INLINE int xsm_do_compat_op(X
>   }
>   #endif
>   
> +#endif /* CONFIG_XSM */
> +
>   static XSM_INLINE char *xsm_show_irq_sid(int irq)
>   {
>       return NULL;
> --- a/xen/xsm/Makefile
> +++ b/xen/xsm/Makefile
> @@ -1,6 +1,6 @@
>   obj-y += xsm_core.o
> -obj-$(CONFIG_XSM) += xsm_policy.o
> -obj-$(CONFIG_XSM) += dummy.o
> +obj-y += xsm_policy.o
> +obj-y += dummy.o
>   obj-$(CONFIG_XSM_SILO) += silo.o
>   
>   obj-$(CONFIG_XSM_FLASK) += flask/
> --- a/xen/xsm/xsm_core.c
> +++ b/xen/xsm/xsm_core.c
> @@ -18,8 +18,6 @@
>   #include <xen/hypercall.h>
>   #include <xsm/xsm.h>
>   
> -#ifdef CONFIG_XSM
> -
>   #ifdef CONFIG_MULTIBOOT
>   #include <asm/bootinfo.h>
>   #include <asm/setup.h>
> @@ -216,8 +214,6 @@ bool __init has_xsm_magic(paddr_t start)
>   }
>   #endif
>   
> -#endif
> -
>   long do_xsm_op(XEN_GUEST_HANDLE_PARAM(void) op)
>   {
>       return xsm_do_xsm_op(op);
> 

Acked-by: Daniel P. Smith <[email protected]>