Re: [PATCH 1/3] arm/arm64/xen: use C inlines for privcmd_call

Julien Grall
2019-11-29T15:05:18Z

Hi,

On 27/11/2019 18:44, Pavel Tatashin wrote:
> diff --git a/arch/arm64/include/asm/xen/hypercall.h b/arch/arm64/include/asm/xen/hypercall.h
> index 3522cbaed316..1a74fb28607f 100644
> --- a/arch/arm64/include/asm/xen/hypercall.h
> +++ b/arch/arm64/include/asm/xen/hypercall.h
> @@ -1 +1,29 @@
> +#ifndef _ASM_ARM64_XEN_HYPERCALL_H
> +#define _ASM_ARM64_XEN_HYPERCALL_H
> #include <xen/arm/hypercall.h>
> +#include <linux/uaccess.h>
> +
> +static inline long privcmd_call(unsigned int call, unsigned long a1,
> + unsigned long a2, unsigned long a3,
> + unsigned long a4, unsigned long a5)

I realize that privcmd_call is the only hypercall using Software PAN at
the moment. However, dm_op needs the same as hypercall will be issued
from userspace as well.

So I was wondering whether we should create a generic function (e.g.
do_xen_hypercall() or do_xen_user_hypercall()) to cover the two hypercalls?

> diff --git a/include/xen/arm/hypercall.h b/include/xen/arm/hypercall.h
> index b40485e54d80..624c8ad7e42a 100644
> --- a/include/xen/arm/hypercall.h
> +++ b/include/xen/arm/hypercall.h
> @@ -30,8 +30,8 @@
> * IN THE SOFTWARE.
> */
>
> -#ifndef _ASM_ARM_XEN_HYPERCALL_H
> -#define _ASM_ARM_XEN_HYPERCALL_H
> +#ifndef _ARM_XEN_HYPERCALL_H
> +#define _ARM_XEN_HYPERCALL_H

This change feels a bit out of context. Could you split it in a separate
patch?

>
> #include <linux/bug.h>
>
> @@ -41,9 +41,9 @@
>
> struct xen_dm_op_buf;
>
> -long privcmd_call(unsigned call, unsigned long a1,
> - unsigned long a2, unsigned long a3,
> - unsigned long a4, unsigned long a5);
> +long arch_privcmd_call(unsigned int call, unsigned long a1,
> + unsigned long a2, unsigned long a3,
> + unsigned long a4, unsigned long a5);
> int HYPERVISOR_xen_version(int cmd, void *arg);
> int HYPERVISOR_console_io(int cmd, int count, char *str);
> int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count);
> @@ -88,4 +88,4 @@ MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
> BUG();
> }
>
> -#endif /* _ASM_ARM_XEN_HYPERCALL_H */
> +#endif /* _ARM_XEN_HYPERCALL_H */
>

Cheers,

--
Julien Grall