Re: [PATCH v6 4/9] xen/asm-generic: introduce stub header monitor.h

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 20/12/2023 2:08 pm, Oleksii Kurochko wrote:
> diff --git a/xen/include/asm-generic/monitor.h 
> b/xen/include/asm-generic/monitor.h
> new file mode 100644
> index 0000000000..74e4870cd7
> --- /dev/null
> +++ b/xen/include/asm-generic/monitor.h
> @@ -0,0 +1,57 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * include/asm-generic/monitor.h
> + *
> + * Arch-specific monitor_op domctl handler.
> + *
> + * Copyright (c) 2015 Tamas K Lengyel (tamas@xxxxxxxxxxxxx)
> + * Copyright (c) 2016, Bitdefender S.R.L.
> + *
> + */
> +
> +#ifndef __ASM_GENERIC_MONITOR_H__
> +#define __ASM_GENERIC_MONITOR_H__
> +
> +#include <xen/errno.h>
> +
> +struct domain;
> +struct xen_domctl_monitor_op;
> +
> +static inline
> +void arch_monitor_allow_userspace(struct domain *d, bool allow_userspace)
> +{
> +}
> +
> +static inline
> +int arch_monitor_domctl_op(struct domain *d, struct xen_domctl_monitor_op 
> *mop)
> +{
> +    /* No arch-specific monitor ops on GENERIC. */
> +    return -EOPNOTSUPP;
> +}
> +
> +int arch_monitor_domctl_event(struct domain *d,
> +                              struct xen_domctl_monitor_op *mop);

Turn this into a static inline like the others, and you can delete:

arch/ppc/stubs.c:100

int arch_monitor_domctl_event(struct domain *d,
                              struct xen_domctl_monitor_op *mop)
{
    BUG_ON("unimplemented");
}

because new architectures shouldn't have to stub one random piece of a
subsystem when using the generic "nothing special" header.

Given the filtering for arch_monitor_domctl_op(), this one probably
wants to be ASSERT_UNREACHABLE(); return 0.

~Andrew