Re: [PATCH 2/2] domain: expose newly introduced hypercalls as XENFEAT

[Henry Wang <Henry.Wang@xxxxxxx>]

Hi Roger,

> On Oct 6, 2023, at 17:13, Roger Pau Monne <roger.pau@xxxxxxxxxx> wrote:
> 
> XENFEAT_runstate_phys_area is exposed to all architectures, while
> XENFEAT_vcpu_time_phys_area is currnelty only implemented for x86, and hence
> the feature flag is also only exposed on x86.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Release-acked-by: Henry Wang <Henry.Wang@xxxxxxx>

Kind regards,
Henry

> ---
> CHANGELOG.md                  | 2 ++
> xen/common/kernel.c           | 6 +++++-
> xen/include/public/features.h | 9 +++++++++
> 3 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/CHANGELOG.md b/CHANGELOG.md
> index e33cf4e1b113..41da710426f6 100644
> --- a/CHANGELOG.md
> +++ b/CHANGELOG.md
> @@ -31,6 +31,8 @@ The format is based on [Keep a 
> Changelog](https://keepachangelog.com/en/1.0.0/)
>  - Add Intel Hardware P-States (HWP) cpufreq driver.
>  - On Arm, experimental support for dynamic addition/removal of Xen device 
> tree
>    nodes using a device tree overlay binary (.dtbo).
> + - Introduce two new hypercalls to map the vCPU runstate and time areas by
> +   physical rather than linear addresses.
> 
> ### Removed
>  - On x86, the "pku" command line option has been removed.  It has never
> diff --git a/xen/common/kernel.c b/xen/common/kernel.c
> index 52aa28762782..b6302e44b34e 100644
> --- a/xen/common/kernel.c
> +++ b/xen/common/kernel.c
> @@ -607,7 +607,11 @@ long do_xen_version(int cmd, 
> XEN_GUEST_HANDLE_PARAM(void) arg)
>         switch ( fi.submap_idx )
>         {
>         case 0:
> -            fi.submap = (1U << XENFEAT_memory_op_vnode_supported);
> +            fi.submap = (1U << XENFEAT_memory_op_vnode_supported) |
> +#ifdef CONFIG_X86
> +                        (1U << XENFEAT_vcpu_time_phys_area) |
> +#endif
> +                        (1U << XENFEAT_runstate_phys_area);
>             if ( VM_ASSIST(d, pae_extended_cr3) )
>                 fi.submap |= (1U << XENFEAT_pae_pgdir_above_4gb);
>             if ( paging_mode_translate(d) )
> diff --git a/xen/include/public/features.h b/xen/include/public/features.h
> index d2a9175aae67..cffb2f14a562 100644
> --- a/xen/include/public/features.h
> +++ b/xen/include/public/features.h
> @@ -111,6 +111,15 @@
> #define XENFEAT_not_direct_mapped         16
> #define XENFEAT_direct_mapped             17
> 
> +/*
> + * Signal whether the hypervisor implements the following hypercalls:
> + *
> + * VCPUOP_register_runstate_phys_area
> + * VCPUOP_register_vcpu_time_phys_area
> + */
> +#define XENFEAT_runstate_phys_area  18
> +#define XENFEAT_vcpu_time_phys_area  19
> +
> #define XENFEAT_NR_SUBMAPS 1
> 
> #endif /* __XEN_PUBLIC_FEATURES_H__ */
> -- 
> 2.42.0
>