Re: [XEN PATCH v2] amd/iommu: clean up unused guest iommu related functions

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

On 2024-03-15 14:31, Jan Beulich wrote:
> On 15.03.2024 12:16, Nicola Vetrini wrote:
> > Delete unused functions from 'iommu_guest.c'.
> >
> > The 'cmd' parameter of amd_iommu_send_guest_cmd is passed
> > to a function that expects arrays of size 4, therefore
> > specifying explicitly the size also in amd_iommu_send_guest_cmd
> > allows not to accidentally pass a bigger array.
> >
> > No functional change.
> >
> > Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
> > ---
> > All current users of amd_iommu_send_guest pass an array of size 4,
> > hence this is fixing a potential issue noticed by the analyzer for 
> > MISRA C
> > Rule 17.5, not an actual bug.
> >
> > guest_iommu_add_ptr_log has still one caller, but even that seems
> > suspicious. I left it in and uniformed its parameter type at the
> > moment, so that whether it should be kept can be sorted out later.
> > If that caller indeed should be removed as well, then
> > no function in the file is actually reachable as far as I can tell.
> Afaict this wants removing too.
>
> But what I'm more puzzled by: You remove all callers of
> amd_iommu_send_guest_cmd(), yet still ...
>
> > --- a/xen/drivers/passthrough/amd/iommu.h
> > +++ b/xen/drivers/passthrough/amd/iommu.h
> > @@ -346,12 +346,8 @@ void cf_check amd_iommu_crash_shutdown(void);
> >
> >  /* guest iommu support */
> >  #ifdef CONFIG_HVM
> > -void amd_iommu_send_guest_cmd(struct amd_iommu *iommu, u32 cmd[]);
> > -void guest_iommu_add_ppr_log(struct domain *d, u32 entry[]);
> > -void guest_iommu_add_event_log(struct domain *d, u32 entry[]);
> > -int guest_iommu_init(struct domain* d);
> > -void guest_iommu_destroy(struct domain *d);
> > -int guest_iommu_set_base(struct domain *d, uint64_t base);
> > +void amd_iommu_send_guest_cmd(struct amd_iommu *iommu, uint32_t 
> > cmd[4]);
> ... retain the function.
>
> Jan
Right, I forgot to remove it.
Thanks,

--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)