Re: [PATCH 01 of 10 [RFC]] libxc: Generalize xenctl_cpumap to just xenctl_map

[George Dunlap <george.dunlap@eu.citrix.com>]

On 11/04/12 14:17, Dario Faggioli wrote:
> In preparation for adding an xc_nodemap_t and its related
> hadling logic. Just add one indirection layer, and try to
> retain the interface as much as possible (although some
> small bits here and there have been affected).
This patch is fine with me on the whole (one comment below), but in this 
kind of a patch I think you need to include exactly what it is patch 
does.  I.e.:

1. Replace xenctl_cpumap with xenctl_map
2. Implement bitmap_to_xenctl_map and the reverse
3. Re-implement cpumask_to_xenctl_map with bitmap_to_xenctl_map and vice 
versa.
4. Other than #3, no functional changes.
>
> Signed-off-by: Dario Faggioli<dario.faggioli@citrix.eu.com>
>
> diff --git a/tools/libxc/xc_cpupool.c b/tools/libxc/xc_cpupool.c
> --- a/tools/libxc/xc_cpupool.c
> +++ b/tools/libxc/xc_cpupool.c
> @@ -90,7 +90,7 @@ xc_cpupoolinfo_t *xc_cpupool_getinfo(xc_
>       sysctl.u.cpupool_op.op = XEN_SYSCTL_CPUPOOL_OP_INFO;
>       sysctl.u.cpupool_op.cpupool_id = poolid;
>       set_xen_guest_handle(sysctl.u.cpupool_op.cpumap.bitmap, local);
> -    sysctl.u.cpupool_op.cpumap.nr_cpus = local_size * 8;
> +    sysctl.u.cpupool_op.cpumap.nr_elems = local_size * 8;
>
>       err = do_sysctl_save(xch,&sysctl);
>
> @@ -184,7 +184,7 @@ xc_cpumap_t xc_cpupool_freeinfo(xc_inter
>       sysctl.cmd = XEN_SYSCTL_cpupool_op;
>       sysctl.u.cpupool_op.op = XEN_SYSCTL_CPUPOOL_OP_FREEINFO;
>       set_xen_guest_handle(sysctl.u.cpupool_op.cpumap.bitmap, local);
> -    sysctl.u.cpupool_op.cpumap.nr_cpus = mapsize * 8;
> +    sysctl.u.cpupool_op.cpumap.nr_elems = mapsize * 8;
>
>       err = do_sysctl_save(xch,&sysctl);
>
> diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
> --- a/tools/libxc/xc_domain.c
> +++ b/tools/libxc/xc_domain.c
> @@ -142,7 +142,7 @@ int xc_vcpu_setaffinity(xc_interface *xc
>
>       set_xen_guest_handle(domctl.u.vcpuaffinity.cpumap.bitmap, local);
>
> -    domctl.u.vcpuaffinity.cpumap.nr_cpus = cpusize * 8;
> +    domctl.u.vcpuaffinity.cpumap.nr_elems = cpusize * 8;
>
>       ret = do_domctl(xch,&domctl);
>
> @@ -182,7 +182,7 @@ int xc_vcpu_getaffinity(xc_interface *xc
>       domctl.u.vcpuaffinity.vcpu = vcpu;
>
>       set_xen_guest_handle(domctl.u.vcpuaffinity.cpumap.bitmap, local);
> -    domctl.u.vcpuaffinity.cpumap.nr_cpus = cpusize * 8;
> +    domctl.u.vcpuaffinity.cpumap.nr_elems = cpusize * 8;
>
>       ret = do_domctl(xch,&domctl);
>
> diff --git a/tools/libxc/xc_tbuf.c b/tools/libxc/xc_tbuf.c
> --- a/tools/libxc/xc_tbuf.c
> +++ b/tools/libxc/xc_tbuf.c
> @@ -134,7 +134,7 @@ int xc_tbuf_set_cpu_mask(xc_interface *x
>       bitmap_64_to_byte(bytemap,&mask64, sizeof (mask64) * 8);
>
>       set_xen_guest_handle(sysctl.u.tbuf_op.cpu_mask.bitmap, bytemap);
> -    sysctl.u.tbuf_op.cpu_mask.nr_cpus = sizeof(bytemap) * 8;
> +    sysctl.u.tbuf_op.cpu_mask.nr_elems = sizeof(bytemap) * 8;
>
>       ret = do_sysctl(xch,&sysctl);
>
> diff --git a/xen/arch/x86/platform_hypercall.c b/xen/arch/x86/platform_hypercall.c
> --- a/xen/arch/x86/platform_hypercall.c
> +++ b/xen/arch/x86/platform_hypercall.c
> @@ -365,7 +365,7 @@ ret_t do_platform_op(XEN_GUEST_HANDLE(xe
>       {
>           uint32_t cpu;
>           uint64_t idletime, now = NOW();
> -        struct xenctl_cpumap ctlmap;
> +        struct xenctl_map ctlmap;
>           cpumask_var_t cpumap;
>           XEN_GUEST_HANDLE(uint8) cpumap_bitmap;
>           XEN_GUEST_HANDLE(uint64) idletimes;
> @@ -378,7 +378,7 @@ ret_t do_platform_op(XEN_GUEST_HANDLE(xe
>           if ( cpufreq_controller != FREQCTL_dom0_kernel )
>               break;
>
> -        ctlmap.nr_cpus  = op->u.getidletime.cpumap_nr_cpus;
> +        ctlmap.nr_elems  = op->u.getidletime.cpumap_nr_cpus;
>           guest_from_compat_handle(cpumap_bitmap,
>                                    op->u.getidletime.cpumap_bitmap);
>           ctlmap.bitmap.p = cpumap_bitmap.p; /* handle ->  handle_64 conversion */
> diff --git a/xen/common/domctl.c b/xen/common/domctl.c
> --- a/xen/common/domctl.c
> +++ b/xen/common/domctl.c
> @@ -31,28 +31,29 @@
>   static DEFINE_SPINLOCK(domctl_lock);
>   DEFINE_SPINLOCK(vcpu_alloc_lock);
>
> -int cpumask_to_xenctl_cpumap(
> -    struct xenctl_cpumap *xenctl_cpumap, const cpumask_t *cpumask)
> +int bitmap_to_xenctl_map(struct xenctl_map *xenctl_map,
> +                         const unsigned long *bitmap,
> +                         unsigned int nbits)
>   {
>       unsigned int guest_bytes, copy_bytes, i;
>       uint8_t zero = 0;
>       int err = 0;
> -    uint8_t *bytemap = xmalloc_array(uint8_t, (nr_cpu_ids + 7) / 8);
> +    uint8_t *bytemap = xmalloc_array(uint8_t, (nbits + 7) / 8);
>
>       if ( !bytemap )
>           return -ENOMEM;
>
> -    guest_bytes = (xenctl_cpumap->nr_cpus + 7) / 8;
> -    copy_bytes  = min_t(unsigned int, guest_bytes, (nr_cpu_ids + 7) / 8);
> +    guest_bytes = (xenctl_map->nr_elems + 7) / 8;
> +    copy_bytes  = min_t(unsigned int, guest_bytes, (nbits + 7) / 8);
>
> -    bitmap_long_to_byte(bytemap, cpumask_bits(cpumask), nr_cpu_ids);
> +    bitmap_long_to_byte(bytemap, bitmap, nbits);
>
>       if ( copy_bytes != 0 )
> -        if ( copy_to_guest(xenctl_cpumap->bitmap, bytemap, copy_bytes) )
> +        if ( copy_to_guest(xenctl_map->bitmap, bytemap, copy_bytes) )
>               err = -EFAULT;
>
>       for ( i = copy_bytes; !err&&  i<  guest_bytes; i++ )
> -        if ( copy_to_guest_offset(xenctl_cpumap->bitmap, i,&zero, 1) )
> +        if ( copy_to_guest_offset(xenctl_map->bitmap, i,&zero, 1) )
>               err = -EFAULT;
>
>       xfree(bytemap);
> @@ -60,36 +61,58 @@ int cpumask_to_xenctl_cpumap(
>       return err;
>   }
>
> -int xenctl_cpumap_to_cpumask(
> -    cpumask_var_t *cpumask, const struct xenctl_cpumap *xenctl_cpumap)
> +int xenctl_map_to_bitmap(unsigned long *bitmap,
> +                         const struct xenctl_map *xenctl_map,
> +                         unsigned int nbits)
>   {
>       unsigned int guest_bytes, copy_bytes;
>       int err = 0;
> -    uint8_t *bytemap = xzalloc_array(uint8_t, (nr_cpu_ids + 7) / 8);
> +    uint8_t *bytemap = xzalloc_array(uint8_t, (nbits + 7) / 8);
>
>       if ( !bytemap )
>           return -ENOMEM;
>
> -    guest_bytes = (xenctl_cpumap->nr_cpus + 7) / 8;
> -    copy_bytes  = min_t(unsigned int, guest_bytes, (nr_cpu_ids + 7) / 8);
> +    guest_bytes = (xenctl_map->nr_elems + 7) / 8;
> +    copy_bytes  = min_t(unsigned int, guest_bytes, (nbits + 7) / 8);
>
>       if ( copy_bytes != 0 )
>       {
> -        if ( copy_from_guest(bytemap, xenctl_cpumap->bitmap, copy_bytes) )
> +        if ( copy_from_guest(bytemap, xenctl_map->bitmap, copy_bytes) )
>               err = -EFAULT;
> -        if ( (xenctl_cpumap->nr_cpus&  7)&&  (guest_bytes<= sizeof(bytemap)) )
> -            bytemap[guest_bytes-1]&= ~(0xff<<  (xenctl_cpumap->nr_cpus&  7));
> +        if ( (xenctl_map->nr_elems&  7)&&  (guest_bytes<= sizeof(bytemap)) )
> +            bytemap[guest_bytes-1]&= ~(0xff<<  (xenctl_map->nr_elems&  7));
>       }
>
> -    if ( err )
> -        /* nothing */;
> -    else if ( alloc_cpumask_var(cpumask) )
> -        bitmap_byte_to_long(cpumask_bits(*cpumask), bytemap, nr_cpu_ids);
> +    if ( !err )
> +        bitmap_byte_to_long(bitmap, bytemap, nbits);
> +
> +    xfree(bytemap);
> +
> +    return err;
> +}
> +
> +int cpumask_to_xenctl_cpumap(struct xenctl_map *xenctl_cpumap,
> +                             const cpumask_t *cpumask)
> +{
> +    return bitmap_to_xenctl_map(xenctl_cpumap, cpumask_bits(cpumask),
> +                                nr_cpu_ids);
> +}
> +
> +int xenctl_cpumap_to_cpumask(cpumask_var_t *cpumask,
> +                             const struct xenctl_map *xenctl_cpumap)
> +{
> +    int err = 0;
> +
> +    if ( alloc_cpumask_var(cpumask) ) {
> +        err = xenctl_map_to_bitmap(cpumask_bits(*cpumask), xenctl_cpumap,
> +                                   nr_cpu_ids);
> +        /* In case of error, cleanup is up to us, as the caller won't care! */
> +        if ( err )
> +            free_cpumask_var(*cpumask);
> +    }
>       else
>           err = -ENOMEM;
>
> -    xfree(bytemap);
> -
>       return err;
>   }
>
> diff --git a/xen/include/public/arch-x86/xen-mca.h b/xen/include/public/arch-x86/xen-mca.h
> --- a/xen/include/public/arch-x86/xen-mca.h
> +++ b/xen/include/public/arch-x86/xen-mca.h
> @@ -414,7 +414,7 @@ struct xen_mc_mceinject {
>
>   struct xen_mc_inject_v2 {
>   	uint32_t flags;
> -	struct xenctl_cpumap cpumap;
> +	struct xenctl_map cpumap;
>   };
>   #endif
>
> diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
> --- a/xen/include/public/domctl.h
> +++ b/xen/include/public/domctl.h
> @@ -283,7 +283,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_getvc
>   /* XEN_DOMCTL_getvcpuaffinity */
>   struct xen_domctl_vcpuaffinity {
>       uint32_t  vcpu;              /* IN */
> -    struct xenctl_cpumap cpumap; /* IN/OUT */
> +    struct xenctl_map cpumap;    /* IN/OUT */
>   };
>   typedef struct xen_domctl_vcpuaffinity xen_domctl_vcpuaffinity_t;
>   DEFINE_XEN_GUEST_HANDLE(xen_domctl_vcpuaffinity_t);
> diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
> --- a/xen/include/public/sysctl.h
> +++ b/xen/include/public/sysctl.h
> @@ -71,8 +71,8 @@ struct xen_sysctl_tbuf_op {
>   #define XEN_SYSCTL_TBUFOP_disable      5
>       uint32_t cmd;
>       /* IN/OUT variables */
> -    struct xenctl_cpumap cpu_mask;
> -    uint32_t             evt_mask;
> +    struct xenctl_map cpu_mask;
> +    uint32_t          evt_mask;
>       /* OUT variables */
>       uint64_aligned_t buffer_mfn;
>       uint32_t size;  /* Also an IN variable! */
> @@ -531,7 +531,7 @@ struct xen_sysctl_cpupool_op {
>       uint32_t domid;       /* IN: M              */
>       uint32_t cpu;         /* IN: AR             */
>       uint32_t n_dom;       /*            OUT: I  */
> -    struct xenctl_cpumap cpumap; /*     OUT: IF */
> +    struct xenctl_map cpumap;    /*     OUT: IF */
>   };
>   typedef struct xen_sysctl_cpupool_op xen_sysctl_cpupool_op_t;
>   DEFINE_XEN_GUEST_HANDLE(xen_sysctl_cpupool_op_t);
> diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
> --- a/xen/include/public/xen.h
> +++ b/xen/include/public/xen.h
> @@ -822,9 +822,9 @@ typedef uint8_t xen_domain_handle_t[16];
>   #endif
>
>   #ifndef __ASSEMBLY__
> -struct xenctl_cpumap {
> +struct xenctl_map {
>       XEN_GUEST_HANDLE_64(uint8) bitmap;
> -    uint32_t nr_cpus;
> +    uint32_t nr_elems;
>   };
>   #endif
>
> diff --git a/xen/include/xen/cpumask.h b/xen/include/xen/cpumask.h
> --- a/xen/include/xen/cpumask.h
> +++ b/xen/include/xen/cpumask.h
> @@ -424,8 +424,8 @@ extern cpumask_t cpu_present_map;
>   #define for_each_present_cpu(cpu)  for_each_cpu(cpu,&cpu_present_map)
>
>   /* Copy to/from cpumap provided by control tools. */
> -struct xenctl_cpumap;
> -int cpumask_to_xenctl_cpumap(struct xenctl_cpumap *, const cpumask_t *);
> -int xenctl_cpumap_to_cpumask(cpumask_var_t *, const struct xenctl_cpumap *);
> +struct xenctl_map;
> +int cpumask_to_xenctl_cpumap(struct xenctl_map *, const cpumask_t *);
> +int xenctl_cpumap_to_cpumask(cpumask_var_t *, const struct xenctl_map *);
You should probably s/cpumap/map/; in the function names as well.
>
>   #endif /* __XEN_CPUMASK_H */
> diff --git a/xen/include/xlat.lst b/xen/include/xlat.lst
> --- a/xen/include/xlat.lst
> +++ b/xen/include/xlat.lst
> @@ -2,7 +2,7 @@
>   # ! - needs translation
>   # ? - needs checking
>   ?	dom0_vga_console_info		xen.h
> -?	xenctl_cpumap			xen.h
> +?	xenctl_map			xen.h
>   ?	mmu_update			xen.h
>   !	mmuext_op			xen.h
>   !	start_info			xen.h