Re: [Xen-devel] [PATCH v2] introduce grant copy for user land

[David Vrabel <david.vrabel@xxxxxxxxxx>]

On 02/12/14 16:13, Thanos Makatos wrote:
>  
> +struct gntdev_grant_copy_segment {
> +
> +     union {
> +             /* copy from (to) self to (from) guest */
> +             struct {
> +                     /*
> +                      * source address and length
> +                      */
> +                     struct iovec iov;
> +
> +                     /* the granted page */
> +                     uint32_t ref;
> +
> +                     /* offset in the granted page */
> +                     uint16_t offset;
> +             } self;
> +
> +             /* copy from guest to guest */
> +             struct {
> +                     uint16_t len;
> +
> +                     struct {
> +                             /* the granted page */
> +                             uint32_t ref;
> +
> +                             /* offset in the granted page */
> +                             uint16_t offset;
> +                     } src, dst;
> +             } g2g;
> +     };
> +
> +     /* grant copy result (GNTST_XXX) */
> +     int16_t status;
> +};

I asked for this ioctl to mirror the hypercall.

Which looks like:

struct gnttab_copy {
        /* IN parameters. */
        struct {
                union {
                        grant_ref_t ref;
                        xen_pfn_t   gmfn;
                } u;
                domid_t  domid;
                uint16_t offset;
        } source, dest;
        uint16_t      len;
        uint16_t      flags;          /* GNTCOPY_* */
        /* OUT parameters. */
        int16_t       status;
};

i.e., each operation specifies the domid of the source and destination
and whether it includes a ref or a virtual address.

David

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