Re: [Xen-devel] [PATCH 5/5] kexec/xen: directly load images images into Xen

[Daniel Kiper <daniel.kiper@xxxxxxxxxx>]

On Mon, Apr 08, 2013 at 08:06:54PM +0100, David Vrabel wrote:
> From: David Vrabel <david.vrabel@xxxxxxxxxx>
>
> Xen 4.3 has an improvided kexec hypercall ABI that allows images to be
> loaded and executed without any kernel involvement.  Use the API
> provided by libxc to load images when running in a Xen guest.
>
> Support for loading images via the kexec_load syscall in non-upstream
> ("classic") Xen kernels is no longer supported.
>
> Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>

[...]

> diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c

[...]

> +int xen_kexec_load(uint64_t entry,
> +                uint32_t nr_segments, struct kexec_segment *segments,
> +                uint64_t kexec_flags)
> +{
> +     xc_interface *xch;
> +     xc_hypercall_buffer_array_t *array = NULL;
> +     uint8_t type;
> +     uint8_t arch;
> +     xen_kexec_segment_t *xen_segs;
> +     int s;
> +     int ret = -1;
> +
> +     xch = xc_interface_open(NULL, NULL, 0);
> +     if (!xch)
> +             return -1;
> +
> +     xen_segs = calloc(nr_segments, sizeof(*xen_segs));
> +     if (!xen_segs)
> +             goto out;
> +
> +     array = xc_hypercall_buffer_array_create(xch, nr_segments);
> +     if (array == NULL)
> +             goto out;
> +
> +     for (s = 0; s < nr_segments; s++) {
> +             DECLARE_HYPERCALL_BUFFER(void, seg_buf);
> +
> +             seg_buf = xc_hypercall_buffer_array_alloc(xch, array, s,
> +                                                       seg_buf, 
> segments[s].bufsz);
> +             if (seg_buf == NULL)
> +                     goto out;
> +             memcpy(seg_buf, segments[s].buf, segments[s].bufsz);
> +
> +             set_xen_guest_handle(xen_segs[s].buf, seg_buf);
> +             xen_segs[s].buf_size = segments[s].bufsz;
> +             xen_segs[s].dest_maddr = (uint64_t)segments[s].mem;
> +             xen_segs[s].dest_size = segments[s].memsz;
> +     }
> +
> +     type = kexec_flags & KEXEC_TYPE_CRASH;
> +     arch = (kexec_flags >> 16) & 0xffff;

arch = (kexec_flags & KEXEC_ARCH_MASK) >> 16;

Daniel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel