"Dr. David Alan Gilbert (git)" <[email protected]> wrote:
> From: "Dr. David Alan Gilbert" <[email protected]>
>
> Signed-off-by: Dr. David Alan Gilbert <[email protected]>
> Reviewed-by: David Gibson <[email protected]>
> Reviewed-by: Amit Shah <[email protected]>
> +/*
> + * At the end of migration, undo the effects of init_range
> + * opaque should be the MIS.
> + */
> +static int cleanup_range(const char *block_name, void *host_addr,
> + ram_addr_t offset, ram_addr_t length, void *opaque)
> +{
> + MigrationIncomingState *mis = opaque;
> + struct uffdio_range range_struct;
> + trace_postcopy_cleanup_range(block_name, host_addr, offset, length);
> +
> + /*
> + * We turned off hugepage for the precopy stage with postcopy enabled
> + * we can turn it back on now.
> + */
> +#ifdef MADV_HUGEPAGE
> + if (madvise(host_addr, length, MADV_HUGEPAGE)) {
> + error_report("%s HUGEPAGE: %s", __func__, strerror(errno));
> + return -1;
> + }
> +#endif
this should be the same than:
qemu_madvise(host_addr, lenght, QEMU_MADV_HUGEPAGE);
Only problem I can see, is that there is no way to differentiate that
madvise() has given one error or that MADV_HUGEPAGE is not defined.
If we really want that:
if (QEMU_MADV_HUGEPAGE != QEM_MADV_INVALID) {
if (qemu_madvise(host_addr, length, QEMU_MADV_HUGEPAGE)) {
error_report("%s HUGEPAGE: %s", __func__, strerror(errno));
return -1;
}
But I am not sure if we want it.
> +
> + /*
> + * We can also turn off userfault now since we should have all the
> + * pages. It can be useful to leave it on to debug postcopy
> + * if you're not sure it's always getting every page.
> + */
> + range_struct.start = (uintptr_t)host_addr;
> + range_struct.len = length;
> +
> + if (ioctl(mis->userfault_fd, UFFDIO_UNREGISTER, &range_struct)) {
> + error_report("%s: userfault unregister %s", __func__,
> strerror(errno));
> +
> + return -1;
> + }
> +
> + return 0;
> +}
I still think that exposing the userfault API all around is a bad idea,
that it would be easier to just export:
qemu_userfault_register_range(addr, lenght);
qemu_userfault_unregister_range(addr, lenght);
And hide the details on a header file.
Later, Juan.
