Re: [Patch v6 11/13] tools/libxc: x86 HVM restore code

[Wen Congyang <ghostwcy@gmail.com>]

At 2014/7/8 1:38, Andrew Cooper Wrote:
> Restore the x86 HVM specific parts of a domain.  This is the HVM_CONTEXT and
> HVM_PARAMS records.
>
> There is no need for any page localisation.
>
> This also includes writing the trailing qemu save record to a file because
> this is what libxc currently does.  This is intended to be moved into libxl
> proper in the future.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> ---
>   tools/libxc/saverestore/common.h          |    1 +
>   tools/libxc/saverestore/restore_x86_hvm.c |  336 +++++++++++++++++++++++++++++
>   2 files changed, 337 insertions(+)
>   create mode 100644 tools/libxc/saverestore/restore_x86_hvm.c
>
> diff --git a/tools/libxc/saverestore/common.h b/tools/libxc/saverestore/common.h
> index 8d125f9..4894cac 100644
> --- a/tools/libxc/saverestore/common.h
> +++ b/tools/libxc/saverestore/common.h
> @@ -241,6 +241,7 @@ extern struct xc_sr_save_ops save_ops_x86_pv;
>   extern struct xc_sr_save_ops save_ops_x86_hvm;
>
>   extern struct xc_sr_restore_ops restore_ops_x86_pv;
> +extern struct xc_sr_restore_ops restore_ops_x86_hvm;
>
>   struct xc_sr_record
>   {
> diff --git a/tools/libxc/saverestore/restore_x86_hvm.c b/tools/libxc/saverestore/restore_x86_hvm.c
> new file mode 100644
> index 0000000..0004dee
> --- /dev/null
> +++ b/tools/libxc/saverestore/restore_x86_hvm.c
> @@ -0,0 +1,336 @@
> +#include <assert.h>
> +#include <arpa/inet.h>
> +
> +#include "common_x86.h"
> +
> +/* TODO: remove */
> +static int handle_toolstack(struct xc_sr_context *ctx, struct xc_sr_record *rec)
> +{
> +    xc_interface *xch = ctx->xch;
> +    int rc;
> +
> +    if ( !ctx->restore.callbacks || !ctx->restore.callbacks->toolstack_restore )
> +        return 0;
> +
> +    rc = ctx->restore.callbacks->toolstack_restore(ctx->domid, rec->data, rec->length,
> +                                                   ctx->restore.callbacks->data);
> +    if ( rc < 0 )
> +        PERROR("restoring toolstack");
> +    return rc;
> +}
> +
> +/*
> + * Process an HVM_CONTEXT record from the stream.
> + */
> +static int handle_hvm_context(struct xc_sr_context *ctx, struct xc_sr_record *rec)
> +{
> +    xc_interface *xch = ctx->xch;
> +    int rc;
> +
> +    rc = xc_domain_hvm_setcontext(xch, ctx->domid, rec->data, rec->length);
> +    if ( rc < 0 )
> +        PERROR("Unable to restore HVM context");
> +    return rc;
> +}
> +
> +/*
> + * Process an HVM_PARAMS record from the stream.
> + */
> +static int handle_hvm_params(struct xc_sr_context *ctx, struct xc_sr_record *rec)
> +{
> +    xc_interface *xch = ctx->xch;
> +    struct xc_sr_rec_hvm_params *hdr = rec->data;
> +    struct xc_sr_rec_hvm_params_entry *entry = hdr->param;
> +    unsigned int i;
> +    int rc;
> +
> +    if ( rec->length < sizeof(*hdr)
> +         || rec->length < sizeof(*hdr) + hdr->count * sizeof(*entry) )
> +    {
> +        ERROR("hvm_params record is too short");
> +        return -1;
> +    }
> +
> +    for ( i = 0; i < hdr->count; i++, entry++ )
> +    {
> +        switch ( entry->index )
> +        {
> +        case HVM_PARAM_CONSOLE_PFN:
> +            ctx->restore.console_mfn = entry->value;
> +            xc_clear_domain_page(xch, ctx->domid, entry->value);
> +            break;
> +        case HVM_PARAM_STORE_PFN:
> +            ctx->restore.xenstore_mfn = entry->value;
> +            xc_clear_domain_page(xch, ctx->domid, entry->value);
> +            break;
> +        case HVM_PARAM_IOREQ_PFN:
> +        case HVM_PARAM_BUFIOREQ_PFN:
> +            xc_clear_domain_page(xch, ctx->domid, entry->value);

ioreq page may contain pending i/o request, so I think we should not clear
them.

Thanks
Wen Congyang

> +            break;
> +        }
> +
> +        rc = xc_set_hvm_param(xch, ctx->domid, entry->index, entry->value);
> +        if ( rc < 0 )
> +        {
> +            PERROR("set HVM param %"PRId64" = 0x%016"PRIx64,
> +                   entry->index, entry->value);
> +            return rc;
> +        }
> +    }
> +    return 0;
> +}
> +