Re: [PATCH v7 7/9] common/domain: add a domain context record for shared_info...

[Jan Beulich <jbeulich@xxxxxxxx>]

On 18.08.2020 12:30, Paul Durrant wrote:
> v7:
>  - Only restore vcpu_info and arch sub-structures for PV domains, to match
>    processing of SHARED_INFO in xc_sr_restore_x86_pv.c

Since you point out this original logic, ...

> +static int load_shared_info(struct domain *d, struct domain_context *c)
> +{
> +    struct domain_shared_info_context ctxt;
> +    size_t hdr_size = offsetof(typeof(ctxt), buffer);
> +    unsigned int i;
> +    int rc;
> +
> +    rc = DOMAIN_LOAD_BEGIN(SHARED_INFO, c, &i);
> +    if ( rc )
> +        return rc;
> +
> +    if ( i ) /* expect only a single instance */
> +        return -ENXIO;
> +
> +    rc = domain_load_data(c, &ctxt, hdr_size);
> +    if ( rc )
> +        return rc;
> +
> +    if ( ctxt.buffer_size > sizeof(shared_info_t) ||
> +         (ctxt.flags & ~DOMAIN_SAVE_32BIT_SHINFO) )
> +        return -EINVAL;
> +
> +    if ( ctxt.flags & DOMAIN_SAVE_32BIT_SHINFO )
> +    {
> +#ifdef CONFIG_COMPAT
> +        has_32bit_shinfo(d) = true;
> +#else
> +        return -EINVAL;
> +#endif
> +    }
> +
> +    if ( is_pv_domain(d) )
> +    {
> +        shared_info_t *shinfo = xmalloc(shared_info_t);
> +
> +        rc = domain_load_data(c, shinfo, sizeof(*shinfo));
> +        if ( rc )
> +        {
> +            xfree(shinfo);
> +            return rc;
> +        }
> +
> +#ifdef CONFIG_COMPAT
> +        if ( has_32bit_shinfo(d) )
> +        {
> +            memcpy(&d->shared_info->compat.vcpu_info,
> +                   &shinfo->compat.vcpu_info,
> +                   sizeof(d->shared_info->compat.vcpu_info));
> +            memcpy(&d->shared_info->compat.arch,
> +                   &shinfo->compat.arch,
> +                   sizeof(d->shared_info->compat.vcpu_info));
> +        }
> +        else
> +        {
> +            memcpy(&d->shared_info->native.vcpu_info,
> +                   &shinfo->native.vcpu_info,
> +                   sizeof(d->shared_info->native.vcpu_info));
> +            memcpy(&d->shared_info->native.arch,
> +                   &shinfo->native.arch,
> +                   sizeof(d->shared_info->native.arch));
> +        }
> +#else
> +        memcpy(&d->shared_info->vcpu_info,
> +               &shinfo->vcpu_info,
> +               sizeof(d->shared_info->vcpu_info));
> +        memcpy(&d->shared_info->arch,
> +               &shinfo->arch,
> +               sizeof(d->shared_info->shared));
> +#endif

... where does the rest of that logic (resetting of
arch.pfn_to_mfn_frame_list_list, evtchn_pending, evtchn_mask, and
evtchn_pending_sel) get done? Or why is it not needed anymore?

Jan