Re: [V7 PATCH 5/7] pvh: change xsm_add_to_physmap

[Daniel De Graaf <dgdegra@tycho.nsa.gov>]

On 12/16/2013 09:38 PM, Mukesh Rathor wrote:
> In preparation for the next patch, we update xsm_add_to_physmap to
> allow for checking of foreign domain. Thus, the current domain must
> have the right to update the mappings of target domain with pages from
> foreign domain.
>
> Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>

Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>

For some reason I only have v3 and cannot find the v4-v7 patches in
my Inbox, although I do have the copies that came via the xen-devel list.
I recall having some transient email issues during that time, so if
Oracle's mail servers have a more aggressive retry policy the messages
could have been lost due to that; I wasn't intending to ignore your patches.

> ---
>   xen/arch/arm/mm.c       |    4 ++--
>   xen/arch/x86/mm.c       |   18 +++++++++++++++---
>   xen/include/xsm/dummy.h |   10 ++++++++--
>   xen/include/xsm/xsm.h   |    6 +++---
>   xen/xsm/flask/hooks.c   |    9 +++++++--
>   5 files changed, 35 insertions(+), 12 deletions(-)
>
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index 654281a..3515526 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -1134,7 +1134,7 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
>           if ( d == NULL )
>               return -ESRCH;
>
> -        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> +        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d, NULL);
>           if ( rc )
>           {
>               rcu_unlock_domain(d);
> @@ -1165,7 +1165,7 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
>           if ( d == NULL )
>               return -ESRCH;
>
> -        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> +        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d, NULL);
>           if ( rc )
>           {
>               rcu_unlock_domain(d);
> diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
> index ae332f4..0cae437 100644
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -4730,7 +4730,7 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
>           if ( d == NULL )
>               return -ESRCH;
>
> -        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
> +        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d, NULL) )
>           {
>               rcu_unlock_domain(d);
>               return -EPERM;
> @@ -4756,7 +4756,7 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
>       case XENMEM_add_to_physmap_range:
>       {
>           struct xen_add_to_physmap_range xatpr;
> -        struct domain *d;
> +        struct domain *d, *fd = NULL;
>
>           if ( copy_from_guest(&xatpr, arg, 1) )
>               return -EFAULT;
> @@ -4769,10 +4769,22 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
>           if ( d == NULL )
>               return -ESRCH;
>
> -        if ( (rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d)) == 0 )
> +        if ( xatpr.space == XENMAPSPACE_gmfn_foreign )
> +        {
> +            fd = get_pg_owner(xatpr.foreign_domid);
> +            if ( fd == NULL )
> +            {
> +                rcu_unlock_domain(d);
> +                return -ESRCH;
> +            }
> +        }
> +        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d, fd);
> +        if ( rc == 0 )
>               rc = xenmem_add_to_physmap_range(d, &xatpr);
>
>           rcu_unlock_domain(d);
> +        if ( fd )
> +            put_pg_owner(fd);
>
>           if ( rc == -EAGAIN )
>               rc = hypercall_create_continuation(
> diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h
> index eb9e1a1..1228e52 100644
> --- a/xen/include/xsm/dummy.h
> +++ b/xen/include/xsm/dummy.h
> @@ -467,10 +467,16 @@ static XSM_INLINE int xsm_pci_config_permission(XSM_DEFAULT_ARG struct domain *d
>       return xsm_default_action(action, current->domain, d);
>   }
>
> -static XSM_INLINE int xsm_add_to_physmap(XSM_DEFAULT_ARG struct domain *d1, struct domain *d2)
> +static XSM_INLINE int xsm_add_to_physmap(XSM_DEFAULT_ARG struct domain *d, struct domain *t, struct domain *f)
>   {
> +    int rc;
> +
>       XSM_ASSERT_ACTION(XSM_TARGET);
> -    return xsm_default_action(action, d1, d2);
> +    rc = xsm_default_action(action, d, t);
> +    if ( f && !rc )
> +        rc = xsm_default_action(action, d, f);
> +
> +    return rc;
>   }
>
>   static XSM_INLINE int xsm_remove_from_physmap(XSM_DEFAULT_ARG struct domain *d1, struct domain *d2)
> diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h
> index 1939453..9ee9543 100644
> --- a/xen/include/xsm/xsm.h
> +++ b/xen/include/xsm/xsm.h
> @@ -90,7 +90,7 @@ struct xsm_operations {
>       int (*memory_adjust_reservation) (struct domain *d1, struct domain *d2);
>       int (*memory_stat_reservation) (struct domain *d1, struct domain *d2);
>       int (*memory_pin_page) (struct domain *d1, struct domain *d2, struct page_info *page);
> -    int (*add_to_physmap) (struct domain *d1, struct domain *d2);
> +    int (*add_to_physmap) (struct domain *d, struct domain *t, struct domain *f);
>       int (*remove_from_physmap) (struct domain *d1, struct domain *d2);
>       int (*claim_pages) (struct domain *d);
>
> @@ -344,9 +344,9 @@ static inline int xsm_memory_pin_page(xsm_default_t def, struct domain *d1, stru
>       return xsm_ops->memory_pin_page(d1, d2, page);
>   }
>
> -static inline int xsm_add_to_physmap(xsm_default_t def, struct domain *d1, struct domain *d2)
> +static inline int xsm_add_to_physmap(xsm_default_t def, struct domain *d, struct domain *t, struct domain *f)
>   {
> -    return xsm_ops->add_to_physmap(d1, d2);
> +    return xsm_ops->add_to_physmap(d, t, f);
>   }
>
>   static inline int xsm_remove_from_physmap(xsm_default_t def, struct domain *d1, struct domain *d2)
> diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
> index 7cdef04..81294b1 100644
> --- a/xen/xsm/flask/hooks.c
> +++ b/xen/xsm/flask/hooks.c
> @@ -1068,9 +1068,14 @@ static inline int flask_tmem_control(void)
>       return domain_has_xen(current->domain, XEN__TMEM_CONTROL);
>   }
>
> -static int flask_add_to_physmap(struct domain *d1, struct domain *d2)
> +static int flask_add_to_physmap(struct domain *d, struct domain *t, struct domain *f)
>   {
> -    return domain_has_perm(d1, d2, SECCLASS_MMU, MMU__PHYSMAP);
> +    int rc;
> +
> +    rc = domain_has_perm(d, t, SECCLASS_MMU, MMU__PHYSMAP);
> +    if ( f && !rc )
> +        rc = domain_has_perm(d, f, SECCLASS_MMU, MMU__MAP_READ|MMU__MAP_WRITE);
> +    return rc;
>   }
>
>   static int flask_remove_from_physmap(struct domain *d1, struct domain *d2)
>