Xen devel - Jan 2013 - [RFC PATCH 2/16]: PVH xen: add XENMEM_add_to_physmap_range

In this patch we add a new function xenmem_add_to_physmap_range(), and
change xenmem_add_to_physmap_once parameters so it can be called from
xenmem_add_to_physmap_range. There is no PVH specific change here.

BTW, there are 16 patches and not 15. Sorry, corrected the subject.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>


diff -r 278d7a933d88 -r ede1afe68962 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c	Fri Jan 11 16:19:40 2013 -0800
+++ b/xen/arch/x86/mm.c	Fri Jan 11 16:20:38 2013 -0800
@@ -4218,8 +4218,8 @@ static int handle_iomem_range(unsigned l
 }
 
 static int xenmem_add_to_physmap_once(
-    struct domain *d,
-    const struct xen_add_to_physmap *xatp)
+    struct domain *d, uint16_t xatp_space, domid_t foreign_domid,
+    unsigned long xatp_idx, unsigned long xatp_gpfn)
 {
     struct page_info *page = NULL;
     unsigned long gfn = 0; /* gcc ... */
@@ -4227,10 +4227,10 @@ static int xenmem_add_to_physmap_once(
     int rc;
     p2m_type_t p2mt;
 
-    switch ( xatp->space )
+    switch ( xatp_space )
     {
         case XENMAPSPACE_shared_info:
-            if ( xatp->idx == 0 )
+            if ( xatp_idx == 0 )
                 mfn = virt_to_mfn(d->shared_info);
             break;
         case XENMAPSPACE_grant_table:
@@ -4239,9 +4239,9 @@ static int xenmem_add_to_physmap_once(
             if ( d->grant_table->gt_version == 0 )
                 d->grant_table->gt_version = 1;
 
-            idx = xatp->idx;
+            idx = xatp_idx;
             if ( d->grant_table->gt_version == 2 &&
-                 (xatp->idx & XENMAPIDX_grant_table_status) )
+                 (xatp_idx & XENMAPIDX_grant_table_status) )
             {
                 idx &= ~XENMAPIDX_grant_table_status;
                 if ( idx < nr_status_frames(d->grant_table) )
@@ -4263,9 +4263,9 @@ static int xenmem_add_to_physmap_once(
         case XENMAPSPACE_gmfn:
         {
             p2m_type_t p2mt;
-            gfn = xatp->idx;
-
-            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
+            gfn = xatp_idx;
+
+            idx = mfn_x(get_gfn_unshare(d, xatp_idx, &p2mt));
             /* If the page is still shared, exit early */
             if ( p2m_is_shared(p2mt) )
             {
@@ -4286,8 +4286,8 @@ static int xenmem_add_to_physmap_once(
     {
         if ( page )
             put_page(page);
-        if ( xatp->space == XENMAPSPACE_gmfn ||
-             xatp->space == XENMAPSPACE_gmfn_range )
+        if ( xatp_space == XENMAPSPACE_gmfn ||
+             xatp_space == XENMAPSPACE_gmfn_range )
             put_gfn(d, gfn);
         return -EINVAL;
     }
@@ -4298,41 +4298,41 @@ static int xenmem_add_to_physmap_once(
         put_page(page);
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
+    prev_mfn = mfn_x(get_gfn(d, xatp_gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
             /* Xen heap frames are simply unhooked from this phys slot. */
-            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn,
PAGE_ORDER_4K);
+            guest_physmap_remove_page(d, xatp_gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */
-            guest_remove_page(d, xatp->gpfn);
+            guest_remove_page(d, xatp_gpfn);
     }
     /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
-    put_gfn(d, xatp->gpfn);
+    put_gfn(d, xatp_gpfn);
 
     /* Unmap from old location, if any. */
     gpfn = get_gpfn_from_mfn(mfn);
     ASSERT( gpfn != SHARED_M2P_ENTRY );
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( xatp_space == XENMAPSPACE_gmfn ||
+         xatp_space == XENMAPSPACE_gmfn_range )
         ASSERT( gpfn == gfn );
     if ( gpfn != INVALID_M2P_ENTRY )
         guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
+    rc = guest_physmap_add_page(d, xatp_gpfn, mfn, PAGE_ORDER_4K);
 
     /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( xatp_space == XENMAPSPACE_gmfn ||
+         xatp_space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
     domain_unlock(d);
 
     return rc;
 }
 
-static int xenmem_add_to_physmap(struct domain *d,
+static noinline int xenmem_add_to_physmap(struct domain *d,
                                  struct xen_add_to_physmap *xatp)
 {
     struct xen_add_to_physmap start_xatp;
@@ -4346,7 +4346,8 @@ static int xenmem_add_to_physmap(struct 
         start_xatp = *xatp;
         while ( xatp->size > 0 )
         {
-            rc = xenmem_add_to_physmap_once(d, xatp);
+            rc = xenmem_add_to_physmap_once(d, xatp->space, -1,
+                                            xatp->idx, xatp->gpfn);
             if ( rc < 0 )
                 return rc;
 
@@ -4372,7 +4373,50 @@ static int xenmem_add_to_physmap(struct 
         return rc;
     }
 
-    return xenmem_add_to_physmap_once(d, xatp);
+    return xenmem_add_to_physmap_once(d, xatp->space, -1,
+                                      xatp->idx, xatp->gpfn);
+}
+
+static noinline int xenmem_add_to_physmap_range(struct domain *d,
+                                       struct xen_add_to_physmap_range *xatpr)
+{
+    int rc;
+
+    /* Process entries in reverse order to allow continuations */
+    while ( xatpr->size > 0 )
+    {
+        xen_ulong_t idx;
+        xen_pfn_t gpfn;
+
+        rc = copy_from_guest_offset(&idx, xatpr->idxs, xatpr->size-1,
1);
+        if ( rc < 0 )
+            goto out;
+
+        rc = copy_from_guest_offset(&gpfn, xatpr->gpfns,
xatpr->size-1, 1);
+        if ( rc < 0 )
+            goto out;
+
+        rc = xenmem_add_to_physmap_once(d, xatpr->space,
xatpr->foreign_domid,
+                                        idx, gpfn);
+
+	if (rc)
+            goto out;
+
+        xatpr->size--;
+
+        /* Check for continuation if it''s not the last interation */
+        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            goto out;
+        }
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+
 }
 
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
@@ -4389,6 +4433,10 @@ long arch_memory_op(int op, XEN_GUEST_HA
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
+        /* This one is only supported for add_to_physmap_range */
+        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
+            return -EINVAL;
+
         rc = rcu_lock_target_domain_by_id(xatp.domid, &d);
         if ( rc != 0 )
             return rc;
@@ -4416,6 +4464,32 @@ long arch_memory_op(int op, XEN_GUEST_HA
         return rc;
     }
 
+    case XENMEM_add_to_physmap_range:
+    {
+        struct xen_add_to_physmap_range xatpr;
+        struct domain *d;
+
+        if ( copy_from_guest(&xatpr, arg, 1) )
+            return -EFAULT;
+
+        rc = rcu_lock_target_domain_by_id(xatpr.domid, &d);
+        if ( rc != 0 )
+            return rc;
+
+        rc = xenmem_add_to_physmap_range(d, &xatpr);
+
+        rcu_unlock_domain(d);
+
+        if ( rc && copy_to_guest(arg, &xatpr, 1) )
+            rc = -EFAULT;
+
+        if ( rc == -EAGAIN )
+            rc = hypercall_create_continuation(
+                __HYPERVISOR_memory_op, "ih", op, arg);
+
+        return rc;
+    }
+
     case XENMEM_set_memory_map:
     {
         struct xen_foreign_memory_map fmap;

On 12/01/2013 01:28, "Mukesh Rathor" <mukesh.rathor@oracle.com>
wrote:
> In this patch we add a new function xenmem_add_to_physmap_range(), and
> change xenmem_add_to_physmap_once parameters so it can be called from
> xenmem_add_to_physmap_range. There is no PVH specific change here.
> 
> BTW, there are 16 patches and not 15. Sorry, corrected the subject.
> 
> Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
> 
> 
> diff -r 278d7a933d88 -r ede1afe68962 xen/arch/x86/mm.c
> --- a/xen/arch/x86/mm.c Fri Jan 11 16:19:40 2013 -0800
> +++ b/xen/arch/x86/mm.c Fri Jan 11 16:20:38 2013 -0800
> @@ -4218,8 +4218,8 @@ static int handle_iomem_range(unsigned l
>  }
>  
>  static int xenmem_add_to_physmap_once(
> -    struct domain *d,
> -    const struct xen_add_to_physmap *xatp)
> +    struct domain *d, uint16_t xatp_space, domid_t foreign_domid,
> +    unsigned long xatp_idx, unsigned long xatp_gpfn)
The new caller should pack these arguments into a xen_add_to_physmap struct
like all the others do. Don''t atomise struct arguments like this,
it''s
gross.

 -- Keir

On Sat, 12 Jan 2013 07:51:29 +0000
Keir Fraser <keir.xen@gmail.com> wrote:
> On 12/01/2013 01:28, "Mukesh Rathor"
<mukesh.rathor@oracle.com> wrote:
> 
> > In this patch we add a new function xenmem_add_to_physmap_range(),
> > and change xenmem_add_to_physmap_once parameters so it can be
> > called from xenmem_add_to_physmap_range. There is no PVH specific
> > change here.
> > 
> > BTW, there are 16 patches and not 15. Sorry, corrected the subject.
> > 
> > Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
> > 
> > 
> > diff -r 278d7a933d88 -r ede1afe68962 xen/arch/x86/mm.c
> > --- a/xen/arch/x86/mm.c Fri Jan 11 16:19:40 2013 -0800
> > +++ b/xen/arch/x86/mm.c Fri Jan 11 16:20:38 2013 -0800
> > @@ -4218,8 +4218,8 @@ static int handle_iomem_range(unsigned l
> >  }
> >  
> >  static int xenmem_add_to_physmap_once(
> > -    struct domain *d,
> > -    const struct xen_add_to_physmap *xatp)
> > +    struct domain *d, uint16_t xatp_space, domid_t foreign_domid,
> > +    unsigned long xatp_idx, unsigned long xatp_gpfn)
> 
> The new caller should pack these arguments into a xen_add_to_physmap
> struct like all the others do. Don''t atomise struct arguments like
> this, it''s gross.
> 
>  -- Keir
> 
Ok, done.