libxc: unify handling of vNUMA layout

This patch does the following:
1. Use local variables for dummy vNUMA layout in PV case.
2. Avoid leaking dummy layout back to caller in PV case.
3. Use local variables to reference vNUMA layout (whether it is dummy
   or provided by caller) for both PV and HVM.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

tools/libxc/xc_dom_x86.c

@@ -762,6 +762,11 @@ int arch_setup_meminit(struct xc_dom_image *dom)
     int rc;
     xen_pfn_t pfn, allocsz, mfn, total, pfn_base;
     int i, j;
+    xen_vmemrange_t dummy_vmemrange[1];
+    unsigned int dummy_vnode_to_pnode[1];
+    xen_vmemrange_t *vmemranges;
+    unsigned int *vnode_to_pnode;
+    unsigned int nr_vmemranges, nr_vnodes;
 
     rc = x86_compat(dom->xch, dom->guest_domid, dom->guest_type);
     if ( rc )
@@ -826,27 +831,33 @@ int arch_setup_meminit(struct xc_dom_image *dom)
          */
         if ( dom->nr_vmemranges == 0 )
         {
-            dom->nr_vmemranges = 1;
-            dom->vmemranges = xc_dom_malloc(dom, sizeof(*dom->vmemranges));
-            dom->vmemranges[0].start = 0;
-            dom->vmemranges[0].end   = (uint64_t)dom->total_pages << PAGE_SHIFT;
-            dom->vmemranges[0].flags = 0;
-            dom->vmemranges[0].nid   = 0;
+            nr_vmemranges = 1;
+            vmemranges = dummy_vmemrange;
+            vmemranges[0].start = 0;
+            vmemranges[0].end   = (uint64_t)dom->total_pages << PAGE_SHIFT;
+            vmemranges[0].flags = 0;
+            vmemranges[0].nid   = 0;
 
-            dom->nr_vnodes = 1;
-            dom->vnode_to_pnode = xc_dom_malloc(dom,
-                                      sizeof(*dom->vnode_to_pnode));
-            dom->vnode_to_pnode[0] = XC_NUMA_NO_NODE;
+            nr_vnodes = 1;
+            vnode_to_pnode = dummy_vnode_to_pnode;
+            vnode_to_pnode[0] = XC_NUMA_NO_NODE;
+        }
+        else
+        {
+            nr_vmemranges = dom->nr_vmemranges;
+            nr_vnodes = dom->nr_vnodes;
+            vmemranges = dom->vmemranges;
+            vnode_to_pnode = dom->vnode_to_pnode;
         }
 
         total = dom->p2m_size = 0;
-        for ( i = 0; i < dom->nr_vmemranges; i++ )
+        for ( i = 0; i < nr_vmemranges; i++ )
         {
-            total += ((dom->vmemranges[i].end - dom->vmemranges[i].start)
+            total += ((vmemranges[i].end - vmemranges[i].start)
                       >> PAGE_SHIFT);
             dom->p2m_size =
-                dom->p2m_size > (dom->vmemranges[i].end >> PAGE_SHIFT) ?
-                dom->p2m_size : (dom->vmemranges[i].end >> PAGE_SHIFT);
+                dom->p2m_size > (vmemranges[i].end >> PAGE_SHIFT) ?
+                dom->p2m_size : (vmemranges[i].end >> PAGE_SHIFT);
         }
         if ( total != dom->total_pages )
         {
@@ -864,19 +875,19 @@ int arch_setup_meminit(struct xc_dom_image *dom)
             dom->p2m_host[pfn] = INVALID_P2M_ENTRY;
 
         /* allocate guest memory */
-        for ( i = 0; i < dom->nr_vmemranges; i++ )
+        for ( i = 0; i < nr_vmemranges; i++ )
         {
             unsigned int memflags;
             uint64_t pages;
-            unsigned int pnode = dom->vnode_to_pnode[dom->vmemranges[i].nid];
+            unsigned int pnode = vnode_to_pnode[vmemranges[i].nid];
 
             memflags = 0;
             if ( pnode != XC_NUMA_NO_NODE )
                 memflags |= XENMEMF_exact_node(pnode);
 
-            pages = (dom->vmemranges[i].end - dom->vmemranges[i].start)
+            pages = (vmemranges[i].end - vmemranges[i].start)
                 >> PAGE_SHIFT;
-            pfn_base = dom->vmemranges[i].start >> PAGE_SHIFT;
+            pfn_base = vmemranges[i].start >> PAGE_SHIFT;
 
             for ( pfn = pfn_base; pfn < pfn_base+pages; pfn++ )
                 dom->p2m_host[pfn] = pfn;

tools/libxc/xc_hvm_build_x86.c

@@ -257,7 +257,9 @@ static int setup_guest(xc_interface *xch,
     uint64_t total_pages;
     xen_vmemrange_t dummy_vmemrange[2];
     unsigned int dummy_vnode_to_pnode[1];
-    bool use_dummy = false;
+    xen_vmemrange_t *vmemranges;
+    unsigned int *vnode_to_pnode;
+    unsigned int nr_vmemranges, nr_vnodes;
 
     memset(&elf, 0, sizeof(elf));
     if ( elf_init(&elf, image, image_size) != 0 )
@@ -290,7 +292,7 @@ static int setup_guest(xc_interface *xch,
         dummy_vmemrange[0].end   = args->lowmem_end;
         dummy_vmemrange[0].flags = 0;
         dummy_vmemrange[0].nid   = 0;
-        args->nr_vmemranges = 1;
+        nr_vmemranges = 1;
 
         if ( args->highmem_end > (1ULL << 32) )
         {
@@ -299,14 +301,13 @@ static int setup_guest(xc_interface *xch,
             dummy_vmemrange[1].flags = 0;
             dummy_vmemrange[1].nid   = 0;
 
-            args->nr_vmemranges++;
+            nr_vmemranges++;
         }
 
         dummy_vnode_to_pnode[0] = XC_NUMA_NO_NODE;
-        args->nr_vnodes = 1;
-        args->vmemranges = dummy_vmemrange;
-        args->vnode_to_pnode = dummy_vnode_to_pnode;
-        use_dummy = true;
+        nr_vnodes = 1;
+        vmemranges = dummy_vmemrange;
+        vnode_to_pnode = dummy_vnode_to_pnode;
     }
     else
     {
@@ -315,16 +316,21 @@ static int setup_guest(xc_interface *xch,
             PERROR("Cannot enable vNUMA and PoD at the same time");
             goto error_out;
         }
+
+        nr_vmemranges = args->nr_vmemranges;
+        nr_vnodes = args->nr_vnodes;
+        vmemranges = args->vmemranges;
+        vnode_to_pnode = args->vnode_to_pnode;
     }
 
     total_pages = 0;
     p2m_size = 0;
-    for ( i = 0; i < args->nr_vmemranges; i++ )
+    for ( i = 0; i < nr_vmemranges; i++ )
     {
-        total_pages += ((args->vmemranges[i].end - args->vmemranges[i].start)
+        total_pages += ((vmemranges[i].end - vmemranges[i].start)
                         >> PAGE_SHIFT);
-        p2m_size = p2m_size > (args->vmemranges[i].end >> PAGE_SHIFT) ?
-            p2m_size : (args->vmemranges[i].end >> PAGE_SHIFT);
+        p2m_size = p2m_size > (vmemranges[i].end >> PAGE_SHIFT) ?
+            p2m_size : (vmemranges[i].end >> PAGE_SHIFT);
     }
 
     if ( total_pages != (args->mem_size >> PAGE_SHIFT) )
@@ -360,12 +366,12 @@ static int setup_guest(xc_interface *xch,
 
     for ( i = 0; i < p2m_size; i++ )
         page_array[i] = ((xen_pfn_t)-1);
-    for ( vmemid = 0; vmemid < args->nr_vmemranges; vmemid++ )
+    for ( vmemid = 0; vmemid < nr_vmemranges; vmemid++ )
     {
         uint64_t pfn;
 
-        for ( pfn = args->vmemranges[vmemid].start >> PAGE_SHIFT;
-              pfn < args->vmemranges[vmemid].end >> PAGE_SHIFT;
+        for ( pfn = vmemranges[vmemid].start >> PAGE_SHIFT;
+              pfn < vmemranges[vmemid].end >> PAGE_SHIFT;
               pfn++ )
             page_array[pfn] = pfn;
     }
@@ -417,29 +423,29 @@ static int setup_guest(xc_interface *xch,
         xch, dom, 0xa0, 0, memflags, &page_array[0x00]);
 
     stat_normal_pages = 0;
-    for ( vmemid = 0; vmemid < args->nr_vmemranges; vmemid++ )
+    for ( vmemid = 0; vmemid < nr_vmemranges; vmemid++ )
     {
         unsigned int new_memflags = memflags;
         uint64_t end_pages;
-        unsigned int vnode = args->vmemranges[vmemid].nid;
-        unsigned int pnode = args->vnode_to_pnode[vnode];
+        unsigned int vnode = vmemranges[vmemid].nid;
+        unsigned int pnode = vnode_to_pnode[vnode];
 
         if ( pnode != XC_NUMA_NO_NODE )
             new_memflags |= XENMEMF_exact_node(pnode);
 
-        end_pages = args->vmemranges[vmemid].end >> PAGE_SHIFT;
+        end_pages = vmemranges[vmemid].end >> PAGE_SHIFT;
         /*
          * Consider vga hole belongs to the vmemrange that covers
          * 0xA0000-0xC0000. Note that 0x00000-0xA0000 is populated just
          * before this loop.
          */
-        if ( args->vmemranges[vmemid].start == 0 )
+        if ( vmemranges[vmemid].start == 0 )
         {
             cur_pages = 0xc0;
             stat_normal_pages += 0xc0;
         }
         else
-            cur_pages = args->vmemranges[vmemid].start >> PAGE_SHIFT;
+            cur_pages = vmemranges[vmemid].start >> PAGE_SHIFT;
 
         while ( (rc == 0) && (end_pages > cur_pages) )
         {
@@ -679,12 +685,6 @@ static int setup_guest(xc_interface *xch,
  error_out:
     rc = -1;
  out:
-    if ( use_dummy )
-    {
-        args->nr_vnodes = 0;
-        args->vmemranges = NULL;
-        args->vnode_to_pnode = NULL;
-    }
     if ( elf_check_broken(&elf) )
         ERROR("HVM ELF broken: %s", elf_check_broken(&elf));