Re: [V10 PATCH 1/4] pvh dom0: construct_dom0 changes

["Roger Pau Monné" <roger.pau@citrix.com>]

On 30/04/14 03:06, Mukesh Rathor wrote:
> This patch changes construct_dom0() to boot in pvh mode:
>   - Make sure dom0 elf supports pvh mode.
>   - Call guest_physmap_add_page for pvh rather than simple p2m setting
>   - Map all non-RAM regions 1:1 upto the end region in e820 or 4GB which
>     ever is higher.
>   - Allocate p2m, copying calculation from toolstack.
>   - Allocate shared info page from the virtual space so that dom0 PT
>     can be updated. Then update p2m for it with the actual mfn.
>   - Since we build the page tables for pvh same as for pv, in
>     pvh_fixup_page_tables_for_hap we replace the mfns with pfns.
> 
> Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
> Reviewed-by: Jan Beulich <jbeulich@suse.com>

I have the following patch on top of yours, in order to add the memory 
removed by the holes to the end of the memory map:

---
diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index 38ed9f6..6f5ba22 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -327,11 +327,13 @@ static __init void pvh_add_mem_mapping(struct domain *d, unsigned long gfn,
  * pvh fixme: The following doesn't map MMIO ranges when they sit above the
  *            highest E820 covered address.
  */
-static __init void pvh_map_all_iomem(struct domain *d)
+static __init void pvh_map_all_iomem(struct domain *d, unsigned long nr_pages)
 {
     unsigned long start_pfn, end_pfn, end = 0, start = 0;
     const struct e820entry *entry;
-    unsigned int i, nump;
+    unsigned int i, j, nump, navail, nmap, nr_holes = 0;
+    struct page_info *page;
+    int rc;
 
     for ( i = 0, entry = e820.map; i < e820.nr_map; i++, entry++ )
     {
@@ -353,6 +355,9 @@ static __init void pvh_map_all_iomem(struct domain *d)
                 nump = end_pfn - start_pfn;
                 /* Add pages to the mapping */
                 pvh_add_mem_mapping(d, start_pfn, start_pfn, nump);
+                if (start_pfn <= nr_pages)
+                    nr_holes += (end_pfn < nr_pages) ?
+                                    nump : (nr_pages - start_pfn);
             }
             start = end;
         }
@@ -369,6 +374,42 @@ static __init void pvh_map_all_iomem(struct domain *d)
         nump = end_pfn - start_pfn;
         pvh_add_mem_mapping(d, start_pfn, start_pfn, nump);
     }
+
+    /*
+     * Add the memory removed by the holes at the end of the
+     * memory map.
+     */
+    for ( i = 0, entry = e820.map; i < e820.nr_map; i++, entry++ )
+    {
+        if ( entry->type != E820_RAM )
+            continue;
+
+        end_pfn = PFN_UP(entry->addr + entry->size);
+        if ( end_pfn <= nr_pages )
+            continue;
+
+        navail = end_pfn - nr_pages;
+        nmap = navail > nr_holes ? nr_holes : navail;
+        start_pfn = PFN_DOWN(entry->addr) < nr_pages ?
+                        nr_pages : PFN_DOWN(entry->addr);
+        page = alloc_domheap_pages(d, get_order_from_pages(nmap), 0);
+        if ( !page )
+            panic("Not enough RAM for domain 0");
+        for ( j = 0; j < nmap; j++ )
+        {
+            rc = guest_physmap_add_page(d, start_pfn + j, page_to_mfn(page), 0);
+            if (rc != 0)
+                panic("Unable to add gpfn %#lx mfn %#lx to Dom0 physmap",
+                      start_pfn + j, page_to_mfn(page));
+            page++;
+
+        }
+        nr_holes -= nmap;
+        if (nr_holes == 0)
+            break;
+    }
+
+    ASSERT(nr_holes == 0);
 }
 
 static __init void dom0_update_physmap(struct domain *d, unsigned long pfn,
@@ -1391,7 +1432,7 @@ int __init construct_dom0(
         pfn = shared_info_paddr >> PAGE_SHIFT;
         dom0_update_physmap(d, pfn, mfn, 0);
 
-        pvh_map_all_iomem(d);
+        pvh_map_all_iomem(d, nr_pages);
     }
 
     if ( d->domain_id == hardware_domid )