File 21615-dont-save-xen-heap-pages.patch of Package xen

Overview Repositories Revisions Requests Users Attributes Meta

File 21615-dont-save-xen-heap-pages.patch of Package xen (Revision d1c2ddf2109819358796059425bd48bc)

Currently displaying revision d1c2ddf2109819358796059425bd48bc , Show latest

# HG changeset patch
# User Keir Fraser <keir.fraser@citrix.com>
# Date 1276604289 -3600
# Node ID a2cc1db1af9c8f9b148c80f8b2c3f64bde7542f9
# Parent  094b826a2b8e2c17fe7004923352d459e0c23f13
Don't save Xen heap pages during domain save
References: bnc#609153

As discussed in the thread starting at
http://lists.xensource.com/archives/html/xen-devel/2010-05/msg01383.html,
don't save Xen heap pages in order to avoid overallocation when the
domain gets restored, as those pages would get (temporarily) backed
with normal RAM pages by the restore code.

This requires making DOMCTL_getpageframeinfo{2,3} usable for HVM
guests, meaning that the input to these must be treated as GMFNs.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

Index: xen-4.0.1-testing/tools/libxc/xc_domain_save.c
===================================================================
--- xen-4.0.1-testing.orig/tools/libxc/xc_domain_save.c
+++ xen-4.0.1-testing/tools/libxc/xc_domain_save.c
@@ -1282,58 +1282,64 @@ int xc_domain_save(int xc_handle, int io
                 goto out;
             }
 
-            if ( hvm )
+            /* Get page types */
+            if ( xc_get_pfn_type_batch(xc_handle, dom, batch, pfn_type) )
             {
-                /* Look for and skip completely empty batches. */
-                for ( j = 0; j < batch; j++ )
-                {
-                    if ( !pfn_err[j] )
-                        break;
-                    pfn_type[j] |= XEN_DOMCTL_PFINFO_XTAB;
-                }
-                if ( j == batch )
-                {
-                    munmap(region_base, batch*PAGE_SIZE);
-                    continue; /* bail on this batch: no valid pages */
-                }
-                for ( ; j < batch; j++ )
-                    if ( pfn_err[j] )
-                        pfn_type[j] |= XEN_DOMCTL_PFINFO_XTAB;
+                ERROR("get_pfn_type_batch failed");
+                goto out;
             }
-            else
+
+            for ( run = j = 0; j < batch; j++ )
             {
-                /* Get page types */
-                if ( xc_get_pfn_type_batch(xc_handle, dom, batch, pfn_type) )
-                {
-                    ERROR("get_pfn_type_batch failed");
-                    goto out;
-                }
+                unsigned long gmfn = pfn_batch[j];
+
+                if ( !hvm )
+                    gmfn = pfn_to_mfn(gmfn);
 
-                for ( j = 0; j < batch; j++ )
+                if ( pfn_err[j] )
                 {
-                    unsigned long mfn = pfn_to_mfn(pfn_batch[j]);
-                    
                     if ( pfn_type[j] == XEN_DOMCTL_PFINFO_XTAB )
-                    {
-                        DPRINTF("type fail: page %i mfn %08lx\n", 
-                                j, mfn);
                         continue;
-                    }
-                    
-                    if ( debug )
+                    DPRINTF("map fail: page %i mfn %08lx err %d\n",
+                            j, gmfn, pfn_err[j]);
+                    pfn_type[j] = XEN_DOMCTL_PFINFO_XTAB;
+                    continue;
+                }
+
+                if ( pfn_type[j] == XEN_DOMCTL_PFINFO_XTAB )
+                {
+                    DPRINTF("type fail: page %i mfn %08lx\n", j, gmfn);
+                    continue;
+                }
+
+                /* canonicalise mfn->pfn */
+                pfn_type[j] |= pfn_batch[j];
+                ++run;
+
+                if ( debug )
+                {
+                    if ( hvm )
+                        DPRINTF("%d pfn=%08lx sum=%08lx\n",
+                                iter,
+                                pfn_type[j],
+                                csum_page(region_base + (PAGE_SIZE*j)));
+                    else
                         DPRINTF("%d pfn= %08lx mfn= %08lx [mfn]= %08lx"
                                 " sum= %08lx\n",
                                 iter,
-                                pfn_type[j] | pfn_batch[j],
-                                mfn,
-                                mfn_to_pfn(mfn),
+                                pfn_type[j],
+                                gmfn,
+                                mfn_to_pfn(gmfn),
                                 csum_page(region_base + (PAGE_SIZE*j)));
-                    
-                    /* canonicalise mfn->pfn */
-                    pfn_type[j] |= pfn_batch[j];
                 }
             }
 
+            if ( !run )
+            {
+                munmap(region_base, batch*PAGE_SIZE);
+                continue; /* bail on this batch: no valid pages */
+            }
+
             if ( write_exact(io_fd, &batch, sizeof(unsigned int)) )
             {
                 PERROR("Error when writing to state file (2)");
Index: xen-4.0.1-testing/xen/arch/x86/domctl.c
===================================================================
--- xen-4.0.1-testing.orig/xen/arch/x86/domctl.c
+++ xen-4.0.1-testing/xen/arch/x86/domctl.c
@@ -206,11 +206,12 @@ long arch_do_domctl(
 
                 for ( j = 0; j < k; j++ )
                 {
-                    unsigned long type = 0, mfn = arr[j];
+                    unsigned long type = 0, mfn = gmfn_to_mfn(d, arr[j]);
 
                     page = mfn_to_page(mfn);
 
-                    if ( unlikely(!mfn_valid(mfn)) )
+                    if ( unlikely(!mfn_valid(mfn)) ||
+                         unlikely(is_xen_heap_mfn(mfn)) )
                         type = XEN_DOMCTL_PFINFO_XTAB;
                     else if ( xsm_getpageframeinfo(page) != 0 )
                         ;
@@ -305,14 +306,15 @@ long arch_do_domctl(
             for ( j = 0; j < k; j++ )
             {      
                 struct page_info *page;
-                unsigned long mfn = arr32[j];
+                unsigned long mfn = gmfn_to_mfn(d, arr32[j]);
 
                 page = mfn_to_page(mfn);
 
                 if ( domctl->cmd == XEN_DOMCTL_getpageframeinfo3)
                     arr32[j] = 0;
 
-                if ( unlikely(!mfn_valid(mfn)) )
+                if ( unlikely(!mfn_valid(mfn)) ||
+                     unlikely(is_xen_heap_mfn(mfn)) )
                     arr32[j] |= XEN_DOMCTL_PFINFO_XTAB;
                 else if ( xsm_getpageframeinfo(page) != 0 )
                     continue;

Places

File 21615-dont-save-xen-heap-pages.patch of Package xen (Revision d1c2ddf2109819358796059425bd48bc)

Places