From 3aff5e194857d587800365086290e349a1655e3d Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Tue, 15 Jun 2010 13:18:09 +0100 Subject: [PATCH] Don't save Xen heap pages during domain save 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 --- tools/libxc/xc_domain_save.c | 82 +++++++++++++++++++----------------- xen/arch/x86/domctl.c | 10 +++-- 2 files changed, 50 insertions(+), 42 deletions(-) diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c index 2cc8a8cf23..cc6bd1318e 100644 --- a/tools/libxc/xc_domain_save.c +++ b/tools/libxc/xc_domain_save.c @@ -1288,58 +1288,64 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter goto out; } - if ( hvm ) + /* Get page types */ + if ( xc_get_pfn_type_batch(xch, 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; + PERROR("get_pfn_type_batch failed"); + goto out; } - else + + for ( run = j = 0; j < batch; j++ ) { - /* Get page types */ - if ( xc_get_pfn_type_batch(xch, dom, batch, pfn_type) ) - { - PERROR("get_pfn_type_batch failed"); - goto out; - } + unsigned long gmfn = pfn_batch[j]; - for ( j = 0; j < batch; j++ ) + if ( !hvm ) + gmfn = pfn_to_mfn(gmfn); + + 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 ( wrexact(io_fd, &batch, sizeof(unsigned int)) ) { PERROR("Error when writing to state file (2)"); diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c index 2fc24c9fd7..fdbdb2210e 100644 --- a/xen/arch/x86/domctl.c +++ b/xen/arch/x86/domctl.c @@ -207,11 +207,12 @@ 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 ) ; @@ -306,14 +307,15 @@ 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; -- 2.30.2