Jan Beulich
2010-Jun-15 11:45 UTC
[Xen-devel] [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 <jbeulich@novell.com>
--- 2010-06-15.orig/tools/libxc/xc_domain_save.c 2010-06-01 13:39:57.000000000
+0200
+++ 2010-06-15/tools/libxc/xc_domain_save.c 2010-06-15 09:32:42.000000000 +0200
@@ -1288,58 +1288,64 @@ int xc_domain_save(xc_interface *xch, in
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)");
--- 2010-06-15.orig/xen/arch/x86/domctl.c 2010-03-02 09:11:28.000000000 +0100
+++ 2010-06-15/xen/arch/x86/domctl.c 2010-06-15 09:32:42.000000000 +0200
@@ -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;
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http://lists.xensource.com/xen-devel
Keir Fraser
2010-Jun-15 12:22 UTC
Re: [Xen-devel] [PATCH] don''t save Xen heap pages during domain save
I''ve applied all your patches as of xen-unstable:21621. Are they all suitable for Xen 4.0.x do you think? What about 3.4.x? Thanks, Keir On 15/06/2010 12:45, "Jan Beulich" <JBeulich@novell.com> wrote:> 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> > > --- 2010-06-15.orig/tools/libxc/xc_domain_save.c 2010-06-01 13:39:57.000000000 > +0200 > +++ 2010-06-15/tools/libxc/xc_domain_save.c 2010-06-15 09:32:42.000000000 > +0200 > @@ -1288,58 +1288,64 @@ int xc_domain_save(xc_interface *xch, in > 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)"); > --- 2010-06-15.orig/xen/arch/x86/domctl.c 2010-03-02 09:11:28.000000000 +0100 > +++ 2010-06-15/xen/arch/x86/domctl.c 2010-06-15 09:32:42.000000000 +0200 > @@ -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; > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Jan Beulich
2010-Jun-15 12:39 UTC
Re: [Xen-devel] [PATCH] don''t save Xen heap pages during domain save
>>> On 15.06.10 at 14:22, Keir Fraser <keir.fraser@eu.citrix.com> wrote: > I''ve applied all your patches as of xen-unstable:21621. Are they all > suitable for Xen 4.0.x do you think? What about 3.4.x?No, perhaps not all of them. Some of them fixes issues that must have been introduced recently, so they would qualify for older trees only if the respective base patches also went there. That is, - the domain save one likely is a candidate, but it should see some broader testing first - the pv cpuid masking one likely is a candidate, together with Intel''s original one (whether just for 4.0 or also for 3.4 is more difficult to judge) - the IRQ signed-ness one should be applicable to 4.0 only - the MCE, superpage, wrmsr warning, and pyxc ones fall into the above category - the LZO patches, while supposedly safe, don''t look like backporting candidates to me Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel