|
xen-devel
Re: [Xen-devel] Questions about sh_prefetch and log_dirty
Hi, Sorry to bother you again.
I made a mistake when I explain my problem. My code can successfully
migrate the domU TO MODIFIED Xen. But when a domU is migrated
from Modified Xen to a Unmodified Xen. The clock is frozen. I got in
console of that domU with "xm console" and got error messages:
Timer ISR/0: Time went backwards: delta=-33260965833
delta_cpu=-33250965833 shadow=541029605945 off=567446658
processed=574858018252 cpu_processed=574848018252
0: 574848018252
Timer ISR/0: Time went backwards: delta=-31534624494
delta_cpu=-31524624494 shadow=543029632891 off=293761045
processed=574858018252 cpu_processed=574848018252
0: 574848018252
Timer ISR/0: Time went backwards: delta=-30670414300
delta_cpu=-30660414300 shadow=544029644694 off=157959445
processed=574858018252 cpu_processed=574848018252
0: 574848018252
Timer ISR/0: Time went backwards: delta=-29118214802
delta_cpu=-29108214802 shadow=545029657756 off=710145854
processed=574858018252 cpu_processed=574848018252
0: 574848018252
Timer ISR/0: Time went backwards: delta=-28974426202
delta_cpu=-28964426202 shadow=545029657756 off=853934423
processed=574858018252 cpu_processed=574848018252
0: 574848018252
Timer ISR/0: Time went backwards: delta=-28702177774
delta_cpu=-28692177774 shadow=546029671231 off=126169401
processed=574858018252 cpu_processed=574848018252
0: 574848018252
Timer ISR/0: Time went backwards: delta=-28542229390
delta_cpu=-28532229390 shadow=546029671231 off=286117763
processed=574858018252 cpu_processed=574848018252
0: 574848018252
Timer ISR/0: Time went backwards: delta=-28413103192
delta_cpu=-28403103192 shadow=546029671231 off=415243991
processed=574858018252 cpu_processed=574848018252
0: 574848018252
I could still login to that dom with SSH, I found the clock was not
going.
Here is my code, most of it is just a copy of sh_prefetch();
static void sh_prebuild(struct vcpu *v, walk_t gw,
shadow_l1e_t *ptr_sl1e, mfn_t sl1mfn,
unsigned int countl, unsigned int countr)
{
int i, distr,distl;
gfn_t gfn;
mfn_t gmfn;
guest_l1e_t *gl1p = NULL, gl1e;
shadow_l1e_t sl1e;
u32 gflags;
p2m_type_t p2mt;
struct page_info *pg;
distl = ((unsigned long)ptr_sl1e & ~PAGE_MASK) / sizeof sl1e;
distr = (PAGE_SIZE - ((unsigned long)ptr_sl1e & ~PAGE_MASK)) /
sizeof sl1e;
if ( distl > countl )
distl = countl;
if ( distr > countr + 1 )
distr = countr + 1;
if ( !mfn_valid(gw.l1mfn) )
return;
gl1p = sh_map_domain_page(gw.l1mfn);
gl1p += guest_l1_table_offset(gw.va);
ptr_sl1e -= distl;
distl = 0-distl;
for ( i = distl; i < distr ; i++ )
{
if ( i == 0 )
{
ptr_sl1e += 1;
continue;
}
if ( ptr_sl1e->l1 != 0 )
break;
if ( mfn_valid(gw.l1mfn) )
{
gl1e = *(gl1p + i);
gflags = guest_l1e_get_flags(gl1e);
if ( (gflags & _PAGE_PRESENT)
&& (!(gflags & _PAGE_ACCESSED)
|| ((gflags & _PAGE_RW) && !(gflags
& _PAGE_DIRTY))) )
break;
}
else
{
ASSERT(guest_l2e_get_flags(gw.l2e) & _PAGE_PSE);
gl1e = guest_l1e_from_gfn(
_gfn(gfn_x(guest_l1e_get_gfn(gw.l1e)) + i),
guest_l1e_get_flags(gw.l1e));
}
gfn = guest_l1e_get_gfn(gl1e);
gmfn = gfn_to_mfn(v->domain, gfn, &p2mt);
pg = mfn_to_page(gmfn);
if ( mfn_valid(gmfn)
&& ((pg->u.inuse.type_info &
PGT_type_mask)==PGT_writable_page) )
{
l1e_propagate_from_guest(v, gl1e, gmfn, &sl1e,
ft_demand_write, p2mt);
(void) shadow_set_l1e(v, ptr_sl1e, sl1e, sl1mfn);
}
ptr_sl1e += 1;
}
if ( gl1p != NULL )
sh_unmap_domain_page(gl1p);
}
Tim Deegan wrote:
At 14:08 +0100 on 24 Jun (1245852490), David Knight wrote:
Could it be possible that xen is in log_dirty_mode when a DomU is
immigrating into it ?
No; and if it were it wouldn't matter since the domain being migrated
into isn't running.
Cheers,
Tim.
I just want to make the faulted page and its following
pages writable and marked as dirty after a write_protect
page_fault. The function "sh_prebuild" is called in the
sh_page_fault() right before sh_prefetch():
---------------sh_page_fault()-----------------
if ( ( shadow_mode_log_dirty(v->domain) )
&& ( ft == ft_demand_write ) )
sh_prebuild(.......);
..............
I got problems when I migrate. The code can successfully
migrate the domainU to another UNMODIFIED Xen. But when I
migrate a domainU from UNMODIFIED Xen back to this MODIFIED
Xen, the domU's clock is frozen, I use "xm console" to get
in domU's console, but I just got about 6 TSC error messages
and no other respond.
I am using 32-bit PV domain, no-PSE.
Does someone know any reasons? Thanks.
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx<mailto:Xen-devel@xxxxxxxxxxxxxxxxxxx>
http://lists.xensource.com/xen-devel
|
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
Home