* [PATCH] x86/mm/paging: Prevent the guest from faulting on the same gfn when dying
@ 2012-03-12 15:39 Andres Lagar-Cavilla
0 siblings, 0 replies; 3+ messages in thread
From: Andres Lagar-Cavilla @ 2012-03-12 15:39 UTC (permalink / raw)
To: xen-devel; +Cc: andres, tim, olaf, adin
xen/arch/x86/mm/p2m.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
A crashing guest due to paging may hit an "endless" loop faulting repeatedly on
the current paged-out gfn, until the toolstack comes around to killing the
domain.
Unfortunately domain_crash at this point may not pause the vcpu due to the
shutting_down flag, so we pause it explicitly when detecting the condition.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
diff -r dfbcb092aa66 -r 0fe4b3326167 xen/arch/x86/mm/p2m.c
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -988,6 +988,8 @@ void p2m_mem_paging_populate(struct doma
{
gdprintk(XENLOG_ERR, "Domain %hu paging gfn %lx yet no ring "
"in place\n", d->domain_id, gfn);
+ /* Prevent the vcpu from faulting repeatedly on the same gfn */
+ vcpu_pause_nosync(v);
domain_crash(d);
return;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] x86/mm/paging: Prevent the guest from faulting on the same gfn when dying
@ 2012-03-12 15:42 Andres Lagar-Cavilla
2012-03-15 11:32 ` Tim Deegan
0 siblings, 1 reply; 3+ messages in thread
From: Andres Lagar-Cavilla @ 2012-03-12 15:42 UTC (permalink / raw)
To: xen-devel; +Cc: andres, tim, olaf, adin
xen/arch/x86/mm/p2m.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
Please ignore previous post from a minute ago. Use this instead.
A crashing guest due to paging may hit an "endless" loop faulting repeatedly on
the current paged-out gfn, until the toolstack comes around to killing the
domain.
Unfortunately domain_crash at this point may not pause the vcpu due to the
shutting_down flag, so we pause it explicitly when detecting the condition.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
diff -r dfbcb092aa66 -r 88584a17d2da xen/arch/x86/mm/p2m.c
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -988,6 +988,9 @@ void p2m_mem_paging_populate(struct doma
{
gdprintk(XENLOG_ERR, "Domain %hu paging gfn %lx yet no ring "
"in place\n", d->domain_id, gfn);
+ /* Prevent the vcpu from faulting repeatedly on the same gfn */
+ if ( v->domain == d )
+ vcpu_pause_nosync(v);
domain_crash(d);
return;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/mm/paging: Prevent the guest from faulting on the same gfn when dying
2012-03-12 15:42 [PATCH] x86/mm/paging: Prevent the guest from faulting on the same gfn when dying Andres Lagar-Cavilla
@ 2012-03-15 11:32 ` Tim Deegan
0 siblings, 0 replies; 3+ messages in thread
From: Tim Deegan @ 2012-03-15 11:32 UTC (permalink / raw)
To: Andres Lagar-Cavilla; +Cc: andres, adin, olaf, xen-devel
At 11:42 -0400 on 12 Mar (1331552563), Andres Lagar-Cavilla wrote:
> A crashing guest due to paging may hit an "endless" loop faulting repeatedly on
> the current paged-out gfn, until the toolstack comes around to killing the
> domain.
>
> Unfortunately domain_crash at this point may not pause the vcpu due to the
> shutting_down flag, so we pause it explicitly when detecting the condition.
Applied, thanks.
Tim.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-03-15 11:32 ` Tim Deegan
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