fix c/s 18720 & 18731
PATCH 1/1 fix c/s 18720 & 18731
Entirely removing the tail of free_page_type() wasn't correct - the type reference must still be dropped for partial pages.
Admittedly, I'm not sure the flush time stamp update is also needed here, but it seems safer to also copy it from free_page_type()'s former tail.
xen/arch/x86/domain.c +11 -0
@@ -42,6 +42,7 @@#include <asm/mpspec.h> #include <asm/ldt.h> #include <asm/hypercall.h> +#include <asm/shadow.h> #include <asm/hvm/hvm.h> #include <asm/hvm/support.h> #include <asm/debugreg.h>
@@ -1687,6 +1688,16 @@ static int relinquish_memory( {if (free_page_type (page, x,0 ) !=0 )BUG (); + +if ( !(shadow_mode_enabled (d) && + (page->count_info & PGC_page_table)) ) + page->tlbflush_timestamp =tlbflush_current_time (); + +if ( x & PGT_partial ) + { +wmb (); + page->u.inuse.type_info--; + }break ; } }
Okay. This is simply because PGT_partial holds a type reference?
The patch can be much simplified because the tlbflush_timestamp is not required (this domain will never run again) and because shadow mode has already been torn down. I'll simplify and apply.
-- Keir
Quoted 46 lines · Jan Beulich
Entirely removing the tail of
free_page_type()wasn't correct - the type reference must still be dropped for partial pages.Admittedly, I'm not sure the flush time stamp update is also needed here, but it seems safer to also copy it from free_page_type()'s former tail.
Signed-off-by Jan Beulich <[email protected]>Index:
2008-10-27/xen/arch/x86/domain.c
===================================================================xen/arch/x86/domain.c 2008-10-28 15:31:15.000000000 +0100 renamed from xen/arch/x86/domain.c 2008-10-28 15:30:37.000000000 +0100 +11
-0@@ -42,6 +42,7 @@ #include <asm/mpspec.h> #include <asm/ldt.h> #include <asm/hypercall.h> +#include <asm/shadow.h> #include <asm/hvm/hvm.h> #include <asm/hvm/support.h> #include <asm/debugreg.h>@@ -1687,6 +1688,16 @@ static int relinquish_memory( { if ( free_page_type(page, x, 0) != 0 ) BUG(); + + if ( !(shadow_mode_enabled(d) && + (page->count_info & PGC_page_table)) ) + page->tlbflush_timestamp = tlbflush_current_time(); + + if ( x & PGT_partial ) + { + wmb(); + page->u.inuse.type_info--; + } break; } }_______________________________________________
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Quoted 2 lines
Quoted 1 line
Quoted 1 line
Keir Fraser <[email protected]> 29.10.08 12:55 >>>
Okay. This is simply because
PGT_partialholds a type reference?
Yes.
Quoted 3 lines
The patch can be much simplified because the
tlbflush_timestampis not required (this domain will never run again) and because shadow mode has already been torn down. I'll simplify and apply.
Understood.
Thanks, Jan