[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-4.0-testing] x86 shadow: reset up-pointers on all l3s when l3s stop being pinnable.
# HG changeset patch # User Keir Fraser <keir@xxxxxxx> # Date 1286028781 -3600 # Node ID 7c68264f359d419361d8df0b735b109d72e7b622 # Parent 63b7e7766f2efa82c0510fcb686f101da69b4f1d x86 shadow: reset up-pointers on all l3s when l3s stop being pinnable. Walking the pinned-shadows list isn't enough: there could be an unpinned (but still shadowed) l3 somewhere and if we later try to unshadow it it'll have an up-pointer of PAGE_LIST_NULL:PAGE_LIST_NULL. Signed-off-by: Tim Deegan <Tim.Deegan@xxxxxxxxxx> xen-unstable changeset: 22224:a4016a257672 xen-unstable date: Sat Oct 02 15:05:50 2010 +0100 --- xen/arch/x86/mm/shadow/common.c | 41 +++++++++++++++++++++++++++++++++++++++ xen/arch/x86/mm/shadow/multi.c | 1 xen/arch/x86/mm/shadow/private.h | 6 +++++ 3 files changed, 48 insertions(+) diff -r 63b7e7766f2e -r 7c68264f359d xen/arch/x86/mm/shadow/common.c --- a/xen/arch/x86/mm/shadow/common.c Sat Oct 02 15:10:53 2010 +0100 +++ b/xen/arch/x86/mm/shadow/common.c Sat Oct 02 15:13:01 2010 +0100 @@ -2871,6 +2871,47 @@ sh_remove_all_shadows_and_parents(struct /**************************************************************************/ +/* Reset the up-pointers of every L3 shadow to 0. + * This is called when l3 shadows stop being pinnable, to clear out all + * the list-head bits so the up-pointer field is properly inititalised. */ +static int sh_clear_up_pointer(struct vcpu *v, mfn_t smfn, mfn_t unused) +{ + mfn_to_page(smfn)->up = 0; + return 0; +} + +void sh_reset_l3_up_pointers(struct vcpu *v) +{ + static hash_callback_t callbacks[SH_type_unused] = { + NULL, /* none */ + NULL, /* l1_32 */ + NULL, /* fl1_32 */ + NULL, /* l2_32 */ + NULL, /* l1_pae */ + NULL, /* fl1_pae */ + NULL, /* l2_pae */ + NULL, /* l2h_pae */ + NULL, /* l1_64 */ + NULL, /* fl1_64 */ + NULL, /* l2_64 */ + NULL, /* l2h_64 */ +#if CONFIG_PAGING_LEVELS >= 4 + sh_clear_up_pointer, /* l3_64 */ +#else + NULL, /* l3_64 */ +#endif + NULL, /* l4_64 */ + NULL, /* p2m */ + NULL /* unused */ + }; + static unsigned int callback_mask = 1 << SH_type_l3_64_shadow; + + hash_foreach(v, callback_mask, callbacks, _mfn(INVALID_MFN)); +} + + +/**************************************************************************/ + static void sh_update_paging_modes(struct vcpu *v) { struct domain *d = v->domain; diff -r 63b7e7766f2e -r 7c68264f359d xen/arch/x86/mm/shadow/multi.c --- a/xen/arch/x86/mm/shadow/multi.c Sat Oct 02 15:10:53 2010 +0100 +++ b/xen/arch/x86/mm/shadow/multi.c Sat Oct 02 15:13:01 2010 +0100 @@ -1613,6 +1613,7 @@ sh_make_shadow(struct vcpu *v, mfn_t gmf sh_unpin(v, page_to_mfn(sp)); } v->domain->arch.paging.shadow.opt_flags &= ~SHOPT_LINUX_L3_TOPLEVEL; + sh_reset_l3_up_pointers(v); } } #endif diff -r 63b7e7766f2e -r 7c68264f359d xen/arch/x86/mm/shadow/private.h --- a/xen/arch/x86/mm/shadow/private.h Sat Oct 02 15:10:53 2010 +0100 +++ b/xen/arch/x86/mm/shadow/private.h Sat Oct 02 15:13:01 2010 +0100 @@ -464,6 +464,12 @@ mfn_t oos_snapshot_lookup(struct vcpu *v #endif /* (SHADOW_OPTIMIZATIONS & SHOPT_OUT_OF_SYNC) */ + +/* Reset the up-pointers of every L3 shadow to 0. + * This is called when l3 shadows stop being pinnable, to clear out all + * the list-head bits so the up-pointer field is properly inititalised. */ +void sh_reset_l3_up_pointers(struct vcpu *v); + /****************************************************************************** * Flags used in the return value of the shadow_set_lXe() functions... */ _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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