diff options
| -rw-r--r-- | xen/arch/x86/mm/p2m.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c index 645c7f90f6..233853b493 100644 --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -438,7 +438,7 @@ p2m_remove_page(struct p2m_domain *p2m, unsigned long gfn, unsigned long mfn, for ( i = 0; i < (1UL << page_order); i++ ) { mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, p2m_query, NULL); - if ( !p2m_is_grant(t) ) + if ( !p2m_is_grant(t) && !p2m_is_shared(t) ) set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY); ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) ); } @@ -500,6 +500,22 @@ guest_physmap_add_entry(struct domain *d, unsigned long gfn, for ( i = 0; i < (1UL << page_order); i++ ) { omfn = p2m->get_entry(p2m, gfn + i, &ot, &a, p2m_query, NULL); +#ifdef __x86_64__ + if ( p2m_is_shared(ot) ) + { + /* Do an unshare to cleanly take care of all corner + * cases. */ + int rc; + rc = mem_sharing_unshare_page(p2m->domain, gfn + i, 0); + if ( rc ) + { + p2m_unlock(p2m); + return rc; + } + omfn = p2m->get_entry(p2m, gfn + i, &ot, &a, p2m_query, NULL); + ASSERT(!p2m_is_shared(ot)); + } +#endif /* __x86_64__ */ if ( p2m_is_grant(ot) ) { /* Really shouldn't be unmapping grant maps this way */ @@ -528,6 +544,14 @@ guest_physmap_add_entry(struct domain *d, unsigned long gfn, /* Then, look for m->p mappings for this range and deal with them */ for ( i = 0; i < (1UL << page_order); i++ ) { + if ( page_get_owner(mfn_to_page(_mfn(mfn + i))) == dom_cow ) + { + /* This is no way to add a shared page to your physmap! */ + gdprintk(XENLOG_ERR, "Adding shared mfn %lx directly to dom %hu " + "physmap not allowed.\n", mfn+i, d->domain_id); + p2m_unlock(p2m); + return -EINVAL; + } if ( page_get_owner(mfn_to_page(_mfn(mfn + i))) != d ) continue; ogfn = mfn_to_gfn(d, _mfn(mfn+i)); |