[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v7 1/7] x86/p2m: Allow p2m_get_page_from_gfn to return shared entries
The owner domain of shared pages is dom_cow, use that for get_page otherwise the function fails to return the correct page under some situations. The check if dom_cow should be used was only performed in a subset of use-cases. Fixing the error and simplifying the existing check since we can't have any shared entries with dom_cow being NULL. Signed-off-by: Tamas K Lengyel <tamas.lengyel@xxxxxxxxx> --- v7: update commit message --- xen/arch/x86/mm/p2m.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c index def13f657b..007fef720d 100644 --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -575,11 +575,12 @@ struct page_info *p2m_get_page_from_gfn( if ( fdom == NULL ) page = NULL; } - else if ( !get_page(page, p2m->domain) && - /* Page could be shared */ - (!dom_cow || !p2m_is_shared(*t) || - !get_page(page, dom_cow)) ) - page = NULL; + else + { + struct domain *d = !p2m_is_shared(*t) ? p2m->domain : dom_cow; + if ( !get_page(page, d) ) + page = NULL; + } } p2m_read_unlock(p2m); @@ -595,8 +596,9 @@ struct page_info *p2m_get_page_from_gfn( mfn = get_gfn_type_access(p2m, gfn_x(gfn), t, a, q, NULL); if ( p2m_is_ram(*t) && mfn_valid(mfn) ) { + struct domain *d = !p2m_is_shared(*t) ? p2m->domain : dom_cow; page = mfn_to_page(mfn); - if ( !get_page(page, p2m->domain) ) + if ( !get_page(page, d) ) page = NULL; } put_gfn(p2m->domain, gfn_x(gfn)); -- 2.20.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |