From b532dfff95dd775907528737f77472a227c9536a Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Thu, 21 Sep 2017 15:33:04 +0200 Subject: [PATCH] grant-table: simplify get_paged_frame The implementation of get_paged_frame is currently different whether the architecture support sharing memory or paging memory. Both version are extremely similar so it is possible to consolidate in a single implementation. The main difference is the x86 version will allow grant on foreign page when using HVM/PVH whilst Arm does not. At the moment, on x86 foreign pages are only allowed for PVH Dom0. It seems that foreign pages should never be granted so deny them The check for shared/paged memory are now gated with the respective ifdef. Potentially, dummy p2m_is_shared/p2m_is_paging could be implemented for Arm. Lastly remove pointless parenthesis in the code modified. Signed-off-by: Julien Grall Reviewed-by: Wei Liu --- xen/common/grant_table.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c index f48eeff7ad..0f09891f59 100644 --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -338,34 +338,36 @@ static int get_paged_frame(unsigned long gfn, unsigned long *frame, struct domain *rd) { int rc = GNTST_okay; -#if defined(P2M_PAGED_TYPES) || defined(P2M_SHARED_TYPES) p2m_type_t p2mt; + *frame = mfn_x(INVALID_MFN); *page = get_page_from_gfn(rd, gfn, &p2mt, - (readonly) ? P2M_ALLOC : P2M_UNSHARE); - if ( !(*page) ) + readonly ? P2M_ALLOC : P2M_UNSHARE); + if ( !*page ) { - *frame = mfn_x(INVALID_MFN); +#ifdef P2M_SHARED_TYPES if ( p2m_is_shared(p2mt) ) return GNTST_eagain; +#endif +#ifdef P2M_PAGES_TYPES if ( p2m_is_paging(p2mt) ) { p2m_mem_paging_populate(rd, gfn); return GNTST_eagain; } +#endif return GNTST_bad_page; } - *frame = page_to_mfn(*page); -#else - *frame = mfn_x(gfn_to_mfn(rd, _gfn(gfn))); - *page = mfn_valid(_mfn(*frame)) ? mfn_to_page(*frame) : NULL; - if ( (!(*page)) || (!get_page(*page, rd)) ) + + if ( p2m_is_foreign(p2mt) ) { - *frame = mfn_x(INVALID_MFN); + put_page(*page); *page = NULL; - rc = GNTST_bad_page; + + return GNTST_bad_page; } -#endif + + *frame = page_to_mfn(*page); return rc; } -- 2.39.5