From ad2cc6b37035dec0066a384ffdacf7238fd2a556 Mon Sep 17 00:00:00 2001 From: "awilliam@xenbuild.aw" Date: Mon, 19 Jun 2006 12:54:34 -0600 Subject: [PATCH] [IA64] add INVALID_MFN check to dom0vp_zap_physmap() guest_physmap_remove_page() should check mfn. Signed-off-by: Isaku Yamahata --- xen/arch/ia64/xen/mm.c | 42 +++++++++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 7 deletions(-) diff --git a/xen/arch/ia64/xen/mm.c b/xen/arch/ia64/xen/mm.c index ac70b9663b..6613e3cd13 100644 --- a/xen/arch/ia64/xen/mm.c +++ b/xen/arch/ia64/xen/mm.c @@ -891,12 +891,11 @@ assign_domain_page_cmpxchg_rel(struct domain* d, unsigned long mpaddr, } static void -zap_domain_page_one(struct domain *d, unsigned long mpaddr) +zap_domain_page_one(struct domain *d, unsigned long mpaddr, unsigned long mfn) { struct mm_struct *mm = &d->arch.mm; volatile pte_t *pte; pte_t old_pte; - unsigned long mfn; struct page_info *page; pte = lookup_noalloc_domain_pte_none(d, mpaddr); @@ -905,9 +904,38 @@ zap_domain_page_one(struct domain *d, unsigned long mpaddr) if (pte_none(*pte)) return; - // update pte - old_pte = ptep_get_and_clear(mm, mpaddr, pte); - mfn = pte_pfn(old_pte); + if (mfn == INVALID_MFN) { + // clear pte + old_pte = ptep_get_and_clear(mm, mpaddr, pte); + mfn = pte_pfn(old_pte); + } else { + unsigned long old_arflags; + pte_t new_pte; + pte_t ret_pte; + + again: + BUG_ON(page_get_owner(mfn_to_page(mfn)) != d); + old_arflags = pte_val(*pte) & ~_PAGE_PPN_MASK; + old_pte = pfn_pte(mfn, __pgprot(old_arflags)); + new_pte = __pte(0); + + // update pte + ret_pte = ptep_cmpxchg_rel(mm, mpaddr, pte, old_pte, new_pte); + if (unlikely(pte_val(old_pte) != pte_val(ret_pte))) { + if (pte_pfn(old_pte) == pte_pfn(ret_pte)) { + goto again; + } + + DPRINTK("%s: old_pte 0x%lx old_arflags 0x%lx mfn 0x%lx " + "ret_pte 0x%lx ret_mfn 0x%lx\n", + __func__, + pte_val(old_pte), old_arflags, mfn, + pte_val(ret_pte), pte_pfn(ret_pte)); + return; + } + BUG_ON(mfn != pte_pfn(ret_pte)); + } + page = mfn_to_page(mfn); BUG_ON((page->count_info & PGC_count_mask) == 0); @@ -931,7 +959,7 @@ dom0vp_zap_physmap(struct domain *d, unsigned long gpfn, return -ENOSYS; } - zap_domain_page_one(d, gpfn << PAGE_SHIFT); + zap_domain_page_one(d, gpfn << PAGE_SHIFT, INVALID_MFN); return 0; } @@ -1193,7 +1221,7 @@ guest_physmap_remove_page(struct domain *d, unsigned long gpfn, unsigned long mfn) { BUG_ON(mfn == 0);//XXX - zap_domain_page_one(d, gpfn << PAGE_SHIFT); + zap_domain_page_one(d, gpfn << PAGE_SHIFT, mfn); } //XXX sledgehammer. -- 2.30.2