From ebcba577682691dd82b82e46489316e3ca8ecdf3 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Tue, 25 Apr 2017 13:00:17 +0100 Subject: [PATCH] x86/mm: make free_perdomain_mappings() idempotent Signed-off-by: Wei Liu Reviewed-by: Andrew Cooper Acked-by: George Dunlap --- xen/arch/x86/mm.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 77b0af1f9e..411eed0d0a 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -6514,9 +6514,14 @@ void destroy_perdomain_mapping(struct domain *d, unsigned long va, void free_perdomain_mappings(struct domain *d) { - l3_pgentry_t *l3tab = __map_domain_page(d->arch.perdomain_l3_pg); + l3_pgentry_t *l3tab; unsigned int i; + if ( !d->arch.perdomain_l3_pg ) + return; + + l3tab = __map_domain_page(d->arch.perdomain_l3_pg); + for ( i = 0; i < PERDOMAIN_SLOTS; ++i) if ( l3e_get_flags(l3tab[i]) & _PAGE_PRESENT ) { @@ -6555,6 +6560,7 @@ void free_perdomain_mappings(struct domain *d) unmap_domain_page(l3tab); free_domheap_page(d->arch.perdomain_l3_pg); + d->arch.perdomain_l3_pg = NULL; } #ifdef MEMORY_GUARD -- 2.30.2