From 3b34170522fa711e955d71b0110cacda96a316b0 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 9 Jun 2016 15:49:16 +0200 Subject: [PATCH] x86/shadow: sh_pagetable_dying() cleanup Don't call shadow_hash_lookup() at all when get_gfn_query_unlocked() didn't return a valid MFN. Also no need for local variables used only once, the more with scopes much wider than their actual use. Signed-off-by: Jan Beulich Acked-by: Tim Deegan --- xen/arch/x86/mm/shadow/multi.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c index 428be374b8..dfe59a2d8c 100644 --- a/xen/arch/x86/mm/shadow/multi.c +++ b/xen/arch/x86/mm/shadow/multi.c @@ -4501,7 +4501,6 @@ static void sh_pagetable_dying(struct vcpu *v, paddr_t gpa) p2m_type_t p2mt; char *gl3pa = NULL; guest_l3e_t *gl3e = NULL; - paddr_t gl2a = 0; unsigned long l3gfn; mfn_t l3mfn; @@ -4528,7 +4527,6 @@ static void sh_pagetable_dying(struct vcpu *v, paddr_t gpa) } for ( i = 0; i < 4; i++ ) { - unsigned long gfn; mfn_t smfn, gmfn; if ( fast_path ) { @@ -4540,10 +4538,11 @@ static void sh_pagetable_dying(struct vcpu *v, paddr_t gpa) else { /* retrieving the l2s */ - gl2a = guest_l3e_get_paddr(gl3e[i]); - gfn = gl2a >> PAGE_SHIFT; - gmfn = get_gfn_query_unlocked(d, gfn, &p2mt); - smfn = shadow_hash_lookup(d, mfn_x(gmfn), SH_type_l2_pae_shadow); + gmfn = get_gfn_query_unlocked(d, gfn_x(guest_l3e_get_gfn(gl3e[i])), + &p2mt); + smfn = unlikely(mfn_x(gmfn) == INVALID_MFN) + ? _mfn(INVALID_MFN) + : shadow_hash_lookup(d, mfn_x(gmfn), SH_type_l2_pae_shadow); } if ( mfn_valid(smfn) ) -- 2.30.2