From 8672b7217a234c41d425a63b171af809e1169842 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 2 Aug 2010 16:14:04 +0800 Subject: [PATCH] KVM: MMU: move bits lost judgement into a separate function Introduce spte_has_volatile_bits() function to judge whether spte bits will miss, it's more readable and can help us to cleanup code later Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e430a38..c07b9a2 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -299,6 +299,20 @@ static u64 __xchg_spte(u64 *sptep, u64 new_spte) #endif } +static bool spte_has_volatile_bits(u64 spte) +{ + if (!shadow_accessed_mask) + return false; + + if (!is_shadow_present_pte(spte)) + return false; + + if (spte & shadow_accessed_mask) + return false; + + return true; +} + static void update_spte(u64 *sptep, u64 new_spte) { u64 old_spte; @@ -679,14 +693,14 @@ static void set_spte_track_bits(u64 *sptep, u64 new_spte) pfn_t pfn; u64 old_spte = *sptep; - if (!shadow_accessed_mask || !is_shadow_present_pte(old_spte) || - old_spte & shadow_accessed_mask) { + if (!spte_has_volatile_bits(old_spte)) __set_spte(sptep, new_spte); - } else + else old_spte = __xchg_spte(sptep, new_spte); if (!is_rmap_spte(old_spte)) return; + pfn = spte_to_pfn(old_spte); if (!shadow_accessed_mask || old_spte & shadow_accessed_mask) kvm_set_pfn_accessed(pfn); -- 2.7.4