From 6b73a96065e89dc9fa75ba4f78b1aa3a3bbd0470 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Wed, 20 Feb 2013 18:52:02 -0300 Subject: [PATCH] Revert "KVM: MMU: lazily drop large spte" This reverts commit caf6900f2d8aaebe404c976753f6813ccd31d95e. It is causing migration failures, reference https://bugzilla.kernel.org/show_bug.cgi?id=54061. Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/mmu.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 1cda1f332654..4ed3edbe06bd 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1105,7 +1105,8 @@ static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) /* * Write-protect on the specified @sptep, @pt_protect indicates whether - * spte write-protection is caused by protecting shadow page table. + * spte writ-protection is caused by protecting shadow page table. + * @flush indicates whether tlb need be flushed. * * Note: write protection is difference between drity logging and spte * protection: @@ -1114,9 +1115,10 @@ static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) * - for spte protection, the spte can be writable only after unsync-ing * shadow page. * - * Return true if tlb need be flushed. + * Return true if the spte is dropped. */ -static bool spte_write_protect(struct kvm *kvm, u64 *sptep, bool pt_protect) +static bool +spte_write_protect(struct kvm *kvm, u64 *sptep, bool *flush, bool pt_protect) { u64 spte = *sptep; @@ -1126,11 +1128,17 @@ static bool spte_write_protect(struct kvm *kvm, u64 *sptep, bool pt_protect) rmap_printk("rmap_write_protect: spte %p %llx\n", sptep, *sptep); + if (__drop_large_spte(kvm, sptep)) { + *flush |= true; + return true; + } + if (pt_protect) spte &= ~SPTE_MMU_WRITEABLE; spte = spte & ~PT_WRITABLE_MASK; - return mmu_spte_update(sptep, spte); + *flush |= mmu_spte_update(sptep, spte); + return false; } static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, @@ -1142,8 +1150,11 @@ static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, for (sptep = rmap_get_first(*rmapp, &iter); sptep;) { BUG_ON(!(*sptep & PT_PRESENT_MASK)); + if (spte_write_protect(kvm, sptep, &flush, pt_protect)) { + sptep = rmap_get_first(*rmapp, &iter); + continue; + } - flush |= spte_write_protect(kvm, sptep, pt_protect); sptep = rmap_get_next(&iter); } @@ -2581,8 +2592,6 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, break; } - drop_large_spte(vcpu, iterator.sptep); - if (!is_shadow_present_pte(*iterator.sptep)) { u64 base_addr = iterator.addr; -- 2.20.1