From 00f034a12fdd81210d58116326d92780aac5c238 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 20 Aug 2014 14:29:21 +0200 Subject: [PATCH] KVM: do not bias the generation number in kvm_current_mmio_generation The next patch will give a meaning (a la seqcount) to the low bit of the generation number. Ensure that it matches between kvm->memslots->generation and kvm_current_mmio_generation(). Cc: stable@vger.kernel.org Reviewed-by: David Matlack Reviewed-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 7 +------ virt/kvm/kvm_main.c | 7 +++++++ 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 9314678..323c3f5 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -236,12 +236,7 @@ static unsigned int get_mmio_spte_generation(u64 spte) static unsigned int kvm_current_mmio_generation(struct kvm *kvm) { - /* - * Init kvm generation close to MMIO_MAX_GEN to easily test the - * code of handling generation number wrap-around. - */ - return (kvm_memslots(kvm)->generation + - MMIO_MAX_GEN - 150) & MMIO_GEN_MASK; + return kvm_memslots(kvm)->generation & MMIO_GEN_MASK; } static void mark_mmio_spte(struct kvm *kvm, u64 *sptep, u64 gfn, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7176929..0bfdb67 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -477,6 +477,13 @@ static struct kvm *kvm_create_vm(unsigned long type) kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!kvm->memslots) goto out_err_no_srcu; + + /* + * Init kvm generation close to the maximum to easily test the + * code of handling generation number wrap-around. + */ + kvm->memslots->generation = -150; + kvm_init_memslots_id(kvm); if (init_srcu_struct(&kvm->srcu)) goto out_err_no_srcu; -- 2.7.4