Commit 00f034a1 authored by Paolo Bonzini's avatar Paolo Bonzini

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: default avatarDavid Matlack <dmatlack@google.com>
Reviewed-by: default avatarXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent fd275235
......@@ -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,
......
......@@ -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;
......
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