diff options
Diffstat (limited to 'drivers/kvm/mmu.c')
| -rw-r--r-- | drivers/kvm/mmu.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index 72757db1506..6cda1feb9a9 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -747,6 +747,40 @@ static void kvm_mmu_zap_page(struct kvm *kvm, kvm_mmu_reset_last_pte_updated(kvm); } +/* + * Changing the number of mmu pages allocated to the vm + * Note: if kvm_nr_mmu_pages is too small, you will get dead lock + */ +void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages) +{ + /* + * If we set the number of mmu pages to be smaller be than the + * number of actived pages , we must to free some mmu pages before we + * change the value + */ + + if ((kvm->n_alloc_mmu_pages - kvm->n_free_mmu_pages) > + kvm_nr_mmu_pages) { + int n_used_mmu_pages = kvm->n_alloc_mmu_pages + - kvm->n_free_mmu_pages; + + while (n_used_mmu_pages > kvm_nr_mmu_pages) { + struct kvm_mmu_page *page; + + page = container_of(kvm->active_mmu_pages.prev, + struct kvm_mmu_page, link); + kvm_mmu_zap_page(kvm, page); + n_used_mmu_pages--; + } + kvm->n_free_mmu_pages = 0; + } + else + kvm->n_free_mmu_pages += kvm_nr_mmu_pages + - kvm->n_alloc_mmu_pages; + + kvm->n_alloc_mmu_pages = kvm_nr_mmu_pages; +} + static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn) { unsigned index; @@ -1297,8 +1331,10 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu) ASSERT(vcpu); - vcpu->kvm->n_free_mmu_pages = KVM_NUM_MMU_PAGES; - + if (vcpu->kvm->n_requested_mmu_pages) + vcpu->kvm->n_free_mmu_pages = vcpu->kvm->n_requested_mmu_pages; + else + vcpu->kvm->n_free_mmu_pages = vcpu->kvm->n_alloc_mmu_pages; /* * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64. * Therefore we need to allocate shadow page tables in the first |