diff options
| author | Izik Eidus <izike@qumranet.com> | 2007-10-02 18:52:55 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-01-30 17:52:50 +0200 |
| commit | 82ce2c96831f049a37118733ced5c8f7c8848102 (patch) | |
| tree | 609fed010ebbb1ced6f0f24698148e69a72da5fd /drivers/kvm/mmu.c | |
| parent | 195aefde9cc2cee38dd54ef92a866721fba4413e (diff) | |
KVM: Allow dynamic allocation of the mmu shadow cache size
The user is now able to set how many mmu pages will be allocated to the guest.
Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
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 72757db15065..6cda1feb9a95 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 |