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>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index cac328b..2bb1f2f 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -743,6 +743,24 @@
if (mem->slot >= kvm->nmemslots)
kvm->nmemslots = mem->slot + 1;
+ if (!kvm->n_requested_mmu_pages) {
+ unsigned int n_pages;
+
+ if (npages) {
+ n_pages = npages * KVM_PERMILLE_MMU_PAGES / 1000;
+ kvm_mmu_change_mmu_pages(kvm, kvm->n_alloc_mmu_pages +
+ n_pages);
+ } else {
+ unsigned int nr_mmu_pages;
+
+ n_pages = old.npages * KVM_PERMILLE_MMU_PAGES / 1000;
+ nr_mmu_pages = kvm->n_alloc_mmu_pages - n_pages;
+ nr_mmu_pages = max(nr_mmu_pages,
+ (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
+ kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+ }
+ }
+
*memslot = new;
kvm_mmu_slot_remove_write_access(kvm, mem->slot);
@@ -760,6 +778,26 @@
return r;
}
+static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
+ u32 kvm_nr_mmu_pages)
+{
+ if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
+ return -EINVAL;
+
+ mutex_lock(&kvm->lock);
+
+ kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
+ kvm->n_requested_mmu_pages = kvm_nr_mmu_pages;
+
+ mutex_unlock(&kvm->lock);
+ return 0;
+}
+
+static int kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm)
+{
+ return kvm->n_alloc_mmu_pages;
+}
+
/*
* Get (and clear) the dirty memory log for a memory slot.
*/
@@ -3071,6 +3109,14 @@
goto out;
break;
}
+ case KVM_SET_NR_MMU_PAGES:
+ r = kvm_vm_ioctl_set_nr_mmu_pages(kvm, arg);
+ if (r)
+ goto out;
+ break;
+ case KVM_GET_NR_MMU_PAGES:
+ r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
+ break;
case KVM_GET_DIRTY_LOG: {
struct kvm_dirty_log log;
@@ -3278,6 +3324,7 @@
switch (ext) {
case KVM_CAP_IRQCHIP:
case KVM_CAP_HLT:
+ case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
r = 1;
break;
default: