@@ -315,7 +315,7 @@ struct kvm_irq_routing_table {};
struct kvm_memslots {
int nmemslots;
u64 generation;
- struct kvm_memory_slot memslots[KVM_MEM_SLOTS_NUM];
+ struct kvm_memory_slot memslots[];
};
struct kvm {
@@ -439,17 +439,6 @@ static int kvm_init_mmu_notifier(struct kvm *kvm)
#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
-static void kvm_init_memslots_id(struct kvm *kvm)
-{
- int i;
- struct kvm_memslots *slots = kvm->memslots;
-
- slots->nmemslots = KVM_MEM_SLOTS_NUM;
-
- for (i = 0; i < kvm->memslots->nmemslots; i++)
- slots->memslots[i].id_to_index = slots->memslots[i].id = i;
-}
-
static struct kvm *kvm_create_vm(unsigned long type)
{
int r, i;
@@ -475,7 +464,6 @@ static struct kvm *kvm_create_vm(unsigned long type)
kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
if (!kvm->memslots)
goto out_err_nosrcu;
- kvm_init_memslots_id(kvm);
if (init_srcu_struct(&kvm->srcu))
goto out_err_nosrcu;
for (i = 0; i < KVM_NR_BUSES; i++) {
@@ -696,6 +684,40 @@ static int check_memory_region_flags(struct kvm_userspace_memory_region *mem)
return 0;
}
+struct kvm_memslots *__kvm_dup_and_grow_memslots(struct kvm_memslots *oldslots,
+ int slot)
+{
+ int nmemslots;
+ struct kvm_memslots *newslots;
+
+ nmemslots = (slot >= oldslots->nmemslots) ?
+ slot + 1 : oldslots->nmemslots;
+
+ newslots = kmalloc(sizeof(struct kvm_memslots) +
+ nmemslots * sizeof(struct kvm_memory_slot), GFP_KERNEL);
+ if (!newslots)
+ return NULL;
+
+ memcpy(newslots, oldslots, sizeof(struct kvm_memslots) +
+ oldslots->nmemslots * sizeof(struct kvm_memory_slot));
+
+ if (nmemslots != oldslots->nmemslots) {
+ int i;
+ memset(&newslots->memslots[oldslots->nmemslots], 0,
+ (nmemslots - oldslots->nmemslots) *
+ sizeof(struct kvm_memory_slot));
+
+ for (i = oldslots->nmemslots; i < nmemslots; i++) {
+ newslots->memslots[i].id_to_index = i;
+ newslots->memslots[i].id = i;
+ }
+
+ newslots->nmemslots = nmemslots;
+ }
+
+ return newslots;
+}
+
/*
* Allocate some memory and give it an address in the guest physical address
* space.
@@ -711,8 +733,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
int r;
gfn_t base_gfn;
unsigned long npages;
- struct kvm_memory_slot *memslot, *slot;
- struct kvm_memory_slot old, new;
+ struct kvm_memory_slot *memslot = NULL, *slot;
+ struct kvm_memory_slot old = {}, new = {};
struct kvm_memslots *slots, *old_memslots;
r = check_memory_region_flags(mem);
@@ -737,7 +759,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
goto out;
- memslot = id_to_memslot(kvm->memslots, mem->slot);
base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
npages = mem->memory_size >> PAGE_SHIFT;
@@ -748,7 +769,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
if (!npages)
mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
- new = old = *memslot;
+ if (mem->slot < kvm->memslots->nmemslots) {
+ memslot = id_to_memslot(kvm->memslots, mem->slot);
+ new = old = *memslot;
+ }
new.id = mem->slot;
new.base_gfn = base_gfn;
@@ -796,8 +820,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
struct kvm_memory_slot *slot;
r = -ENOMEM;
- slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
- GFP_KERNEL);
+ slots = __kvm_dup_and_grow_memslots(kvm->memslots, mem->slot);
if (!slots)
goto out_free;
slot = id_to_memslot(slots, mem->slot);
@@ -832,8 +855,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
kvm_iommu_unmap_pages(kvm, &old);
r = -ENOMEM;
- slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
- GFP_KERNEL);
+ slots = __kvm_dup_and_grow_memslots(kvm->memslots, mem->slot);
if (!slots)
goto out_free;
Start with zero and grow up to KVM_MEM_SLOTS_NUM. A modest guest without device assignment likely uses around 1/4 of the total entries. We don't attempt to shrink the array when slots are released. Both x86 and powerpc still have some statically sized elements elsewhere, but this covers the bulk of the memory used. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- include/linux/kvm_host.h | 2 + virt/kvm/kvm_main.c | 62 +++++++++++++++++++++++++++++++--------------- 2 files changed, 43 insertions(+), 21 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html