提交 82ce2c96 编写于 作者: I Izik Eidus 提交者: Avi Kivity

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: NIzik Eidus <izike@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
上级 195aefde
......@@ -40,6 +40,8 @@
#define KVM_MAX_VCPUS 4
#define KVM_ALIAS_SLOTS 4
#define KVM_MEMORY_SLOTS 8
#define KVM_PERMILLE_MMU_PAGES 20
#define KVM_MIN_ALLOC_MMU_PAGES 64
#define KVM_NUM_MMU_PAGES 1024
#define KVM_MIN_FREE_MMU_PAGES 5
#define KVM_REFILL_PAGES 25
......@@ -418,7 +420,9 @@ struct kvm {
* Hash table of struct kvm_mmu_page.
*/
struct list_head active_mmu_pages;
int n_free_mmu_pages;
unsigned int n_free_mmu_pages;
unsigned int n_requested_mmu_pages;
unsigned int n_alloc_mmu_pages;
struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES];
struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
unsigned long rmap_overflow;
......@@ -547,6 +551,7 @@ void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte);
int kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot);
void kvm_mmu_zap_all(struct kvm *kvm);
void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages);
hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa);
#define HPA_MSB ((sizeof(hpa_t) * 8) - 1)
......
......@@ -743,6 +743,24 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
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 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
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 @@ static long kvm_vm_ioctl(struct file *filp,
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 @@ static long kvm_dev_ioctl(struct file *filp,
switch (ext) {
case KVM_CAP_IRQCHIP:
case KVM_CAP_HLT:
case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
r = 1;
break;
default:
......
......@@ -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
......
......@@ -347,11 +347,14 @@ struct kvm_signal_mask {
*/
#define KVM_CAP_IRQCHIP 0
#define KVM_CAP_HLT 1
#define KVM_CAP_MMU_SHADOW_CACHE_CONTROL 2
/*
* ioctls for VM fds
*/
#define KVM_SET_MEMORY_REGION _IOW(KVMIO, 0x40, struct kvm_memory_region)
#define KVM_SET_NR_MMU_PAGES _IO(KVMIO, 0x44)
#define KVM_GET_NR_MMU_PAGES _IO(KVMIO, 0x45)
/*
* KVM_CREATE_VCPU receives as a parameter the vcpu slot, and returns
* a vcpu fd.
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册