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KVM: SVM: delete avic_vm_id_bitmap (2 megabyte static array)

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With lightly tweaked defconfig:

    text    data     bss      dec     hex filename
11259661 5109408 2981888 19350957 12745ad vmlinux.before
11259661 5109408  884736 17253805 10745ad vmlinux.after

Only compile-tested.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This commit is contained in:
Denys Vlasenko 2017-08-11 22:11:58 +02:00 committed by Radim Krčmář
parent 9034e6e895
commit 3f0d4db757
1 changed files with 21 additions and 40 deletions
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61
arch/x86/kvm/svm.c
View File

@ -280,10 +280,6 @@ module_param(avic, int, S_IRUGO);
static int vls = true;
module_param(vls, int, 0444);
/* AVIC VM ID bit masks and lock */
static DECLARE_BITMAP(avic_vm_id_bitmap, AVIC_VM_ID_NR);
static DEFINE_SPINLOCK(avic_vm_id_lock);
static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0);
static void svm_flush_tlb(struct kvm_vcpu *vcpu);
static void svm_complete_interrupts(struct vcpu_svm *svm);
@ -989,6 +985,8 @@ static void disable_nmi_singlestep(struct vcpu_svm *svm)
*/
#define SVM_VM_DATA_HASH_BITS 8
static DEFINE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS);
static u32 next_vm_id = 0;
static bool next_vm_id_wrapped = 0;
static DEFINE_SPINLOCK(svm_vm_data_hash_lock);
/* Note:
@ -1387,34 +1385,6 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu)
return 0;
}
static inline int avic_get_next_vm_id(void)
{
int id;
spin_lock(&avic_vm_id_lock);
/* AVIC VM ID is one-based. */
id = find_next_zero_bit(avic_vm_id_bitmap, AVIC_VM_ID_NR, 1);
if (id <= AVIC_VM_ID_MASK)
__set_bit(id, avic_vm_id_bitmap);
else
id = -EAGAIN;
spin_unlock(&avic_vm_id_lock);
return id;
}
static inline int avic_free_vm_id(int id)
{
if (id <= 0 || id > AVIC_VM_ID_MASK)
return -EINVAL;
spin_lock(&avic_vm_id_lock);
__clear_bit(id, avic_vm_id_bitmap);
spin_unlock(&avic_vm_id_lock);
return 0;
}
static void avic_vm_destroy(struct kvm *kvm)
{
unsigned long flags;
@ -1423,8 +1393,6 @@ static void avic_vm_destroy(struct kvm *kvm)
if (!avic)
return;
avic_free_vm_id(vm_data->avic_vm_id);
if (vm_data->avic_logical_id_table_page)
__free_page(vm_data->avic_logical_id_table_page);
if (vm_data->avic_physical_id_table_page)
@ -1438,19 +1406,16 @@ static void avic_vm_destroy(struct kvm *kvm)
static int avic_vm_init(struct kvm *kvm)
{
unsigned long flags;
int vm_id, err = -ENOMEM;
int err = -ENOMEM;
struct kvm_arch *vm_data = &kvm->arch;
struct page *p_page;
struct page *l_page;
struct kvm_arch *ka;
u32 vm_id;
if (!avic)
return 0;
vm_id = avic_get_next_vm_id();
if (vm_id < 0)
return vm_id;
vm_data->avic_vm_id = (u32)vm_id;
/* Allocating physical APIC ID table (4KB) */
p_page = alloc_page(GFP_KERNEL);
if (!p_page)
@ -1468,6 +1433,22 @@ static int avic_vm_init(struct kvm *kvm)
clear_page(page_address(l_page));
spin_lock_irqsave(&svm_vm_data_hash_lock, flags);
again:
vm_id = next_vm_id = (next_vm_id + 1) & AVIC_VM_ID_MASK;
if (vm_id == 0) { /* id is 1-based, zero is not okay */
next_vm_id_wrapped = 1;
goto again;
}
/* Is it still in use? Only possible if wrapped at least once */
if (next_vm_id_wrapped) {
hash_for_each_possible(svm_vm_data_hash, ka, hnode, vm_id) {
struct kvm *k2 = container_of(ka, struct kvm, arch);
struct kvm_arch *vd2 = &k2->arch;
if (vd2->avic_vm_id == vm_id)
goto again;
}
}
vm_data->avic_vm_id = vm_id;
hash_add(svm_vm_data_hash, &vm_data->hnode, vm_data->avic_vm_id);
spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);