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Commit 3f0d4db7 authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Radim Krčmář
Browse files

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



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: default avatarDenys 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: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent 9034e6e8

arch/x86/kvm/svm.c

+21 −40
Original line number Diff line number Diff line
@@ -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);