Commit 11ec2804 authored by Shaohua Li's avatar Shaohua Li Committed by Avi Kivity
Browse files

KVM: Convert vm lock to a mutex 



This allows the kvm mmu to perform sleepy operations, such as memory
allocation.

Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 15ad7146

drivers/kvm/kvm.h

+1 −1
Original line number Diff line number Diff line
@@ -393,7 +393,7 @@ struct kvm_memory_slot { 
};



struct kvm {

	spinlock_t lock; /* protects everything except vcpus */

	struct mutex lock; /* protects everything except vcpus */

	int naliases;

	struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS];

	int nmemslots;

drivers/kvm/kvm_main.c

+33 −36
Original line number Diff line number Diff line
@@ -363,7 +363,7 @@ static struct kvm *kvm_create_vm(void) 
		return ERR_PTR(-ENOMEM);



	kvm_io_bus_init(&kvm->pio_bus);

	spin_lock_init(&kvm->lock);

	mutex_init(&kvm->lock);

	INIT_LIST_HEAD(&kvm->active_mmu_pages);

	kvm_io_bus_init(&kvm->mmio_bus);

	spin_lock(&kvm_lock);
@@ -489,7 +489,7 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3) 
	struct page *page;

	u64 pdpte[ARRAY_SIZE(vcpu->pdptrs)];



	spin_lock(&vcpu->kvm->lock);

	mutex_lock(&vcpu->kvm->lock);

	page = gfn_to_page(vcpu->kvm, pdpt_gfn);

	if (!page) {

		ret = 0;
@@ -510,7 +510,7 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3) 


	memcpy(vcpu->pdptrs, pdpte, sizeof(vcpu->pdptrs));

out:

	spin_unlock(&vcpu->kvm->lock);

	mutex_unlock(&vcpu->kvm->lock);



	return ret;

}
@@ -570,9 +570,9 @@ void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) 
	kvm_arch_ops->set_cr0(vcpu, cr0);

	vcpu->cr0 = cr0;



	spin_lock(&vcpu->kvm->lock);

	mutex_lock(&vcpu->kvm->lock);

	kvm_mmu_reset_context(vcpu);

	spin_unlock(&vcpu->kvm->lock);

	mutex_unlock(&vcpu->kvm->lock);

	return;

}

EXPORT_SYMBOL_GPL(set_cr0);
@@ -611,9 +611,9 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) 
		return;

	}

	kvm_arch_ops->set_cr4(vcpu, cr4);

	spin_lock(&vcpu->kvm->lock);

	mutex_lock(&vcpu->kvm->lock);

	kvm_mmu_reset_context(vcpu);

	spin_unlock(&vcpu->kvm->lock);

	mutex_unlock(&vcpu->kvm->lock);

}

EXPORT_SYMBOL_GPL(set_cr4);
@@ -650,7 +650,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) 
	}



	vcpu->cr3 = cr3;

	spin_lock(&vcpu->kvm->lock);

	mutex_lock(&vcpu->kvm->lock);

	/*

	 * Does the new cr3 value map to physical memory? (Note, we

	 * catch an invalid cr3 even in real-mode, because it would
@@ -664,7 +664,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) 
		inject_gp(vcpu);

	else

		vcpu->mmu.new_cr3(vcpu);

	spin_unlock(&vcpu->kvm->lock);

	mutex_unlock(&vcpu->kvm->lock);

}

EXPORT_SYMBOL_GPL(set_cr3);
@@ -741,7 +741,7 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, 
		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;



raced:

	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);



	memory_config_version = kvm->memory_config_version;

	new = old = *memslot;
@@ -770,7 +770,7 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, 
	 * Do memory allocations outside lock.  memory_config_version will

	 * detect any races.

	 */

	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);



	/* Deallocate if slot is being removed */

	if (!npages)
@@ -809,10 +809,10 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, 
		memset(new.dirty_bitmap, 0, dirty_bytes);

	}



	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);



	if (memory_config_version != kvm->memory_config_version) {

		spin_unlock(&kvm->lock);

		mutex_unlock(&kvm->lock);

		kvm_free_physmem_slot(&new, &old);

		goto raced;

	}
@@ -830,13 +830,13 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, 
	kvm_mmu_slot_remove_write_access(kvm, mem->slot);

	kvm_flush_remote_tlbs(kvm);



	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);



	kvm_free_physmem_slot(&old, &new);

	return 0;



out_unlock:

	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);

out_free:

	kvm_free_physmem_slot(&new, &old);

out:
@@ -854,14 +854,14 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, 
	int n;

	unsigned long any = 0;



	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);



	/*

	 * Prevent changes to guest memory configuration even while the lock

	 * is not taken.

	 */

	++kvm->busy;

	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);

	r = -EINVAL;

	if (log->slot >= KVM_MEMORY_SLOTS)

		goto out;
@@ -880,18 +880,18 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, 
	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))

		goto out;



	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);

	kvm_mmu_slot_remove_write_access(kvm, log->slot);

	kvm_flush_remote_tlbs(kvm);

	memset(memslot->dirty_bitmap, 0, n);

	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);



	r = 0;



out:

	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);

	--kvm->busy;

	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);

	return r;

}
@@ -921,7 +921,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, 
	    < alias->target_phys_addr)

		goto out;



	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);



	p = &kvm->aliases[alias->slot];

	p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
@@ -935,7 +935,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, 


	kvm_mmu_zap_all(kvm);



	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);



	return 0;
@@ -1900,12 +1900,12 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, 
	vcpu->pio.cur_count = now;



	for (i = 0; i < nr_pages; ++i) {

		spin_lock(&vcpu->kvm->lock);

		mutex_lock(&vcpu->kvm->lock);

		page = gva_to_page(vcpu, address + i * PAGE_SIZE);

		if (page)

			get_page(page);

		vcpu->pio.guest_pages[i] = page;

		spin_unlock(&vcpu->kvm->lock);

		mutex_unlock(&vcpu->kvm->lock);

		if (!page) {

			inject_gp(vcpu);

			free_pio_guest_pages(vcpu);
@@ -2298,13 +2298,13 @@ static int kvm_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, 
	gpa_t gpa;



	vcpu_load(vcpu);

	spin_lock(&vcpu->kvm->lock);

	mutex_lock(&vcpu->kvm->lock);

	gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);

	tr->physical_address = gpa;

	tr->valid = gpa != UNMAPPED_GVA;

	tr->writeable = 1;

	tr->usermode = 0;

	spin_unlock(&vcpu->kvm->lock);

	mutex_unlock(&vcpu->kvm->lock);

	vcpu_put(vcpu);



	return 0;
@@ -2426,14 +2426,14 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n) 
	if (r < 0)

		goto free_vcpu;



	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);

	if (kvm->vcpus[n]) {

		r = -EEXIST;

		spin_unlock(&kvm->lock);

		mutex_unlock(&kvm->lock);

		goto mmu_unload;

	}

	kvm->vcpus[n] = vcpu;

	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);



	/* Now it's all set up, let userspace reach it */

	r = create_vcpu_fd(vcpu);
@@ -2442,9 +2442,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n) 
	return r;



unlink:

	spin_lock(&kvm->lock);

	mutex_lock(&kvm->lock);

	kvm->vcpus[n] = NULL;

	spin_unlock(&kvm->lock);

	mutex_unlock(&kvm->lock);



mmu_unload:

	vcpu_load(vcpu);
@@ -2945,8 +2945,7 @@ static void decache_vcpus_on_cpu(int cpu) 
	int i;



	spin_lock(&kvm_lock);

	list_for_each_entry(vm, &vm_list, vm_list) {

		spin_lock(&vm->lock);

	list_for_each_entry(vm, &vm_list, vm_list)

		for (i = 0; i < KVM_MAX_VCPUS; ++i) {

			vcpu = vm->vcpus[i];

			if (!vcpu)
@@ -2967,8 +2966,6 @@ static void decache_vcpus_on_cpu(int cpu) 
				mutex_unlock(&vcpu->mutex);

			}

		}

		spin_unlock(&vm->lock);

	}

	spin_unlock(&kvm_lock);

}

drivers/kvm/mmu.c

+4 −5
Original line number Diff line number Diff line
@@ -275,10 +275,9 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) 
	r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);

	kvm_mmu_free_some_pages(vcpu);

	if (r < 0) {

		spin_unlock(&vcpu->kvm->lock);

		mutex_unlock(&vcpu->kvm->lock);

		r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);

		spin_lock(&vcpu->kvm->lock);

		kvm_mmu_free_some_pages(vcpu);

		mutex_lock(&vcpu->kvm->lock);

	}

	return r;

}
@@ -1069,7 +1068,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) 
{

	int r;



	spin_lock(&vcpu->kvm->lock);

	mutex_lock(&vcpu->kvm->lock);

	r = mmu_topup_memory_caches(vcpu);

	if (r)

		goto out;
@@ -1077,7 +1076,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) 
	kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);

	kvm_mmu_flush_tlb(vcpu);

out:

	spin_unlock(&vcpu->kvm->lock);

	mutex_unlock(&vcpu->kvm->lock);

	return r;

}

EXPORT_SYMBOL_GPL(kvm_mmu_load);

drivers/kvm/svm.c

+4 −4
Original line number Diff line number Diff line
@@ -941,21 +941,21 @@ static int pf_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	if (is_external_interrupt(exit_int_info))

		push_irq(vcpu, exit_int_info & SVM_EVTINJ_VEC_MASK);



	spin_lock(&vcpu->kvm->lock);

	mutex_lock(&vcpu->kvm->lock);



	fault_address  = svm->vmcb->control.exit_info_2;

	error_code = svm->vmcb->control.exit_info_1;

	r = kvm_mmu_page_fault(vcpu, fault_address, error_code);

	if (r < 0) {

		spin_unlock(&vcpu->kvm->lock);

		mutex_unlock(&vcpu->kvm->lock);

		return r;

	}

	if (!r) {

		spin_unlock(&vcpu->kvm->lock);

		mutex_unlock(&vcpu->kvm->lock);

		return 1;

	}

	er = emulate_instruction(vcpu, kvm_run, fault_address, error_code);

	spin_unlock(&vcpu->kvm->lock);

	mutex_unlock(&vcpu->kvm->lock);



	switch (er) {

	case EMULATE_DONE:

drivers/kvm/vmx.c

+4 −4
Original line number Diff line number Diff line
@@ -1711,19 +1711,19 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	if (is_page_fault(intr_info)) {

		cr2 = vmcs_readl(EXIT_QUALIFICATION);



		spin_lock(&vcpu->kvm->lock);

		mutex_lock(&vcpu->kvm->lock);

		r = kvm_mmu_page_fault(vcpu, cr2, error_code);

		if (r < 0) {

			spin_unlock(&vcpu->kvm->lock);

			mutex_unlock(&vcpu->kvm->lock);

			return r;

		}

		if (!r) {

			spin_unlock(&vcpu->kvm->lock);

			mutex_unlock(&vcpu->kvm->lock);

			return 1;

		}



		er = emulate_instruction(vcpu, kvm_run, cr2, error_code);

		spin_unlock(&vcpu->kvm->lock);

		mutex_unlock(&vcpu->kvm->lock);



		switch (er) {

		case EMULATE_DONE: