Commit a1300716 authored by Amos Kong's avatar Amos Kong Committed by Avi Kivity
Browse files

KVM: resize kvm_io_range array dynamically 



This patch makes the kvm_io_range array can be resized dynamically.

Signed-off-by: default avatarAmos Kong <akong@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 83c52915

include/linux/kvm_host.h

+3 −2
Original line number Diff line number Diff line
@@ -68,10 +68,11 @@ struct kvm_io_range { 
	struct kvm_io_device *dev;

};



#define NR_IOBUS_DEVS 300



struct kvm_io_bus {

	int                   dev_count;

#define NR_IOBUS_DEVS 300

	struct kvm_io_range range[NR_IOBUS_DEVS];

	struct kvm_io_range range[];

};



enum kvm_bus {

virt/kvm/kvm_main.c

+18 −20
Original line number Diff line number Diff line
@@ -2393,9 +2393,6 @@ int kvm_io_bus_sort_cmp(const void *p1, const void *p2) 
int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,

			  gpa_t addr, int len)

{

	if (bus->dev_count == NR_IOBUS_DEVS)

		return -ENOSPC;



	bus->range[bus->dev_count++] = (struct kvm_io_range) {

		.addr = addr,

		.len = len,
@@ -2498,9 +2495,12 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, 
	if (bus->dev_count > NR_IOBUS_DEVS - 1)

		return -ENOSPC;



	new_bus = kmemdup(bus, sizeof(struct kvm_io_bus), GFP_KERNEL);

	new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) *

			  sizeof(struct kvm_io_range)), GFP_KERNEL);

	if (!new_bus)

		return -ENOMEM;

	memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count *

	       sizeof(struct kvm_io_range)));

	kvm_io_bus_insert_dev(new_bus, dev, addr, len);

	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);

	synchronize_srcu_expedited(&kvm->srcu);
@@ -2517,27 +2517,25 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, 
	struct kvm_io_bus *new_bus, *bus;



	bus = kvm->buses[bus_idx];



	new_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL);

	if (!new_bus)

		return -ENOMEM;



	r = -ENOENT;

	for (i = 0; i < new_bus->dev_count; i++)

		if (new_bus->range[i].dev == dev) {

	for (i = 0; i < bus->dev_count; i++)

		if (bus->range[i].dev == dev) {

			r = 0;

			new_bus->dev_count--;

			new_bus->range[i] = new_bus->range[new_bus->dev_count];

			sort(new_bus->range, new_bus->dev_count,

			     sizeof(struct kvm_io_range),

			     kvm_io_bus_sort_cmp, NULL);

			break;

		}



	if (r) {

		kfree(new_bus);

	if (r)

		return r;

	}



	new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) *

			  sizeof(struct kvm_io_range)), GFP_KERNEL);

	if (!new_bus)

		return -ENOMEM;



	memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));

	new_bus->dev_count--;

	memcpy(new_bus->range + i, bus->range + i + 1,

	       (new_bus->dev_count - i) * sizeof(struct kvm_io_range));



	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);

	synchronize_srcu_expedited(&kvm->srcu);