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authorAmos Kong <akong@redhat.com>2013-05-25 06:44:15 +0800
committerGleb Natapov <gleb@redhat.com>2013-06-04 11:49:38 +0300
commit6ea34c9b78c10289846db0abeebd6b84d5aca084 (patch)
tree23b7139d16f9bf7c0a5ccd306c39d1b66570b61c /virt
parent566af9404bf57267ea4fc29ca6b4628a17ee3ea7 (diff)
downloadlinux-stericsson-6ea34c9b78c10289846db0abeebd6b84d5aca084.tar.gz
kvm: exclude ioeventfd from counting kvm_io_range limit
We can easily reach the 1000 limit by start VM with a couple hundred I/O devices (multifunction=on). The hardcode limit already been adjusted 3 times (6 ~ 200 ~ 300 ~ 1000). In userspace, we already have maximum file descriptor to limit ioeventfd count. But kvm_io_bus devices also are used for pit, pic, ioapic, coalesced_mmio. They couldn't be limited by maximum file descriptor. Currently only ioeventfds take too much kvm_io_bus devices, so just exclude it from counting kvm_io_range limit. Also fixed one indent issue in kvm_host.h Signed-off-by: Amos Kong <akong@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/eventfd.c2
-rw-r--r--virt/kvm/kvm_main.c3
2 files changed, 4 insertions, 1 deletions
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 64ee720b75c7..1550637d1b10 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -753,6 +753,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
if (ret < 0)
goto unlock_fail;
+ kvm->buses[bus_idx]->ioeventfd_count++;
list_add_tail(&p->list, &kvm->ioeventfds);
mutex_unlock(&kvm->slots_lock);
@@ -798,6 +799,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
continue;
kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
+ kvm->buses[bus_idx]->ioeventfd_count--;
ioeventfd_release(p);
ret = 0;
break;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b547a1ceecbc..1580dd4ace4e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2926,7 +2926,8 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
struct kvm_io_bus *new_bus, *bus;
bus = kvm->buses[bus_idx];
- if (bus->dev_count > NR_IOBUS_DEVS - 1)
+ /* exclude ioeventfd which is limited by maximum fd */
+ if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
return -ENOSPC;
new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) *