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| author | Amos Kong <akong@redhat.com> | 2013-05-25 06:44:15 +0800 |
|---|---|---|
| committer | Gleb Natapov <gleb@redhat.com> | 2013-06-04 11:49:38 +0300 |
| commit | 6ea34c9b78c10289846db0abeebd6b84d5aca084 (patch) | |
| tree | 23b7139d16f9bf7c0a5ccd306c39d1b66570b61c | |
| parent | 566af9404bf57267ea4fc29ca6b4628a17ee3ea7 (diff) | |
| download | linux-6ea34c9b78c10289846db0abeebd6b84d5aca084.tar.bz2 | |
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>
| -rw-r--r-- | include/linux/kvm_host.h | 3 | ||||
| -rw-r--r-- | virt/kvm/eventfd.c | 2 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 3 |
3 files changed, 6 insertions, 2 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index d9a3c30eab2e..e3aae6db276f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -145,7 +145,8 @@ struct kvm_io_range { #define NR_IOBUS_DEVS 1000 struct kvm_io_bus { - int dev_count; + int dev_count; + int ioeventfd_count; struct kvm_io_range range[]; }; 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) * |