| Message ID | 1369435455-15885-1-git-send-email-akong@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, May 25, 2013 at 06:44:15AM +0800, Amos Kong wrote: > 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> > --- > include/linux/kvm_host.h | 3 ++- > virt/kvm/eventfd.c | 2 ++ > virt/kvm/kvm_main.c | 3 ++- > 3 files changed, 6 insertions(+), 2 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, May 25, 2013 at 06:44:15AM +0800, Amos Kong wrote: > 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> Applied, thanks. > --- > include/linux/kvm_host.h | 3 ++- > virt/kvm/eventfd.c | 2 ++ > 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 f0eea07..ef261ab 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -144,7 +144,8 @@ 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 64ee720..1550637 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 302681c..c6d9baf 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) * > -- > 1.8.1.4 -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f0eea07..ef261ab 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -144,7 +144,8 @@ 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 64ee720..1550637 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 302681c..c6d9baf 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) *
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> --- include/linux/kvm_host.h | 3 ++- virt/kvm/eventfd.c | 2 ++ virt/kvm/kvm_main.c | 3 ++- 3 files changed, 6 insertions(+), 2 deletions(-)