* [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd
@ 2013-05-22 4:57 Amos Kong
2013-05-22 9:32 ` Stefan Hajnoczi
2013-06-03 9:27 ` Gleb Natapov
0 siblings, 2 replies; 6+ messages in thread
From: Amos Kong @ 2013-05-22 4:57 UTC (permalink / raw)
To: gleb; +Cc: qemu-devel, kvm
I try to hotplug 28 * 8 multiple-function devices to guest with
old host kernel, ioeventfds in host kernel will be exhausted, then
qemu fails to allocate ioeventfds for blk/nic devices.
It's better to add detail error here.
Signed-off-by: Amos Kong <akong@redhat.com>
---
kvm-all.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/kvm-all.c b/kvm-all.c
index 8222729..3d5f7b7 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -813,6 +813,8 @@ static void kvm_mem_ioeventfd_add(MemoryListener *listener,
r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
data, true, section->size, match_data);
if (r < 0) {
+ fprintf(stderr, "%s: error adding ioeventfd: %s\n",
+ __func__, strerror(-r));
abort();
}
}
@@ -843,6 +845,8 @@ static void kvm_io_ioeventfd_add(MemoryListener *listener,
r = kvm_set_ioeventfd_pio(fd, section->offset_within_address_space,
data, true, section->size, match_data);
if (r < 0) {
+ fprintf(stderr, "%s: error adding ioeventfd: %s\n",
+ __func__, strerror(-r));
abort();
}
}
--
1.7.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd
2013-05-22 4:57 [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd Amos Kong
@ 2013-05-22 9:32 ` Stefan Hajnoczi
2013-05-22 13:48 ` Amos Kong
2013-06-03 9:27 ` Gleb Natapov
1 sibling, 1 reply; 6+ messages in thread
From: Stefan Hajnoczi @ 2013-05-22 9:32 UTC (permalink / raw)
To: Amos Kong; +Cc: kvm, gleb, qemu-devel
On Wed, May 22, 2013 at 12:57:35PM +0800, Amos Kong wrote:
> I try to hotplug 28 * 8 multiple-function devices to guest with
> old host kernel, ioeventfds in host kernel will be exhausted, then
> qemu fails to allocate ioeventfds for blk/nic devices.
>
> It's better to add detail error here.
>
> Signed-off-by: Amos Kong <akong@redhat.com>
> ---
> kvm-all.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
It would be nice to make kvm bus scalable so that the hardcoded
in-kernel I/O device limit can be lifted.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd
2013-05-22 9:32 ` Stefan Hajnoczi
@ 2013-05-22 13:48 ` Amos Kong
2013-05-23 7:46 ` Stefan Hajnoczi
0 siblings, 1 reply; 6+ messages in thread
From: Amos Kong @ 2013-05-22 13:48 UTC (permalink / raw)
To: Stefan Hajnoczi; +Cc: kvm, gleb, qemu-devel
On Wed, May 22, 2013 at 11:32:27AM +0200, Stefan Hajnoczi wrote:
> On Wed, May 22, 2013 at 12:57:35PM +0800, Amos Kong wrote:
> > I try to hotplug 28 * 8 multiple-function devices to guest with
> > old host kernel, ioeventfds in host kernel will be exhausted, then
> > qemu fails to allocate ioeventfds for blk/nic devices.
> >
> > It's better to add detail error here.
> >
> > Signed-off-by: Amos Kong <akong@redhat.com>
> > ---
> > kvm-all.c | 4 ++++
> > 1 files changed, 4 insertions(+), 0 deletions(-)
>
> It would be nice to make kvm bus scalable so that the hardcoded
> in-kernel I/O device limit can be lifted.
I had increased kernel NR_IOBUS_DEVS to 1000 (a limitation is needed for
security) in last Mar, and make resizing kvm_io_range array dynamical.
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
--
Amos.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd
2013-05-22 13:48 ` Amos Kong
@ 2013-05-23 7:46 ` Stefan Hajnoczi
2013-05-24 9:16 ` Amos Kong
0 siblings, 1 reply; 6+ messages in thread
From: Stefan Hajnoczi @ 2013-05-23 7:46 UTC (permalink / raw)
To: Amos Kong; +Cc: kvm, gleb, qemu-devel
On Wed, May 22, 2013 at 09:48:21PM +0800, Amos Kong wrote:
> On Wed, May 22, 2013 at 11:32:27AM +0200, Stefan Hajnoczi wrote:
> > On Wed, May 22, 2013 at 12:57:35PM +0800, Amos Kong wrote:
> > > I try to hotplug 28 * 8 multiple-function devices to guest with
> > > old host kernel, ioeventfds in host kernel will be exhausted, then
> > > qemu fails to allocate ioeventfds for blk/nic devices.
> > >
> > > It's better to add detail error here.
> > >
> > > Signed-off-by: Amos Kong <akong@redhat.com>
> > > ---
> > > kvm-all.c | 4 ++++
> > > 1 files changed, 4 insertions(+), 0 deletions(-)
> >
> > It would be nice to make kvm bus scalable so that the hardcoded
> > in-kernel I/O device limit can be lifted.
>
> I had increased kernel NR_IOBUS_DEVS to 1000 (a limitation is needed for
> security) in last Mar, and make resizing kvm_io_range array dynamical.
The maximum should not be hardcoded. File descriptor, maximum memory,
etc are all controlled by rlimits. And since ioeventfds are file
descriptors they are already limited by the maximum number of file
descriptors.
Why is there a need to impose a hardcoded limit?
Stefan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd
2013-05-23 7:46 ` Stefan Hajnoczi
@ 2013-05-24 9:16 ` Amos Kong
0 siblings, 0 replies; 6+ messages in thread
From: Amos Kong @ 2013-05-24 9:16 UTC (permalink / raw)
To: Stefan Hajnoczi; +Cc: kvm, gleb, qemu-devel
On Thu, May 23, 2013 at 09:46:07AM +0200, Stefan Hajnoczi wrote:
> On Wed, May 22, 2013 at 09:48:21PM +0800, Amos Kong wrote:
> > On Wed, May 22, 2013 at 11:32:27AM +0200, Stefan Hajnoczi wrote:
> > > On Wed, May 22, 2013 at 12:57:35PM +0800, Amos Kong wrote:
> > > > I try to hotplug 28 * 8 multiple-function devices to guest with
> > > > old host kernel, ioeventfds in host kernel will be exhausted, then
> > > > qemu fails to allocate ioeventfds for blk/nic devices.
> > > >
> > > > It's better to add detail error here.
> > > >
> > > > Signed-off-by: Amos Kong <akong@redhat.com>
> > > > ---
> > > > kvm-all.c | 4 ++++
> > > > 1 files changed, 4 insertions(+), 0 deletions(-)
> > >
> > > It would be nice to make kvm bus scalable so that the hardcoded
> > > in-kernel I/O device limit can be lifted.
> >
> > I had increased kernel NR_IOBUS_DEVS to 1000 (a limitation is needed for
> > security) in last Mar, and make resizing kvm_io_range array dynamical.
>
> The maximum should not be hardcoded. File descriptor, maximum memory,
> etc are all controlled by rlimits. And since ioeventfds are file
> descriptors they are already limited by the maximum number of file
> descriptors.
For implement the dynamically resize the kvm_io_range array,
I re-allocate new array (with new size) and free old array
when the array flexes. The array is only resized when
add/remove ioeventfds. It will not effect the perf.
> Why is there a need to impose a hardcoded limit?
I will send a patch to fix it.
> Stefan
--
Amos.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd
2013-05-22 4:57 [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd Amos Kong
2013-05-22 9:32 ` Stefan Hajnoczi
@ 2013-06-03 9:27 ` Gleb Natapov
1 sibling, 0 replies; 6+ messages in thread
From: Gleb Natapov @ 2013-06-03 9:27 UTC (permalink / raw)
To: Amos Kong; +Cc: qemu-devel, kvm
On Wed, May 22, 2013 at 12:57:35PM +0800, Amos Kong wrote:
> I try to hotplug 28 * 8 multiple-function devices to guest with
> old host kernel, ioeventfds in host kernel will be exhausted, then
> qemu fails to allocate ioeventfds for blk/nic devices.
>
> It's better to add detail error here.
>
Applied, thanks.
> Signed-off-by: Amos Kong <akong@redhat.com>
> ---
> kvm-all.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/kvm-all.c b/kvm-all.c
> index 8222729..3d5f7b7 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -813,6 +813,8 @@ static void kvm_mem_ioeventfd_add(MemoryListener *listener,
> r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
> data, true, section->size, match_data);
> if (r < 0) {
> + fprintf(stderr, "%s: error adding ioeventfd: %s\n",
> + __func__, strerror(-r));
> abort();
> }
> }
> @@ -843,6 +845,8 @@ static void kvm_io_ioeventfd_add(MemoryListener *listener,
> r = kvm_set_ioeventfd_pio(fd, section->offset_within_address_space,
> data, true, section->size, match_data);
> if (r < 0) {
> + fprintf(stderr, "%s: error adding ioeventfd: %s\n",
> + __func__, strerror(-r));
> abort();
> }
> }
> --
> 1.7.1
--
Gleb.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-06-03 9:28 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-05-22 4:57 [Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd Amos Kong
2013-05-22 9:32 ` Stefan Hajnoczi
2013-05-22 13:48 ` Amos Kong
2013-05-23 7:46 ` Stefan Hajnoczi
2013-05-24 9:16 ` Amos Kong
2013-06-03 9:27 ` Gleb Natapov
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).