Am 09.01.22 um 19:01 schrieb Michael S. Tsirkin:
On Sun, Jan 09, 2022 at 06:52:28PM +0100, Volker Rümelin wrote:
Am 09.01.22 um 17:11 schrieb Michael S. Tsirkin:
On Sun, Jan 09, 2022 at 07:17:30AM +0100, Volker Rümelin wrote:
Hi,
From: Cindy Lu <l...@redhat.com>
Add support for configure interrupt, The process is used kvm_irqfd_assign
to set the gsi to kernel. When the configure notifier was signal by
host, qemu will inject a msix interrupt to guest
Signed-off-by: Cindy Lu <l...@redhat.com>
Message-Id: <20211104164827.21911-11-l...@redhat.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
hw/virtio/virtio-pci.h | 4 +-
hw/virtio/virtio-pci.c | 92 ++++++++++++++++++++++++++++++++++++------
2 files changed, 83 insertions(+), 13 deletions(-)
Since this commit I see the following warnings.
With -drive
if=virtio,id=disk1,file=/srv/cdimg/Linux/images/opensuse.qcow2,discard=unmap
qemu-system-x86_64: virtio-blk failed to set guest notifier (-16), ensure
-accel kvm is set.
qemu-system-x86_64: virtio_bus_start_ioeventfd: failed. Fallback to
userspace (slower).
With libvirt
<controller type='pci' index='1' model='pcie-root-port'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x1c'
function='0'
multifunction='on'/>
</controller>
<controller type='pci' index='2' model='pcie-root-port'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x1c'
function='1'/>
</controller>
<controller type='scsi' index='0' model='virtio-scsi'>
<driver queues='4'/>
<address type='pci' domain='0x0000' bus='0x01' slot='0x00'
function='0'/>
</controller>
<disk type='block' device='disk'>
<driver name='qemu' type='raw' cache='none' discard='unmap'
io='io_uring'/>
<source dev='/dev/vgtmp/lnxpowerm1'/>
<target dev='sda' bus='scsi'/>
<address type='drive' controller='0' bus='0' unit='0'/>
<boot order='1'/>
</disk>
2022-01-08T17:45:26.911491Z qemu-system-x86_64: virtio-scsi: Failed to set
guest notifiers (-16), ensure -accel kvm is set.
2022-01-08T17:45:26.911505Z qemu-system-x86_64: virtio_bus_start_ioeventfd:
failed. Fallback to userspace (slower).
The messages appear around the time the Linux guest initializes the drivers.
With best regards,
Volker
I guess it's a host that has an oldish kernel?
It's an openSUSE 5.3.18 frankenstein kernel.
Does the following help?
No.
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 98fb5493ae..b77cd69f97 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1130,15 +1130,15 @@ static int virtio_pci_set_guest_notifiers(DeviceState
*d, int nvqs, bool assign)
proxy->vector_irqfd =
g_malloc0(sizeof(*proxy->vector_irqfd) *
msix_nr_vectors_allocated(&proxy->pci_dev));
+ r = kvm_virtio_pci_vector_config_use(proxy);
+ if (r < 0) {
+ goto config_error;
+ }
r = kvm_virtio_pci_vector_use(proxy, nvqs);
if (r < 0) {
goto config_assign_error;
}
}
- r = kvm_virtio_pci_vector_config_use(proxy);
- if (r < 0) {
- goto config_error;
- }
r = msix_set_vector_notifiers(&proxy->pci_dev,
virtio_pci_vector_unmask,
virtio_pci_vector_mask,
virtio_pci_vector_poll);
With and without this patch msix_set_vector_notifiers() returns -16.
EBUSY
strace? did a syscall return this?
I hope I got that right. I used
strace ./qemu-system-x86_64 ... 2>strace.txt
There is no EBUSY in strace.txt.
I will sprinkle a few fprintfs to find the first function returning -16.
@@ -1155,7 +1155,9 @@ notifiers_error:
kvm_virtio_pci_vector_release(proxy, nvqs);
}
config_error:
- kvm_virtio_pci_vector_config_release(proxy);
+ if (with_irqfd) {
+ kvm_virtio_pci_vector_config_release(proxy);
+ }
config_assign_error:
virtio_pci_set_guest_notifier(d, VIRTIO_CONFIG_IRQ_IDX, !assign,
with_irqfd);
