similar to: [PATCHv3 2/2] virtio: refactor find_vqs

This refactors find_vqs, making it more readable and robust, and fixing two regressions from 2.6.30: - double free_irq causing BUG_ON on device removal - probe failure when vq can't be assigned to msi-x vector (reported on old host kernels) An older version of this patch was tested by Amit Shah. Reported-by: Amit Shah <amit.shah at redhat.com> Signed-off-by: Michael S. Tsirkin

This refactors find_vqs, making it more readable and robust, and fixing two regressions from 2.6.30: - double free_irq causing BUG_ON on device removal - probe failure when vq can't be assigned to msi-x vector (reported on old host kernels) An older version of this patch was tested by Amit Shah. Reported-by: Amit Shah <amit.shah at redhat.com> Signed-off-by: Michael S. Tsirkin

1) Rename vp_request_vectors to vp_request_msix_vectors, and take non-MSI-X case out to caller. 2) Comment weird pci_enable_msix API 3) Rename vp_find_vq to setup_vq. 4) Fix spaces to tabs 5) Make nvectors calc internal to vp_try_to_find_vqs() 6) Rename vector to msix_vector for more clarity. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Cc: "Michael S. Tsirkin"

1) Rename vp_request_vectors to vp_request_msix_vectors, and take non-MSI-X case out to caller. 2) Comment weird pci_enable_msix API 3) Rename vp_find_vq to setup_vq. 4) Fix spaces to tabs 5) Make nvectors calc internal to vp_try_to_find_vqs() 6) Rename vector to msix_vector for more clarity. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Cc: "Michael S. Tsirkin"

This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.c | 227 +++++++++++++++++++++++++++++++++++++++----

This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.c | 227 +++++++++++++++++++++++++++++++++++++++----

This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.c | 227 +++++++++++++++++++++++++++++++++++++++----

This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.c | 227 +++++++++++++++++++++++++++++++++++++++----

virtio currently fails to find any vqs if the device supports msi-x but fails to assign it to a queue. Turns out, this actually happens for old host kernels which can't allocate a gsi for the vector. As a result guest does not use virtio net. Fix this by retrying with less vectors and finally disabling msi on such failures and falling back on regular interrupts. Reported-by: Amit Shah

virtio currently fails to find any vqs if the device supports msi-x but fails to assign it to a queue. Turns out, this actually happens for old host kernels which can't allocate a gsi for the vector. As a result guest does not use virtio net. Fix this by retrying with less vectors and finally disabling msi on such failures and falling back on regular interrupts. Reported-by: Amit Shah

On (Tue) Jul 21 2009 [19:54:00], Michael S. Tsirkin wrote: > On Fri, Jul 17, 2009 at 06:34:40PM +0530, Amit Shah wrote: > > Hello, > > > > Using recent qemu-kvm userspace with a slightly older kernel module I > > get this when using the virtio-net device: I was getting this with a very recent kernel in the guest with an older host kernel. 2.6.31-rc3 in the guest and

On (Tue) Jul 21 2009 [19:54:00], Michael S. Tsirkin wrote: > On Fri, Jul 17, 2009 at 06:34:40PM +0530, Amit Shah wrote: > > Hello, > > > > Using recent qemu-kvm userspace with a slightly older kernel module I > > get this when using the virtio-net device: I was getting this with a very recent kernel in the guest with an older host kernel. 2.6.31-rc3 in the guest and

msix_user_vectors counted both per-vq and shared/config vectors. This causes BUG_ON when device is removed, as free_vectors tries to free per-vq vectors. Count per-vq vectors separately so they are only freed by del_vq. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.c | 38 +++++++++++++++++++++++--------------- 1 files changed, 23 insertions(+), 15

msix_user_vectors counted both per-vq and shared/config vectors. This causes BUG_ON when device is removed, as free_vectors tries to free per-vq vectors. Count per-vq vectors separately so they are only freed by del_vq. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.c | 38 +++++++++++++++++++++++--------------- 1 files changed, 23 insertions(+), 15

This lets IRQ layer handle dispatching IRQs to separate handlers for the case where we don't have per-VQ MSI-X vectors, and allows us to greatly simplify the code based on the assumption that we always have interrupt vector 0 (legacy INTx or config interrupt for MSI-X) available, and any other interrupt is request/freed throught the VQ, even if the actual interrupt line might be shared in some

This lets IRQ layer handle dispatching IRQs to separate handlers for the case where we don't have per-VQ MSI-X vectors, and allows us to greatly simplify the code based on the assumption that we always have interrupt vector 0 (legacy INTx or config interrupt for MSI-X) available, and any other interrupt is request/freed throught the VQ, even if the actual interrupt line might be shared in some

On Mon, Sep 01, 2014 at 01:41:54PM +0800, Amos Kong wrote: > One VM only has 128 msix interrupt, virtio-config interrupt > has less workload. This patch shares one normal interrupt normal == INT#x? Please don't call it normal. The proper name is "legacy INT#x". So you are trying to use legacy INT#x at the same time with MSI-X? This does not work: the PCI spec says: While

One VM only has 128 msix interrupt, virtio-config interrupt has less workload. This patch shares one normal interrupt for configuration between virtio devices. Signed-off-by: Amos Kong <akong at redhat.com> --- drivers/virtio/virtio_pci.c | 41 ++++++++++++++++------------------------- 1 file changed, 16 insertions(+), 25 deletions(-) diff --git a/drivers/virtio/virtio_pci.c

One VM only has 128 msix interrupt, virtio-config interrupt has less workload. This patch shares one normal interrupt for configuration between virtio devices. Signed-off-by: Amos Kong <akong at redhat.com> --- drivers/virtio/virtio_pci.c | 41 ++++++++++++++++------------------------- 1 file changed, 16 insertions(+), 25 deletions(-) diff --git a/drivers/virtio/virtio_pci.c

Hi all, I'm working on this item in Upstream Networking todolist: | - Sharing config interrupts | Support more devices by sharing a single msi vector | between multiple virtio devices. | (Applies to virtio-blk too). I have this solution here, and only have draft patches of Solution 1 & 2, let's discuss if solution 3 is feasible. * We should not introduce perf regression in