similar to: RFC: sharing config interrupt between virtio devices for saving MSI

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

On Mon, Sep 01, 2014 at 09:37:30AM +0300, Michael S. Tsirkin wrote: > Hi Michael, > 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 Thanks for your quick reply. > normal == INT#x? Please don't call it normal. The proper name is >

On Mon, Sep 01, 2014 at 09:37:30AM +0300, Michael S. Tsirkin wrote: > Hi Michael, > 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 Thanks for your quick reply. > normal == INT#x? Please don't call it normal. The proper name is >

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

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

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

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"

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

We don't really need struct virtio_pci_vq_info, as most field in there are redundant: - the vq backpointer is not strictly neede to start with - the entry in the vqs list is not needed - the generic virtqueue already has list, we only need to check if it has a callback to get the same semantics - we can use a simple array to look up the MSI-X vec if needed. - That simple array now

We don't really need struct virtio_pci_vq_info, as most field in there are redundant: - the vq backpointer is not strictly neede to start with - the entry in the vqs list is not needed - the generic virtqueue already has list, we only need to check if it has a callback to get the same semantics - we can use a simple array to look up the MSI-X vec if needed. - That simple array now

On Tue, Feb 07, 2017 at 03:17:02PM +0800, Jason Wang wrote: > The check is still there. Meh, I could swear I fixed it up. Here is an updated version: --- >From bf5e3b7fd272aea32388570503f00d0ab592fc2a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig <hch at lst.de> Date: Wed, 25 Jan 2017 13:40:21 +0100 Subject: virtio_pci: remove struct virtio_pci_vq_info We don't really need

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