similar to: [PATCHv5 3/3] virtio_pci: optional MSI-X support

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 +++++++++++++++++++++++++++++++++++++++----

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

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

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 | 209 +++++++++++++++++++++++++++++++++++++------

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 | 209 +++++++++++++++++++++++++++++++++++++------

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

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

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 | 147 ++++++++++++++++++++++++++++++++++++++----- 1 files changed,

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 | 147 ++++++++++++++++++++++++++++++++++++++----- 1 files changed,

Move everything dealing with legacy devices out to virtio_pci_legacy.c. Expose common code APIs in virtio_pci.h Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.h | 133 ++++++++++++ drivers/virtio/virtio_pci.c | 420 ++----------------------------------- drivers/virtio/virtio_pci_legacy.c | 323 ++++++++++++++++++++++++++++ 3 files changed,

Move everything dealing with legacy devices out to virtio_pci_legacy.c. Expose common code APIs in virtio_pci.h Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_pci.h | 133 ++++++++++++ drivers/virtio/virtio_pci.c | 420 ++----------------------------------- drivers/virtio/virtio_pci_legacy.c | 323 ++++++++++++++++++++++++++++ 3 files changed,