Hello, any feedback on this patch, after a brief email exchange Anthony deferred to Peter.
Lack of improper host features handling lowers 1g & 10g performance substantially on arm-kvm compared to xeon. We would like to have this fixed so we don't have to patch every new release of qemu, especially virtio stuff. - Mario On 02/14/2014 03:49 PM, Peter Maydell wrote: > CCing the virtio maintainers. > > thanks > -- PMM > > On 13 February 2014 21:13, Mario Smarduch <m.smard...@samsung.com> wrote: >> virtio: set virtio-net/virtio-mmio host features >> >> Patch sets 'virtio-net/virtio-mmio' host features to enable network >> features based on peer capabilities. Currently host features turn >> of all features by default. >> >> Signed-off-by: Mario Smarduch <m.smard...@samsung.com> >> --- >> hw/virtio/virtio-mmio.c | 29 +++++++++++++++++++++++++++++ >> 1 file changed, 29 insertions(+) >> >> diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c >> index 8829eb0..1d940b7 100644 >> --- a/hw/virtio/virtio-mmio.c >> +++ b/hw/virtio/virtio-mmio.c >> @@ -23,6 +23,7 @@ >> #include "hw/virtio/virtio.h" >> #include "qemu/host-utils.h" >> #include "hw/virtio/virtio-bus.h" >> +#include "hw/virtio/virtio-net.h" >> >> /* #define DEBUG_VIRTIO_MMIO */ >> >> @@ -92,6 +93,12 @@ typedef struct { >> static void virtio_mmio_bus_new(VirtioBusState *bus, size_t bus_size, >> VirtIOMMIOProxy *dev); >> >> +/* all possible virtio-net features supported */ >> +static Property virtio_mmio_net_properties[] = { >> + DEFINE_VIRTIO_NET_FEATURES(VirtIOMMIOProxy, host_features), >> + DEFINE_PROP_END_OF_LIST(), >> +}; >> + >> static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size) >> { >> VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque; >> @@ -347,11 +354,33 @@ static void virtio_mmio_reset(DeviceState *d) >> >> /* virtio-mmio device */ >> >> +/* Walk virtio-net possible supported features and set host_features, this >> + * should be done earlier when the object is instantiated but at that point >> + * you don't know what type of device will be plugged in. >> + */ >> +static void virtio_mmio_set_net_features(Property *prop, uint32_t *features) >> +{ >> + for (; prop && prop->name; prop++) { >> + if (prop->defval == true) { >> + *features |= (1 << prop->bitnr); >> + } else { >> + *features &= ~(1 << prop->bitnr); >> + } >> + } >> +} >> + >> /* This is called by virtio-bus just after the device is plugged. */ >> static void virtio_mmio_device_plugged(DeviceState *opaque) >> { >> VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); >> + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); >> + Object *obj = OBJECT(vdev); >> >> + /* set host features only for virtio-net */ >> + if (object_dynamic_cast(obj, TYPE_VIRTIO_NET)) { >> + virtio_mmio_set_net_features(virtio_mmio_net_properties, >> + >> &proxy->host_features); >> + } >> proxy->host_features |= (0x1 << VIRTIO_F_NOTIFY_ON_EMPTY); >> proxy->host_features = virtio_bus_get_vdev_features(&proxy->bus, >> >> proxy->host_features); >> -- >> 1.7.9.5 >>