Re: [PATCH] hw/virtio: enable ioeventfd configuring for mmio

[Pavel Dovgalyuk]

ping

On 06.04.2021 13:02, Michael S. Tsirkin wrote:
> i tagged it for 6.1
> pls remind me after release so it's not lost
>
>
> On Mon, Apr 05, 2021 at 08:50:31AM +0300, Pavel Dovgalyuk wrote:
> > ping
> >
> > On 29.03.2021 10:43, Pavel Dovgalyuk wrote:
> > > This patch adds ioeventfd flag for virtio-mmio configuration.
> > > It allows switching ioeventfd on and off.
> > >
> > > Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
> > > ---
> > >    hw/virtio/virtio-mmio.c         |   11 ++++++++++-
> > >    include/hw/virtio/virtio-mmio.h |    5 +++++
> > >    2 files changed, 15 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
> > > index 342c918ea7..5952471b38 100644
> > > --- a/hw/virtio/virtio-mmio.c
> > > +++ b/hw/virtio/virtio-mmio.c
> > > @@ -36,7 +36,9 @@
> > >    static bool virtio_mmio_ioeventfd_enabled(DeviceState *d)
> > >    {
> > > -    return kvm_eventfds_enabled();
> > > +    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
> > > +
> > > +    return (proxy->flags & VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD) != 0;
> > >    }
> > >    static int virtio_mmio_ioeventfd_assign(DeviceState *d,
> > > @@ -720,6 +722,8 @@ static Property virtio_mmio_properties[] = {
> > >        DEFINE_PROP_BOOL("format_transport_address", VirtIOMMIOProxy,
> > >                         format_transport_address, true),
> > >        DEFINE_PROP_BOOL("force-legacy", VirtIOMMIOProxy, legacy, true),
> > > +    DEFINE_PROP_BIT("ioeventfd", VirtIOMMIOProxy, flags,
> > > +                    VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD_BIT, true),
> > >        DEFINE_PROP_END_OF_LIST(),
> > >    };
> > > @@ -731,6 +735,11 @@ static void virtio_mmio_realizefn(DeviceState *d, Error 
> > > **errp)
> > >        qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), 
> > > TYPE_VIRTIO_MMIO_BUS,
> > >                            d, NULL);
> > >        sysbus_init_irq(sbd, &proxy->irq);
> > > +
> > > +    if (!kvm_eventfds_enabled()) {
> > > +        proxy->flags &= ~VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD;
> > > +    }
> > > +
> > >        if (proxy->legacy) {
> > >            memory_region_init_io(&proxy->iomem, OBJECT(d),
> > >                                  &virtio_legacy_mem_ops, proxy,
> > > diff --git a/include/hw/virtio/virtio-mmio.h b/include/hw/virtio/virtio-mmio.h
> > > index d4c4c386ab..090f7730e7 100644
> > > --- a/include/hw/virtio/virtio-mmio.h
> > > +++ b/include/hw/virtio/virtio-mmio.h
> > > @@ -49,12 +49,17 @@ typedef struct VirtIOMMIOQueue {
> > >        uint32_t used[2];
> > >    } VirtIOMMIOQueue;
> > > +#define VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD_BIT 1
> > > +#define VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD \
> > > +        (1 << VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD_BIT)
> > > +
> > >    struct VirtIOMMIOProxy {
> > >        /* Generic */
> > >        SysBusDevice parent_obj;
> > >        MemoryRegion iomem;
> > >        qemu_irq irq;
> > >        bool legacy;
> > > +    uint32_t flags;
> > >        /* Guest accessible state needing migration and reset */
> > >        uint32_t host_features_sel;
> > >        uint32_t guest_features_sel;