On Tue, Feb 20, 2024 at 3:41 PM Michael S. Tsirkin <m...@redhat.com> wrote:
>
> On Tue, Feb 20, 2024 at 12:39:35PM +0530, Srujana Challa wrote:
> > Currently, virtio_pci_queue_mem_mult function always returns 4K
> > when VIRTIO_PCI_FLAG_PAGE_PER_VQ is set. But this won't
> > work for vhost vdpa when host has page size other than 4K.
> > This patch introduces a new property(page-per-vdpa-vq) for vdpa
> > use case to fix the same.
> >
> > Signed-off-by: Srujana Challa <scha...@marvell.com>
> > ---
> > v1->v2:
> > - Introduced a new property to get virtqueue mem multiplier for
> > vdpa use case.
>
>
> OK, I would maybe call it host-page-per-vq?
>
> Jason?
>
I agree.
Thanks
> > hw/virtio/virtio-pci.c | 10 ++++++++--
> > include/hw/virtio/virtio-pci.h | 5 +++++
> > 2 files changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> > index 1a7039fb0c..28dd6ab8b5 100644
> > --- a/hw/virtio/virtio-pci.c
> > +++ b/hw/virtio/virtio-pci.c
> > @@ -320,8 +320,12 @@ static bool virtio_pci_ioeventfd_enabled(DeviceState
> > *d)
> >
> > static inline int virtio_pci_queue_mem_mult(struct VirtIOPCIProxy *proxy)
> > {
> > - return (proxy->flags & VIRTIO_PCI_FLAG_PAGE_PER_VQ) ?
> > - QEMU_VIRTIO_PCI_QUEUE_MEM_MULT : 4;
> > + if (proxy->flags & VIRTIO_PCI_FLAG_PAGE_PER_VQ)
> > + return QEMU_VIRTIO_PCI_QUEUE_MEM_MULT;
> > + else if (proxy->flags & VIRTIO_PCI_FLAG_PAGE_PER_VDPA_VQ)
> > + return qemu_real_host_page_size();
> > + else
> > + return 4;
> > }
> >
> > static int virtio_pci_ioeventfd_assign(DeviceState *d, EventNotifier
> > *notifier,
> > @@ -2301,6 +2305,8 @@ static Property virtio_pci_properties[] = {
> > VIRTIO_PCI_FLAG_INIT_FLR_BIT, true),
> > DEFINE_PROP_BIT("aer", VirtIOPCIProxy, flags,
> > VIRTIO_PCI_FLAG_AER_BIT, false),
> > + DEFINE_PROP_BIT("page-per-vdpa-vq", VirtIOPCIProxy, flags,
> > + VIRTIO_PCI_FLAG_PAGE_PER_VDPA_VQ_BIT, false),
> > DEFINE_PROP_END_OF_LIST(),
> > };
> >
> > diff --git a/include/hw/virtio/virtio-pci.h b/include/hw/virtio/virtio-pci.h
> > index 59d88018c1..10a30c26a2 100644
> > --- a/include/hw/virtio/virtio-pci.h
> > +++ b/include/hw/virtio/virtio-pci.h
> > @@ -43,6 +43,7 @@ enum {
> > VIRTIO_PCI_FLAG_INIT_FLR_BIT,
> > VIRTIO_PCI_FLAG_AER_BIT,
> > VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT,
> > + VIRTIO_PCI_FLAG_PAGE_PER_VDPA_VQ_BIT,
> > };
> >
> > /* Need to activate work-arounds for buggy guests at vmstate load. */
> > @@ -89,6 +90,10 @@ enum {
> > #define VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED \
> > (1 << VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT)
> >
> > +/* page per vdpa vq flag to be used for vhost vdpa backends */
> > +#define VIRTIO_PCI_FLAG_PAGE_PER_VDPA_VQ \
> > + (1 << VIRTIO_PCI_FLAG_PAGE_PER_VDPA_VQ_BIT)
> > +
> > typedef struct {
> > MSIMessage msg;
> > int virq;
> > --
> > 2.25.1
>
