On Wed, Jun 13, 2012 at 12:44:01PM +0200, Jan Kiszka wrote:
> On 2012-06-12 22:03, Alex Williamson wrote:
> > msix_init has very little configurability as to how it lays out MSIX
> > for a device. It claims to resize BARs, but doesn't actually do this
> > anymore. This patch allows MSIX to be fully specified, which is
> > necessary both for emulated devices trying to match the physical
> > layout of a hardware device as well as for any kind of device
> > assignment.
> >
> > New functions msix_init_bar & msix_uninit_bar provide wrappers around
> > the more detailed functions for drivers that just want a simple MSIX
> > setup.
> >
> > Signed-off-by: Alex Williamson <alex.william...@redhat.com>
> > ---
> >
> > hw/ivshmem.c | 9 +-
> > hw/msix.c | 299
> > +++++++++++++++++++++++++++++++------------------------
> > hw/msix.h | 11 +-
> > hw/pci.h | 12 ++
> > hw/virtio-pci.c | 15 +--
> > 5 files changed, 192 insertions(+), 154 deletions(-)
> >
> > diff --git a/hw/ivshmem.c b/hw/ivshmem.c
> > index 05559b6..71c84a6 100644
> > --- a/hw/ivshmem.c
> > +++ b/hw/ivshmem.c
> > @@ -563,16 +563,13 @@ static uint64_t ivshmem_get_size(IVShmemState * s) {
> >
> > static void ivshmem_setup_msi(IVShmemState * s)
> > {
> > - memory_region_init(&s->msix_bar, "ivshmem-msix", 4096);
> > - if (!msix_init(&s->dev, s->vectors, &s->msix_bar, 1, 0)) {
> > - pci_register_bar(&s->dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY,
> > - &s->msix_bar);
> > - IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
> > - } else {
> > + if (msix_init_bar(&s->dev, s->vectors, &s->msix_bar, 1,
> > "ivshmem-msix")) {
>
> I don't think the callers of msix_init_bar should have to provide the
> memory region for that bar. That can be embedded into PCIDevice, just
> like you did for the table and PBA. That was my idea with msix_init_simple.
>
> Back then, I only included a generic memory region name. That can be
> improved, but without bothering the caller. Just derive it from
> PCIDevice::name.
>
> Jan
I think callers must initialize the BAR regions.
This is because BAR can include other stuff besides MSI-X.
MSI-X adds its own subregion.
It is a bit ugly that we provide both BAR region and BAR number.
We could register BAR and afterwards add subregions,
if we do, passing either BAR # or BAR region is enough.
To do this we need to add pci_unregister_bar
so we can handle msix_init failures gracefully.
Anyone sees any problems with this?
> --
> Siemens AG, Corporate Technology, CT T DE IT 1
> Corporate Competence Center Embedded Linux
