On Fri, 2013-08-30 at 20:15 +1000, Alexey Kardashevskiy wrote: > From: David Gibson <da...@gibson.dropbear.id.au> > > So far, VFIO has a notion of different logical DMA address spaces, but > only ever uses one (system memory). This patch extends this, creating > new VFIOAddressSpace objects as necessary, according to the AddressSpace > reported by the PCI subsystem for this device's DMAs. > > This isn't enough yet to support guest side IOMMUs with VFIO, but it does > mean we could now support VFIO devices on, for example, a guest side PCI > host bridge which maps system memory at somewhere other than 0 in PCI > space. > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > --- > hw/misc/vfio.c | 43 +++++++++++++++++++++++++++++++++++-------- > 1 file changed, 35 insertions(+), 8 deletions(-) > > diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c > index 93a316e..c16f41b 100644 > --- a/hw/misc/vfio.c > +++ b/hw/misc/vfio.c > @@ -133,9 +133,10 @@ enum { > typedef struct VFIOAddressSpace { > AddressSpace *as; > QLIST_HEAD(, VFIOContainer) containers; > + QLIST_ENTRY(VFIOAddressSpace) list; > } VFIOAddressSpace; > > -static VFIOAddressSpace vfio_address_space_memory; > +QLIST_HEAD(, VFIOAddressSpace) vfio_address_spaces; > > struct VFIOGroup; > > @@ -2611,10 +2612,34 @@ static int vfio_load_rom(VFIODevice *vdev) > return 0; > } > > -static void vfio_address_space_init(VFIOAddressSpace *space, AddressSpace > *as) > +static VFIOAddressSpace *vfio_get_address_space(AddressSpace *as) > { > + VFIOAddressSpace *space; > + > + QLIST_FOREACH(space, &vfio_address_spaces, list) { > + if (space->as == as) { > + return space; > + } > + } > + > + /* No suitable VFIOAddressSpace, create a new one */ > + space = g_malloc0(sizeof(*space)); > space->as = as; > QLIST_INIT(&space->containers); > + > + QLIST_INSERT_HEAD(&vfio_address_spaces, space, list); > + > + return space; > +} > + > +static void vfio_put_address_space(VFIOAddressSpace *space) > +{ > + if (!QLIST_EMPTY(&space->containers)) { > + return; > + } > + > + QLIST_REMOVE(space, list); > + g_free(space); > } > > static int vfio_connect_container(VFIOGroup *group, VFIOAddressSpace *space) > @@ -2699,6 +2724,8 @@ static void vfio_disconnect_container(VFIOGroup *group) > group->container = NULL; > > if (QLIST_EMPTY(&container->group_list)) { > + VFIOAddressSpace *space = container->space; > + > if (container->iommu_data.release) { > container->iommu_data.release(container); > } > @@ -2706,6 +2733,8 @@ static void vfio_disconnect_container(VFIOGroup *group) > DPRINTF("vfio_disconnect_container: close container->fd\n"); > close(container->fd); > g_free(container); > + > + vfio_put_address_space(space); > } > } > > @@ -3076,6 +3105,7 @@ static int vfio_initfn(PCIDevice *pdev) > { > VFIODevice *pvdev, *vdev = DO_UPCAST(VFIODevice, pdev, pdev); > VFIOGroup *group; > + VFIOAddressSpace *space; > char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name; > ssize_t len; > struct stat st; > @@ -3111,14 +3141,12 @@ static int vfio_initfn(PCIDevice *pdev) > DPRINTF("%s(%04x:%02x:%02x.%x) group %d\n", __func__, vdev->host.domain, > vdev->host.bus, vdev->host.slot, vdev->host.function, groupid); > > - if (pci_device_iommu_address_space(pdev) != &address_space_memory) { > - error_report("vfio: DMA address space must be system memory"); > - return -EINVAL; > - } > + space = vfio_get_address_space(pci_device_iommu_address_space(pdev)); > > - group = vfio_get_group(groupid, &vfio_address_space_memory); > + group = vfio_get_group(groupid, space); > if (!group) { > error_report("vfio: failed to get group %d", groupid); > + vfio_put_address_space(space); > return -ENOENT; > } >
Kind of a code flow issue here, on teardown we have: vfio_put_group vfio_disconnect_container vfio_put_address_space On setup we do: vfio_get_address_space vfio_get_group vfio_connect_container We could easily move vfio_get_address_space into vfio_get_group to make things a little more balanced. It doesn't seem like too much additional to pass the address space through vfio_get_group into vfio_connect_container so that we could have a completely symmetric flow though. > @@ -3339,7 +3367,6 @@ static const TypeInfo vfio_pci_dev_info = { > > static void register_vfio_pci_dev_type(void) > { > - vfio_address_space_init(&vfio_address_space_memory, > &address_space_memory); > type_register_static(&vfio_pci_dev_info); > } >