[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-ppc] [PATCH v4 02/12] vfio: Create VFIOAddressSpace objects as
From: |
Alex Williamson |
Subject: |
Re: [Qemu-ppc] [PATCH v4 02/12] vfio: Create VFIOAddressSpace objects as needed |
Date: |
Thu, 05 Sep 2013 12:24:53 -0600 |
On Fri, 2013-08-30 at 20:15 +1000, Alexey Kardashevskiy wrote:
> From: David Gibson <address@hidden>
>
> 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 <address@hidden>
> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> ---
> 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);
> }
>
- Re: [Qemu-ppc] [PATCH v4 02/12] vfio: Create VFIOAddressSpace objects as needed,
Alex Williamson <=