On Tue, Mar 01, 2016 at 08:10:29PM +1100, Alexey Kardashevskiy wrote: > Currently TCE tables are created once at start and their sizes never > change. We are going to change that by introducing a Dynamic DMA windows > support where DMA configuration may change during the guest execution. > > This changes spapr_tce_new_table() to create an empty zero-size IOMMU > memory region (IOMMU MR). Only LIOBN is assigned by the time of creation. > It still will be called once at the owner object (VIO or PHB) creation. > > This introduces an "enabled" state for TCE table objects with two > helper functions - spapr_tce_table_enable()/spapr_tce_table_disable(). > - spapr_tce_table_enable() receives TCE table parameters, allocates > a guest view of the TCE table (in the user space or KVM) and > sets the correct size on the IOMMU MR. > - spapr_tce_table_disable() disposes the table and resets the IOMMU MR > size. > > This changes the PHB reset handler to do the default DMA initialization > instead of spapr_phb_realize(). This does not make differenct now but > later with more than just one DMA window, we will have to remove them all > and create the default one on a system reset. > > No visible change in behaviour is expected except the actual table > will be reallocated every reset. We might optimize this later. > > The other way to implement this would be dynamically create/remove > the TCE table QOM objects but this would make migration impossible > as the migration code expects all QOM objects to exist at the receiver > so we have to have TCE table objects created when migration begins. > > spapr_tce_table_do_enable() is separated from from spapr_tce_table_enable() > as later it will be called at the sPAPRTCETable post-migration stage when > it already has all the properties set after the migration. > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
Although there's one nit that could be improved:
> ---
> hw/ppc/spapr_iommu.c | 80
> +++++++++++++++++++++++++++++++++++---------------
> hw/ppc/spapr_pci.c | 21 +++++++++----
> hw/ppc/spapr_vio.c | 9 +++---
> include/hw/ppc/spapr.h | 10 +++----
> 4 files changed, 80 insertions(+), 40 deletions(-)
>
> diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
> index 8132f64..e66e128 100644
> --- a/hw/ppc/spapr_iommu.c
> +++ b/hw/ppc/spapr_iommu.c
> @@ -174,15 +174,8 @@ static int spapr_tce_table_realize(DeviceState *dev)
> sPAPRTCETable *tcet = SPAPR_TCE_TABLE(dev);
>
> tcet->fd = -1;
> - tcet->table = spapr_tce_alloc_table(tcet->liobn,
> - tcet->page_shift,
> - tcet->nb_table,
> - &tcet->fd,
> - tcet->need_vfio);
> -
> memory_region_init_iommu(&tcet->iommu, OBJECT(dev), &spapr_iommu_ops,
> - "iommu-spapr",
> - (uint64_t)tcet->nb_table << tcet->page_shift);
> + "iommu-spapr", 0);
>
> QLIST_INSERT_HEAD(&spapr_tce_tables, tcet, list);
>
> @@ -224,14 +217,10 @@ void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool
> need_vfio)
> tcet->table = newtable;
> }
>
> -sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
> - uint64_t bus_offset,
> - uint32_t page_shift,
> - uint32_t nb_table,
> - bool need_vfio)
> +sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn)
> {
> sPAPRTCETable *tcet;
> - char tmp[64];
> + char tmp[32];
>
> if (spapr_tce_find_by_liobn(liobn)) {
> fprintf(stderr, "Attempted to create TCE table with duplicate"
> @@ -239,16 +228,8 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner,
> uint32_t liobn,
> return NULL;
> }
>
> - if (!nb_table) {
> - return NULL;
> - }
> -
> tcet = SPAPR_TCE_TABLE(object_new(TYPE_SPAPR_TCE_TABLE));
> tcet->liobn = liobn;
> - tcet->bus_offset = bus_offset;
> - tcet->page_shift = page_shift;
> - tcet->nb_table = nb_table;
> - tcet->need_vfio = need_vfio;
>
> snprintf(tmp, sizeof(tmp), "tce-table-%x", liobn);
> object_property_add_child(OBJECT(owner), tmp, OBJECT(tcet), NULL);
> @@ -258,14 +239,65 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner,
> uint32_t liobn,
> return tcet;
> }
>
> +static void spapr_tce_table_do_enable(sPAPRTCETable *tcet)
> +{
> + if (!tcet->nb_table) {
> + return;
> + }
> +
> + tcet->table = spapr_tce_alloc_table(tcet->liobn,
> + tcet->page_shift,
> + tcet->nb_table,
> + &tcet->fd,
> + tcet->need_vfio);
> +
> + memory_region_set_size(&tcet->iommu,
> + (uint64_t)tcet->nb_table << tcet->page_shift);
> +
> + tcet->enabled = true;
> +}
> +
> +void spapr_tce_table_enable(sPAPRTCETable *tcet,
> + uint32_t page_shift, uint64_t bus_offset,
> + uint32_t nb_table, bool need_vfio)
> +{
> + if (tcet->enabled) {
> + return;
If the given parameters are different from the current ones, treating
this as a no-op is rather misleading. I gather that to resize the
window you're expected to disable, then re-enable. In which case I
think it would be safer to actually throw some kind of error on a
double enable.
> + }
> +
> + tcet->bus_offset = bus_offset;
> + tcet->page_shift = page_shift;
> + tcet->nb_table = nb_table;
> + tcet->need_vfio = need_vfio;
> +
> + spapr_tce_table_do_enable(tcet);
> +}
> +
> +static void spapr_tce_table_disable(sPAPRTCETable *tcet)
> +{
> + if (!tcet->enabled) {
> + return;
> + }
> +
> + memory_region_set_size(&tcet->iommu, 0);
> +
> + spapr_tce_free_table(tcet->table, tcet->fd, tcet->nb_table);
> + tcet->fd = -1;
> + tcet->table = NULL;
> + tcet->enabled = false;
> + tcet->bus_offset = 0;
> + tcet->page_shift = 0;
> + tcet->nb_table = 0;
> + tcet->need_vfio = false;
> +}
> +
> static void spapr_tce_table_unrealize(DeviceState *dev, Error **errp)
> {
> sPAPRTCETable *tcet = SPAPR_TCE_TABLE(dev);
>
> QLIST_REMOVE(tcet, list);
>
> - spapr_tce_free_table(tcet->table, tcet->fd, tcet->nb_table);
> - tcet->fd = -1;
> + spapr_tce_table_disable(tcet);
> }
>
> MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet)
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 248f20a..c34a906 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -815,12 +815,13 @@ static int spapr_phb_dma_window_enable(sPAPRPHBState
> *sphb,
> return -1;
> }
>
> - tcet = spapr_tce_new_table(DEVICE(sphb), liobn, window_addr,
> - page_shift, nb_table, false);
> + tcet = spapr_tce_find_by_liobn(liobn);
> if (!tcet) {
> return -1;
> }
>
> + spapr_tce_table_enable(tcet, page_shift, window_addr, nb_table, false);
> +
> memory_region_add_subregion(&sphb->iommu_root, tcet->bus_offset,
> spapr_tce_get_iommu(tcet));
> return 0;
> @@ -1251,6 +1252,7 @@ static void spapr_phb_realize(DeviceState *dev, Error
> **errp)
> int i;
> PCIBus *bus;
> uint64_t msi_window_size = 4096;
> + sPAPRTCETable *tcet;
>
> if (sphb->index != (uint32_t)-1) {
> hwaddr windows_base;
> @@ -1402,11 +1404,18 @@ static void spapr_phb_realize(DeviceState *dev, Error
> **errp)
> }
> }
>
> + /* DMA setup */
> + tcet = spapr_tce_new_table(DEVICE(sphb), sphb->dma_liobn);
> + if (!tcet) {
> + error_report("No default TCE table for %s", sphb->dtbusname);
> + return;
> + }
> +
> /* Register default 32bit DMA window */
> - if (spapr_phb_dma_window_enable(sphb, sphb->dma_liobn,
> SPAPR_TCE_PAGE_SHIFT,
> - sphb->dma_win_addr, sphb->dma_win_size))
> {
> - error_setg(errp, "Unable to create TCE table for %s",
> sphb->dtbusname);
> - }
> + spapr_phb_dma_window_enable(sphb, sphb->dma_liobn,
> + SPAPR_TCE_PAGE_SHIFT,
> + sphb->dma_win_addr,
> + sphb->dma_win_size);
>
> sphb->msi = g_hash_table_new_full(g_int_hash, g_int_equal, g_free,
> g_free);
> }
> diff --git a/hw/ppc/spapr_vio.c b/hw/ppc/spapr_vio.c
> index 0f61a55..a745884 100644
> --- a/hw/ppc/spapr_vio.c
> +++ b/hw/ppc/spapr_vio.c
> @@ -481,11 +481,10 @@ static void spapr_vio_busdev_realize(DeviceState *qdev,
> Error **errp)
> memory_region_add_subregion_overlap(&dev->mrroot, 0, &dev->mrbypass,
> 1);
> address_space_init(&dev->as, &dev->mrroot, qdev->id);
>
> - dev->tcet = spapr_tce_new_table(qdev, liobn,
> - 0,
> - SPAPR_TCE_PAGE_SHIFT,
> - pc->rtce_window_size >>
> - SPAPR_TCE_PAGE_SHIFT, false);
> + dev->tcet = spapr_tce_new_table(qdev, liobn);
> + spapr_tce_table_enable(dev->tcet, SPAPR_TCE_PAGE_SHIFT, 0,
> + pc->rtce_window_size >> SPAPR_TCE_PAGE_SHIFT,
> + false);
> dev->tcet->vdev = dev;
> memory_region_add_subregion_overlap(&dev->mrroot, 0,
> spapr_tce_get_iommu(dev->tcet),
> 2);
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 098d85d..3e6bb84 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -539,6 +539,7 @@ typedef struct sPAPRTCETable sPAPRTCETable;
>
> struct sPAPRTCETable {
> DeviceState parent;
> + bool enabled;
> uint32_t liobn;
> uint32_t nb_table;
> uint64_t bus_offset;
> @@ -566,11 +567,10 @@ void spapr_events_fdt_skel(void *fdt, uint32_t
> epow_irq);
> int spapr_h_cas_compose_response(sPAPRMachineState *sm,
> target_ulong addr, target_ulong size,
> bool cpu_update, bool memory_update);
> -sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
> - uint64_t bus_offset,
> - uint32_t page_shift,
> - uint32_t nb_table,
> - bool need_vfio);
> +sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn);
> +void spapr_tce_table_enable(sPAPRTCETable *tcet,
> + uint32_t page_shift, uint64_t bus_offset,
> + uint32_t nb_table, bool vfio_accel);
> void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool need_vfio);
>
> MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet);
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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