On Fri, Aug 15, 2014 at 08:12:29PM +1000, Alexey Kardashevskiy wrote: > This adds support for Dynamic DMA Windows (DDW) option defined by > the SPAPR specification which allows to have additional DMA window(s) > which can support page sizes other than 4K. > > The existing implementation of DDW in the guest tries to create one huge > DMA window with 64K or 16MB pages and map the entire guest RAM to. If it > succeeds, the guest switches to dma_direct_ops and never calls > TCE hypercalls (H_PUT_TCE,...) again. This enables VFIO devices to use > the entire RAM and not waste time on map/unmap. > > This adds 4 RTAS handlers: > * ibm,query-pe-dma-window > * ibm,create-pe-dma-window > * ibm,remove-pe-dma-window > * ibm,reset-pe-dma-window > These are registered from type_init() callback. > > These RTAS handlers are implemented in a separate file to avoid polluting > spapr_iommu.c with PHB. > > Since no PHB class implements new callback in this patch, no functional > change is expected.
[snip]
> +static void rtas_ibm_create_pe_dma_window(PowerPCCPU *cpu,
> + sPAPREnvironment *spapr,
> + uint32_t token, uint32_t nargs,
> + target_ulong args,
> + uint32_t nret, target_ulong rets)
> +{
> + sPAPRPHBState *sphb;
> + sPAPRPHBClass *spc;
> + sPAPRTCETable *tcet = NULL;
> + uint32_t addr, page_shift, window_shift, liobn;
> + uint64_t buid;
> + long ret;
> +
> + if ((nargs != 5) || (nret != 4)) {
> + goto param_error_exit;
> + }
> +
> + buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 2);
> + addr = rtas_ld(args, 0);
> + sphb = spapr_pci_find_phb(spapr, buid);
> + if (!sphb) {
> + goto param_error_exit;
> + }
> +
> + spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
> + if (!spc->ddw_create) {
> + goto hw_error_exit;
> + }
> +
> + page_shift = rtas_ld(args, 3);
> + window_shift = rtas_ld(args, 4);
> + /* Default 32bit window#0 is always there so +1 */
> + liobn = SPAPR_PCI_LIOBN(sphb->index, sphb->ddw_num + 1);
> +
> + ret = spc->ddw_create(sphb, page_shift, window_shift, liobn, &tcet);
> + trace_spapr_iommu_ddw_create(buid, addr, 1ULL << page_shift,
> + 1ULL << window_shift,
> + tcet ? tcet->bus_offset : 0xbaadf00d,
> + liobn, ret);
> + if (ret || !tcet) {
> + goto hw_error_exit;
> + }
> +
> + sphb->ddw_num++;
You increment ddw_num here...
[snip]
> +static void rtas_ibm_remove_pe_dma_window(PowerPCCPU *cpu,
> + sPAPREnvironment *spapr,
> + uint32_t token, uint32_t nargs,
> + target_ulong args,
> + uint32_t nret, target_ulong rets)
> +{
> + sPAPRPHBState *sphb;
> + sPAPRPHBClass *spc;
> + sPAPRTCETable *tcet;
> + uint32_t liobn;
> + long ret;
> +
> + if ((nargs != 1) || (nret != 1)) {
> + goto param_error_exit;
> + }
> +
> + liobn = rtas_ld(args, 0);
> + tcet = spapr_tce_find_by_liobn(liobn);
> + if (!tcet) {
> + goto param_error_exit;
> + }
> +
> + sphb = SPAPR_PCI_HOST_BRIDGE(OBJECT(tcet)->parent);
> + if (!sphb) {
> + goto param_error_exit;
> + }
> +
> + spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
> + if (!spc->ddw_remove) {
> + goto hw_error_exit;
> + }
> +
> + ret = spc->ddw_remove(sphb, tcet);
> + trace_spapr_iommu_ddw_remove(liobn, ret);
> + if (ret) {
> + goto hw_error_exit;
> + }
> +
> + rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> + return;
.. but don't decrement it here. Is that a bug?
[snip]
> +static void rtas_ibm_reset_pe_dma_window(PowerPCCPU *cpu,
> + sPAPREnvironment *spapr,
> + uint32_t token, uint32_t nargs,
> + target_ulong args,
> + uint32_t nret, target_ulong rets)
> +{
> + sPAPRPHBState *sphb;
> + sPAPRPHBClass *spc;
> + uint64_t buid;
> + uint32_t addr;
> + long ret;
> +
> + if ((nargs != 3) || (nret != 1)) {
> + goto param_error_exit;
> + }
> +
> + buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 2);
> + addr = rtas_ld(args, 0);
> + sphb = spapr_pci_find_phb(spapr, buid);
> + if (!sphb) {
> + goto param_error_exit;
> + }
> +
> + spc = SPAPR_PCI_HOST_BRIDGE_GET_CLASS(sphb);
> + if (!spc->ddw_reset) {
> + goto hw_error_exit;
> + }
> +
> + ret = spc->ddw_reset(sphb);
> + trace_spapr_iommu_ddw_reset(buid, addr, ret);
> + if (ret) {
> + goto hw_error_exit;
> + }
Likewise ddw_num doesn't seem to be reset here.
--
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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