diff options
| -rw-r--r-- | drivers/xen/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/xen/grant-dma-ops.c | 48 | ||||
| -rw-r--r-- | include/xen/xen-ops.h | 5 |
3 files changed, 47 insertions, 7 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 35d20d90390b..bfd5f4f706bc 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -347,6 +347,7 @@ config XEN_VIRTIO bool "Xen virtio support" depends on VIRTIO select XEN_GRANT_DMA_OPS + select XEN_GRANT_DMA_IOMMU if OF help Enable virtio support for running as Xen guest. Depending on the guest type this will require special support on the backend side diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c index aaff35cda517..fc0142484001 100644 --- a/drivers/xen/grant-dma-ops.c +++ b/drivers/xen/grant-dma-ops.c @@ -56,11 +56,6 @@ static struct xen_grant_dma_data *find_xen_grant_dma_data(struct device *dev) * Such a DMA address is formed by using the grant reference as a frame * number and setting the highest address bit (this bit is for the backend * to be able to distinguish it from e.g. a mmio address). - * - * Note that for now we hard wire dom0 to be the backend domain. In order - * to support any domain as backend we'd need to add a way to communicate - * the domid of this backend, e.g. via Xenstore, via the PCI-device's - * config space or DT/ACPI. */ static void *xen_grant_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, @@ -276,9 +271,26 @@ static const struct dma_map_ops xen_grant_dma_ops = { .dma_supported = xen_grant_dma_supported, }; +bool xen_is_grant_dma_device(struct device *dev) +{ + struct device_node *iommu_np; + bool has_iommu; + + /* XXX Handle only DT devices for now */ + if (!dev->of_node) + return false; + + iommu_np = of_parse_phandle(dev->of_node, "iommus", 0); + has_iommu = iommu_np && of_device_is_compatible(iommu_np, "xen,grant-dma"); + of_node_put(iommu_np); + + return has_iommu; +} + void xen_grant_setup_dma_ops(struct device *dev) { struct xen_grant_dma_data *data; + struct of_phandle_args iommu_spec; data = find_xen_grant_dma_data(dev); if (data) { @@ -286,12 +298,34 @@ void xen_grant_setup_dma_ops(struct device *dev) return; } + /* XXX ACPI device unsupported for now */ + if (!dev->of_node) + goto err; + + if (of_parse_phandle_with_args(dev->of_node, "iommus", "#iommu-cells", + 0, &iommu_spec)) { + dev_err(dev, "Cannot parse iommus property\n"); + goto err; + } + + if (!of_device_is_compatible(iommu_spec.np, "xen,grant-dma") || + iommu_spec.args_count != 1) { + dev_err(dev, "Incompatible IOMMU node\n"); + of_node_put(iommu_spec.np); + goto err; + } + + of_node_put(iommu_spec.np); + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) goto err; - /* XXX The dom0 is hardcoded as the backend domain for now */ - data->backend_domid = 0; + /* + * The endpoint ID here means the ID of the domain where the corresponding + * backend is running + */ + data->backend_domid = iommu_spec.args[0]; if (xa_err(xa_store(&xen_grant_dma_devices, (unsigned long)dev, data, GFP_KERNEL))) { diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index afd586d717a4..80546960f8b7 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -216,10 +216,15 @@ static inline void xen_preemptible_hcall_end(void) { } #ifdef CONFIG_XEN_GRANT_DMA_OPS void xen_grant_setup_dma_ops(struct device *dev); +bool xen_is_grant_dma_device(struct device *dev); #else static inline void xen_grant_setup_dma_ops(struct device *dev) { } +static inline bool xen_is_grant_dma_device(struct device *dev) +{ + return false; +} #endif /* CONFIG_XEN_GRANT_DMA_OPS */ #endif /* INCLUDE_XEN_OPS_H */ |