Add a driver for the ACPI VIOT table, which enables virtio-iommu on non-devicetree platforms, including x86. This series depends on the ACPICA changes of patch 1, which will be included in next release [1] and pulled into Linux. The Virtual I/O Translation table (VIOT) describes the topology of para-virtual I/O translation devices and the endpoints they manage. It was recently approved for inclusion into the ACPI standard [2]. A provisional version of the specification can be found at [3]. After discussing non-devicetree support for virtio-iommu at length [4][5][6] we concluded that it should use this new ACPI table. And for platforms that don't implement either devicetree or ACPI, a structure that uses roughly the same format [6] can be built into the device. [1] https://github.com/acpica/acpica/pull/666 [2] https://lore.kernel.org/linux-iommu/20210218233943.GH702808 at redhat.com/ [3] https://jpbrucker.net/virtio-iommu/viot/viot-v9.pdf [4] https://lore.kernel.org/linux-iommu/20191122105000.800410-1-jean-philippe at linaro.org/ [5] https://lore.kernel.org/linux-iommu/20200228172537.377327-1-jean-philippe at linaro.org/ [6] https://lore.kernel.org/linux-iommu/20200821131540.2801801-1-jean-philippe at linaro.org/ Jean-Philippe Brucker (3): ACPICA: iASL: Add definitions for the VIOT table ACPI: Add driver for the VIOT table iommu/virtio: Enable x86 support drivers/acpi/Kconfig | 3 + drivers/iommu/Kconfig | 4 +- drivers/acpi/Makefile | 2 + include/acpi/actbl3.h | 67 ++++++ include/linux/acpi_viot.h | 26 +++ drivers/acpi/bus.c | 2 + drivers/acpi/scan.c | 6 + drivers/acpi/viot.c | 406 +++++++++++++++++++++++++++++++++++ drivers/iommu/virtio-iommu.c | 3 + MAINTAINERS | 8 + 10 files changed, 526 insertions(+), 1 deletion(-) create mode 100644 include/linux/acpi_viot.h create mode 100644 drivers/acpi/viot.c -- 2.30.2
Jean-Philippe Brucker
2021-Mar-16 19:16 UTC
[PATCH 1/3] ACPICA: iASL: Add definitions for the VIOT table
Just here for reference, don't merge!
The actual commits will be pulled from the next ACPICA release.
I squashed the three relevant commits:
ACPICA commit fc4e33319c1ee08f20f5c44853dd8426643f6dfd
ACPICA commit 2197e354fb5dcafaddd2016ffeb0620e5bc3d5e2
ACPICA commit 856a96fdf4b51b2b8da17529df0255e6f51f1b5b
Link: https://github.com/acpica/acpica/commit/fc4e3331
Link: https://github.com/acpica/acpica/commit/2197e354
Link: https://github.com/acpica/acpica/commit/856a96fd
Signed-off-by: Bob Moore <robert.moore at intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
---
include/acpi/actbl3.h | 67 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 67 insertions(+)
diff --git a/include/acpi/actbl3.h b/include/acpi/actbl3.h
index df5f4b27f3aa..09d15898e9a8 100644
--- a/include/acpi/actbl3.h
+++ b/include/acpi/actbl3.h
@@ -33,6 +33,7 @@
#define ACPI_SIG_TCPA "TCPA" /* Trusted Computing Platform
Alliance table */
#define ACPI_SIG_TPM2 "TPM2" /* Trusted Platform Module 2.0
H/W interface table */
#define ACPI_SIG_UEFI "UEFI" /* Uefi Boot Optimization
Table */
+#define ACPI_SIG_VIOT "VIOT" /* Virtual I/O Translation
Table */
#define ACPI_SIG_WAET "WAET" /* Windows ACPI Emulated
devices Table */
#define ACPI_SIG_WDAT "WDAT" /* Watchdog Action Table */
#define ACPI_SIG_WDDT "WDDT" /* Watchdog Timer Description
Table */
@@ -483,6 +484,72 @@ struct acpi_table_uefi {
u16 data_offset; /* Offset of remaining data in table */
};
+/*******************************************************************************
+ *
+ * VIOT - Virtual I/O Translation Table
+ * Version 1
+ *
+
******************************************************************************/
+
+struct acpi_table_viot {
+ struct acpi_table_header header; /* Common ACPI table header */
+ u16 node_count;
+ u16 node_offset;
+ u8 reserved[8];
+};
+
+/* VIOT subtable header */
+
+struct acpi_viot_header {
+ u8 type;
+ u8 reserved;
+ u16 length;
+};
+
+/* Values for Type field above */
+
+enum acpi_viot_node_type {
+ ACPI_VIOT_NODE_PCI_RANGE = 0x01,
+ ACPI_VIOT_NODE_MMIO = 0x02,
+ ACPI_VIOT_NODE_VIRTIO_IOMMU_PCI = 0x03,
+ ACPI_VIOT_NODE_VIRTIO_IOMMU_MMIO = 0x04,
+ ACPI_VIOT_RESERVED = 0x05
+};
+
+/* VIOT subtables */
+
+struct acpi_viot_pci_range {
+ struct acpi_viot_header header;
+ u32 endpoint_start;
+ u16 segment_start;
+ u16 segment_end;
+ u16 bdf_start;
+ u16 bdf_end;
+ u16 output_node;
+ u8 reserved[6];
+};
+
+struct acpi_viot_mmio {
+ struct acpi_viot_header header;
+ u32 endpoint;
+ u64 base_address;
+ u16 output_node;
+ u8 reserved[6];
+};
+
+struct acpi_viot_virtio_iommu_pci {
+ struct acpi_viot_header header;
+ u16 segment;
+ u16 bdf;
+ u8 reserved[8];
+};
+
+struct acpi_viot_virtio_iommu_mmio {
+ struct acpi_viot_header header;
+ u8 reserved[4];
+ u64 base_address;
+};
+
/*******************************************************************************
*
* WAET - Windows ACPI Emulated devices Table
--
2.30.2
Jean-Philippe Brucker
2021-Mar-16 19:16 UTC
[PATCH 2/3] ACPI: Add driver for the VIOT table
The ACPI Virtual I/O Translation Table describes topology of
para-virtual platforms. For now it describes the relation between
virtio-iommu and the endpoints it manages. Supporting that requires
three steps:
(1) acpi_viot_init(): parse the VIOT table, build a list of endpoints
and vIOMMUs.
(2) acpi_viot_set_iommu_ops(): when the vIOMMU driver is loaded and the
device probed, register it to the VIOT driver. This step is required
because unlike similar drivers, VIOT doesn't create the vIOMMU
device.
(3) acpi_viot_dma_setup(): when the endpoint is initialized, find the
vIOMMU and register the endpoint's DMA ops.
If step (3) happens before step (2), it is deferred until the IOMMU is
initialized, then retried.
Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
---
drivers/acpi/Kconfig | 3 +
drivers/iommu/Kconfig | 1 +
drivers/acpi/Makefile | 2 +
include/linux/acpi_viot.h | 26 +++
drivers/acpi/bus.c | 2 +
drivers/acpi/scan.c | 6 +
drivers/acpi/viot.c | 406 +++++++++++++++++++++++++++++++++++
drivers/iommu/virtio-iommu.c | 3 +
MAINTAINERS | 8 +
9 files changed, 457 insertions(+)
create mode 100644 include/linux/acpi_viot.h
create mode 100644 drivers/acpi/viot.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index eedec61e3476..3758c6940ed7 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -526,6 +526,9 @@ endif
source "drivers/acpi/pmic/Kconfig"
+config ACPI_VIOT
+ bool
+
endif # ACPI
config X86_PM_TIMER
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 192ef8f61310..2819b5c8ec30 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -403,6 +403,7 @@ config VIRTIO_IOMMU
depends on ARM64
select IOMMU_API
select INTERVAL_TREE
+ select ACPI_VIOT if ACPI
help
Para-virtualised IOMMU driver with virtio.
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 700b41adf2db..a6e644c48987 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -118,3 +118,5 @@ video-objs += acpi_video.o video_detect.o
obj-y += dptf/
obj-$(CONFIG_ARM64) += arm64/
+
+obj-$(CONFIG_ACPI_VIOT) += viot.o
diff --git a/include/linux/acpi_viot.h b/include/linux/acpi_viot.h
new file mode 100644
index 000000000000..1f5837595488
--- /dev/null
+++ b/include/linux/acpi_viot.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ACPI_VIOT_H__
+#define __ACPI_VIOT_H__
+
+#include <linux/acpi.h>
+
+#ifdef CONFIG_ACPI_VIOT
+void __init acpi_viot_init(void);
+int acpi_viot_dma_setup(struct device *dev, enum dev_dma_attr attr);
+int acpi_viot_set_iommu_ops(struct device *dev, struct iommu_ops *ops);
+#else
+static inline void acpi_viot_init(void) {}
+static inline int acpi_viot_dma_setup(struct device *dev,
+ enum dev_dma_attr attr)
+{
+ return 0;
+}
+static inline int acpi_viot_set_iommu_ops(struct device *dev,
+ struct iommu_ops *ops)
+{
+ return -ENODEV;
+}
+#endif
+
+#endif /* __ACPI_VIOT_H__ */
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index be7da23fad76..f9a965c6617e 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -27,6 +27,7 @@
#include <linux/dmi.h>
#endif
#include <linux/acpi_iort.h>
+#include <linux/acpi_viot.h>
#include <linux/pci.h>
#include <acpi/apei.h>
#include <linux/suspend.h>
@@ -1338,6 +1339,7 @@ static int __init acpi_init(void)
pci_mmcfg_late_init();
acpi_iort_init();
+ acpi_viot_init();
acpi_scan_init();
acpi_ec_init();
acpi_debugfs_init();
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index a184529d8fa4..4af01fddd94c 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -9,6 +9,7 @@
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/acpi_iort.h>
+#include <linux/acpi_viot.h>
#include <linux/signal.h>
#include <linux/kthread.h>
#include <linux/dmi.h>
@@ -1506,12 +1507,17 @@ int acpi_dma_configure_id(struct device *dev, enum
dev_dma_attr attr,
{
const struct iommu_ops *iommu;
u64 dma_addr = 0, size = 0;
+ int ret;
if (attr == DEV_DMA_NOT_SUPPORTED) {
set_dma_ops(dev, &dma_dummy_ops);
return 0;
}
+ ret = acpi_viot_dma_setup(dev, attr);
+ if (ret)
+ return ret > 0 ? 0 : ret;
+
iort_dma_setup(dev, &dma_addr, &size);
iommu = iort_iommu_configure_id(dev, input_id);
diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
new file mode 100644
index 000000000000..57a092e8551b
--- /dev/null
+++ b/drivers/acpi/viot.c
@@ -0,0 +1,406 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Virtual I/O topology
+ */
+#define pr_fmt(fmt) "ACPI: VIOT: " fmt
+
+#include <linux/acpi_viot.h>
+#include <linux/dma-iommu.h>
+#include <linux/dma-map-ops.h>
+#include <linux/fwnode.h>
+#include <linux/iommu.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+struct viot_dev_id {
+ unsigned int type;
+#define VIOT_DEV_TYPE_PCI 1
+#define VIOT_DEV_TYPE_MMIO 2
+ union {
+ /* PCI endpoint or range */
+ struct {
+ u16 segment_start;
+ u16 segment_end;
+ u16 bdf_start;
+ u16 bdf_end;
+ };
+ /* MMIO region */
+ u64 base;
+ };
+};
+
+struct viot_iommu {
+ unsigned int offset;
+ struct viot_dev_id dev_id;
+ struct list_head list;
+
+ struct device *dev; /* transport device */
+ struct iommu_ops *ops;
+ bool static_fwnode;
+};
+
+struct viot_endpoint {
+ struct viot_dev_id dev_id;
+ u32 endpoint_id;
+ struct list_head list;
+ struct viot_iommu *viommu;
+};
+
+static struct acpi_table_viot *viot;
+static LIST_HEAD(viot_iommus);
+static LIST_HEAD(viot_endpoints);
+static DEFINE_MUTEX(viommus_lock);
+
+/*
+ * VIOT parsing functions
+ */
+
+static int __init viot_check_bounds(const struct acpi_viot_header *hdr)
+{
+ struct acpi_viot_header *start, *end, *hdr_end;
+
+ start = ACPI_ADD_PTR(struct acpi_viot_header, viot,
+ max_t(size_t, sizeof(*viot), viot->node_offset));
+ end = ACPI_ADD_PTR(struct acpi_viot_header, viot, viot->header.length);
+ hdr_end = ACPI_ADD_PTR(struct acpi_viot_header, hdr, sizeof(*hdr));
+
+ if (hdr < start || hdr_end > end) {
+ pr_err("Node pointer overflows, bad table\n");
+ return -EOVERFLOW;
+ }
+ if (hdr->length < sizeof(*hdr)) {
+ pr_err("Empty node, bad table\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static struct viot_iommu * __init viot_get_iommu(unsigned int offset)
+{
+ struct viot_iommu *viommu;
+ struct acpi_viot_header *hdr = ACPI_ADD_PTR(struct acpi_viot_header,
+ viot, offset);
+ union {
+ struct acpi_viot_virtio_iommu_pci pci;
+ struct acpi_viot_virtio_iommu_mmio mmio;
+ } *node = (void *)hdr;
+
+ list_for_each_entry(viommu, &viot_iommus, list)
+ if (viommu->offset == offset)
+ return viommu;
+
+ if (viot_check_bounds(hdr))
+ return NULL;
+
+ viommu = kzalloc(sizeof(*viommu), GFP_KERNEL);
+ if (!viommu)
+ return NULL;
+
+ viommu->offset = offset;
+ switch (hdr->type) {
+ case ACPI_VIOT_NODE_VIRTIO_IOMMU_PCI:
+ if (hdr->length < sizeof(node->pci))
+ goto err_free;
+
+ viommu->dev_id.type = VIOT_DEV_TYPE_PCI;
+ viommu->dev_id.segment_start = node->pci.segment;
+ viommu->dev_id.segment_end = node->pci.segment;
+ viommu->dev_id.bdf_start = node->pci.bdf;
+ viommu->dev_id.bdf_end = node->pci.bdf;
+ break;
+ case ACPI_VIOT_NODE_VIRTIO_IOMMU_MMIO:
+ if (hdr->length < sizeof(node->mmio))
+ goto err_free;
+
+ viommu->dev_id.type = VIOT_DEV_TYPE_MMIO;
+ viommu->dev_id.base = node->mmio.base_address;
+ break;
+ default:
+ kfree(viommu);
+ return NULL;
+ }
+
+ list_add(&viommu->list, &viot_iommus);
+ return viommu;
+
+err_free:
+ kfree(viommu);
+ return NULL;
+}
+
+static int __init viot_parse_node(const struct acpi_viot_header *hdr)
+{
+ int ret = -EINVAL;
+ struct viot_endpoint *ep;
+ union {
+ struct acpi_viot_mmio mmio;
+ struct acpi_viot_pci_range pci;
+ } *node = (void *)hdr;
+
+ if (viot_check_bounds(hdr))
+ return -EINVAL;
+
+ if (hdr->type == ACPI_VIOT_NODE_VIRTIO_IOMMU_PCI ||
+ hdr->type == ACPI_VIOT_NODE_VIRTIO_IOMMU_MMIO)
+ return 0;
+
+ ep = kzalloc(sizeof(*ep), GFP_KERNEL);
+ if (!ep)
+ return -ENOMEM;
+
+ switch (hdr->type) {
+ case ACPI_VIOT_NODE_PCI_RANGE:
+ if (hdr->length < sizeof(node->pci))
+ goto err_free;
+
+ ep->dev_id.type = VIOT_DEV_TYPE_PCI;
+ ep->dev_id.segment_start = node->pci.segment_start;
+ ep->dev_id.segment_end = node->pci.segment_end;
+ ep->dev_id.bdf_start = node->pci.bdf_start;
+ ep->dev_id.bdf_end = node->pci.bdf_end;
+ ep->endpoint_id = node->pci.endpoint_start;
+ ep->viommu = viot_get_iommu(node->pci.output_node);
+ break;
+ case ACPI_VIOT_NODE_MMIO:
+ if (hdr->length < sizeof(node->mmio))
+ goto err_free;
+
+ ep->dev_id.type = VIOT_DEV_TYPE_MMIO;
+ ep->dev_id.base = node->mmio.base_address;
+ ep->endpoint_id = node->mmio.endpoint;
+ ep->viommu = viot_get_iommu(node->mmio.output_node);
+ break;
+ default:
+ goto err_free;
+ }
+
+ if (!ep->viommu) {
+ ret = -ENODEV;
+ goto err_free;
+ }
+
+ list_add(&ep->list, &viot_endpoints);
+ return 0;
+
+err_free:
+ kfree(ep);
+ return ret;
+}
+
+void __init acpi_viot_init(void)
+{
+ int i;
+ acpi_status status;
+ struct acpi_table_header *hdr;
+ struct acpi_viot_header *node;
+
+ status = acpi_get_table(ACPI_SIG_VIOT, 0, &hdr);
+ if (ACPI_FAILURE(status)) {
+ if (status != AE_NOT_FOUND) {
+ const char *msg = acpi_format_exception(status);
+
+ pr_err("Failed to get table, %s\n", msg);
+ }
+ return;
+ }
+
+ viot = (void *)hdr;
+
+ node = ACPI_ADD_PTR(struct acpi_viot_header, viot, viot->node_offset);
+ for (i = 0; i < viot->node_count; i++) {
+ if (viot_parse_node(node))
+ return;
+
+ node = ACPI_ADD_PTR(struct acpi_viot_header, node,
+ node->length);
+ }
+}
+
+/*
+ * VIOT access functions
+ */
+
+static bool viot_device_match(struct device *dev, struct viot_dev_id *id,
+ u32 *epid_base)
+{
+ if (id->type == VIOT_DEV_TYPE_PCI && dev_is_pci(dev)) {
+ struct pci_dev *pdev = to_pci_dev(dev);
+ u16 dev_id = pci_dev_id(pdev);
+ u16 domain_nr = pci_domain_nr(pdev->bus);
+
+ if (domain_nr >= id->segment_start &&
+ domain_nr <= id->segment_end &&
+ dev_id >= id->bdf_start &&
+ dev_id <= id->bdf_end) {
+ *epid_base = ((u32)(domain_nr - id->segment_start) << 16) +
+ dev_id - id->bdf_start;
+ return true;
+ }
+ } else if (id->type == VIOT_DEV_TYPE_MMIO && dev_is_platform(dev))
{
+ struct platform_device *plat_dev = to_platform_device(dev);
+ struct resource *mem;
+
+ mem = platform_get_resource(plat_dev, IORESOURCE_MEM, 0);
+ if (mem && mem->start == id->base) {
+ *epid_base = 0;
+ return true;
+ }
+ }
+ return false;
+}
+
+static const struct iommu_ops *viot_iommu_setup(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct viot_iommu *viommu = NULL;
+ struct viot_endpoint *ep;
+ u32 epid;
+ int ret;
+
+ /* Already translated? */
+ if (fwspec && fwspec->ops)
+ return NULL;
+
+ mutex_lock(&viommus_lock);
+ list_for_each_entry(ep, &viot_endpoints, list) {
+ if (viot_device_match(dev, &ep->dev_id, &epid)) {
+ epid += ep->endpoint_id;
+ viommu = ep->viommu;
+ break;
+ }
+ }
+ mutex_unlock(&viommus_lock);
+ if (!viommu)
+ return NULL;
+
+ /* We're not translating ourself */
+ if (viot_device_match(dev, &viommu->dev_id, &epid))
+ return NULL;
+
+ /*
+ * If we found a PCI range managed by the viommu, we're the one that has
+ * to request ACS.
+ */
+ if (dev_is_pci(dev))
+ pci_request_acs();
+
+ if (!viommu->ops || WARN_ON(!viommu->dev))
+ return ERR_PTR(-EPROBE_DEFER);
+
+ ret = iommu_fwspec_init(dev, viommu->dev->fwnode, viommu->ops);
+ if (ret)
+ return ERR_PTR(ret);
+
+ iommu_fwspec_add_ids(dev, &epid, 1);
+
+ /*
+ * If we have reason to believe the IOMMU driver missed the initial
+ * add_device callback for dev, replay it to get things in order.
+ */
+ if (dev->bus && !device_iommu_mapped(dev))
+ iommu_probe_device(dev);
+
+ return viommu->ops;
+}
+
+/**
+ * acpi_viot_dma_setup - Configure DMA for an endpoint described in VIOT
+ * @dev: the endpoint
+ * @attr: coherency property of the endpoint
+ *
+ * Setup the DMA and IOMMU ops for an endpoint described by the VIOT table.
+ *
+ * Return:
+ * * 0 - @dev doesn't match any VIOT node
+ * * 1 - ops for @dev were successfully installed
+ * * -EPROBE_DEFER - ops for @dev aren't yet available
+ */
+int acpi_viot_dma_setup(struct device *dev, enum dev_dma_attr attr)
+{
+ const struct iommu_ops *iommu_ops = viot_iommu_setup(dev);
+
+ if (IS_ERR_OR_NULL(iommu_ops)) {
+ int ret = PTR_ERR(iommu_ops);
+
+ if (ret == -EPROBE_DEFER || ret == 0)
+ return ret;
+ dev_err(dev, "error %d while setting up virt IOMMU\n", ret);
+ return 0;
+ }
+
+#ifdef CONFIG_ARCH_HAS_SETUP_DMA_OPS
+ arch_setup_dma_ops(dev, 0, ~0ULL, iommu_ops, attr == DEV_DMA_COHERENT);
+#else
+ iommu_setup_dma_ops(dev, 0, ~0ULL);
+#endif
+ return 1;
+}
+
+static int viot_set_iommu_ops(struct viot_iommu *viommu, struct device *dev,
+ struct iommu_ops *ops)
+{
+ /*
+ * The IOMMU subsystem relies on fwnode for identifying the IOMMU that
+ * manages an endpoint. Create one if necessary, because PCI devices
+ * don't always get a fwnode.
+ */
+ if (!dev->fwnode) {
+ dev->fwnode = acpi_alloc_fwnode_static();
+ if (!dev->fwnode)
+ return -ENOMEM;
+ viommu->static_fwnode = true;
+ }
+ viommu->dev = dev;
+ viommu->ops = ops;
+
+ return 0;
+}
+
+static int viot_clear_iommu_ops(struct viot_iommu *viommu)
+{
+ struct device *dev = viommu->dev;
+
+ viommu->dev = NULL;
+ viommu->ops = NULL;
+ if (dev && viommu->static_fwnode) {
+ acpi_free_fwnode_static(dev->fwnode);
+ dev->fwnode = NULL;
+ viommu->static_fwnode = false;
+ }
+ return 0;
+}
+
+/**
+ * acpi_viot_set_iommu_ops - Set the IOMMU ops of a virtual IOMMU device
+ * @dev: the IOMMU device (transport)
+ * @ops: the new IOMMU ops or NULL
+ *
+ * Once the IOMMU driver is loaded and the device probed, associate the IOMMU
+ * ops to its VIOT node. Before disabling the IOMMU device, dissociate the ops
+ * from the VIOT node.
+ *
+ * Return 0 on success, an error otherwise
+ */
+int acpi_viot_set_iommu_ops(struct device *dev, struct iommu_ops *ops)
+{
+ int ret = -EINVAL;
+ struct viot_iommu *viommu;
+
+ mutex_lock(&viommus_lock);
+ list_for_each_entry(viommu, &viot_iommus, list) {
+ u32 epid;
+
+ if (!viot_device_match(dev, &viommu->dev_id, &epid))
+ continue;
+
+ if (ops)
+ ret = viot_set_iommu_ops(viommu, dev, ops);
+ else
+ ret = viot_clear_iommu_ops(viommu);
+ break;
+ }
+ mutex_unlock(&viommus_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_viot_set_iommu_ops);
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 2bfdd5734844..054d8405a2db 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -7,6 +7,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/acpi_viot.h>
#include <linux/amba/bus.h>
#include <linux/delay.h>
#include <linux/dma-iommu.h>
@@ -1065,6 +1066,7 @@ static int viommu_probe(struct virtio_device *vdev)
if (ret)
goto err_free_vqs;
+ acpi_viot_set_iommu_ops(parent_dev, &viommu_ops);
iommu_device_set_ops(&viommu->iommu, &viommu_ops);
iommu_device_set_fwnode(&viommu->iommu, parent_dev->fwnode);
@@ -1111,6 +1113,7 @@ static void viommu_remove(struct virtio_device *vdev)
{
struct viommu_dev *viommu = vdev->priv;
+ acpi_viot_set_iommu_ops(vdev->dev.parent, NULL);
iommu_device_sysfs_remove(&viommu->iommu);
iommu_device_unregister(&viommu->iommu);
diff --git a/MAINTAINERS b/MAINTAINERS
index aa84121c5611..799c020fca87 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -432,6 +432,14 @@ W: https://01.org/linux-acpi
B: https://bugzilla.kernel.org
F: drivers/acpi/acpi_video.c
+ACPI VIOT DRIVER
+M: Jean-Philippe Brucker <jean-philippe at linaro.org>
+L: linux-acpi at vger.kernel.org
+L: iommu at lists.linux-foundation.org
+S: Maintained
+F: drivers/acpi/viot.c
+F: include/linux/acpi_viot.h
+
ACPI WMI DRIVER
L: platform-driver-x86 at vger.kernel.org
S: Orphan
--
2.30.2
With the VIOT support in place, x86 platforms can now use the virtio-iommu. The arm64 Kconfig selects IOMMU_DMA, while x86 IOMMU drivers select it themselves. Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org> --- drivers/iommu/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 2819b5c8ec30..ccca83ef2f06 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -400,8 +400,9 @@ config HYPERV_IOMMU config VIRTIO_IOMMU tristate "Virtio IOMMU driver" depends on VIRTIO - depends on ARM64 + depends on (ARM64 || X86) select IOMMU_API + select IOMMU_DMA if X86 select INTERVAL_TREE select ACPI_VIOT if ACPI help -- 2.30.2
Hi Jean, On 3/16/21 8:16 PM, Jean-Philippe Brucker wrote:> Add a driver for the ACPI VIOT table, which enables virtio-iommu on > non-devicetree platforms, including x86. This series depends on the > ACPICA changes of patch 1, which will be included in next release [1] > and pulled into Linux. > > The Virtual I/O Translation table (VIOT) describes the topology of > para-virtual I/O translation devices and the endpoints they manage. > It was recently approved for inclusion into the ACPI standard [2]. > A provisional version of the specification can be found at [3]. > > After discussing non-devicetree support for virtio-iommu at length > [4][5][6] we concluded that it should use this new ACPI table. And for > platforms that don't implement either devicetree or ACPI, a structure > that uses roughly the same format [6] can be built into the device. > > [1] https://github.com/acpica/acpica/pull/666 > [2] https://lore.kernel.org/linux-iommu/20210218233943.GH702808 at redhat.com/ > [3] https://jpbrucker.net/virtio-iommu/viot/viot-v9.pdf > [4] https://lore.kernel.org/linux-iommu/20191122105000.800410-1-jean-philippe at linaro.org/ > [5] https://lore.kernel.org/linux-iommu/20200228172537.377327-1-jean-philippe at linaro.org/ > [6] https://lore.kernel.org/linux-iommu/20200821131540.2801801-1-jean-philippe at linaro.org/Do you have a qemu branch to share for us to start exercising different kinds of topology? Thanks Eric> > Jean-Philippe Brucker (3): > ACPICA: iASL: Add definitions for the VIOT table > ACPI: Add driver for the VIOT table > iommu/virtio: Enable x86 support > > drivers/acpi/Kconfig | 3 + > drivers/iommu/Kconfig | 4 +- > drivers/acpi/Makefile | 2 + > include/acpi/actbl3.h | 67 ++++++ > include/linux/acpi_viot.h | 26 +++ > drivers/acpi/bus.c | 2 + > drivers/acpi/scan.c | 6 + > drivers/acpi/viot.c | 406 +++++++++++++++++++++++++++++++++++ > drivers/iommu/virtio-iommu.c | 3 + > MAINTAINERS | 8 + > 10 files changed, 526 insertions(+), 1 deletion(-) > create mode 100644 include/linux/acpi_viot.h > create mode 100644 drivers/acpi/viot.c >