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authorLu Baolu <baolu.lu@linux.intel.com>2024-07-02 14:34:41 +0800
committerJason Gunthorpe <jgg@nvidia.com>2024-07-09 13:54:32 -0300
commitb7d8833677baad8c80ed1aac8c396d687e64a376 (patch)
tree211a8df4c1bd11ed6062a2dc7e42bb321f761729 /drivers/iommu/iommufd/fault.c
parent07838f7fd529c8a6de44b601d4b7057e6c8d36ed (diff)
iommufd: Fault-capable hwpt attach/detach/replace
Add iopf-capable hw page table attach/detach/replace helpers. The pointer to iommufd_device is stored in the domain attachment handle, so that it can be echo'ed back in the iopf_group. The iopf-capable hw page tables can only be attached to devices that support the IOMMU_DEV_FEAT_IOPF feature. On the first attachment of an iopf-capable hw_pagetable to the device, the IOPF feature is enabled on the device. Similarly, after the last iopf-capable hwpt is detached from the device, the IOPF feature is disabled on the device. The current implementation allows a replacement between iopf-capable and non-iopf-capable hw page tables. This matches the nested translation use case, where a parent domain is attached by default and can then be replaced with a nested user domain with iopf support. Link: https://lore.kernel.org/r/20240702063444.105814-8-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/iommu/iommufd/fault.c')
-rw-r--r--drivers/iommu/iommufd/fault.c190
1 files changed, 190 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c
index 68ff94671d48..4934ae572638 100644
--- a/drivers/iommu/iommufd/fault.c
+++ b/drivers/iommu/iommufd/fault.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/iommufd.h>
+#include <linux/pci.h>
#include <linux/poll.h>
#include <linux/anon_inodes.h>
#include <uapi/linux/iommufd.h>
@@ -15,6 +16,195 @@
#include "../iommu-priv.h"
#include "iommufd_private.h"
+static int iommufd_fault_iopf_enable(struct iommufd_device *idev)
+{
+ struct device *dev = idev->dev;
+ int ret;
+
+ /*
+ * Once we turn on PCI/PRI support for VF, the response failure code
+ * should not be forwarded to the hardware due to PRI being a shared
+ * resource between PF and VFs. There is no coordination for this
+ * shared capability. This waits for a vPRI reset to recover.
+ */
+ if (dev_is_pci(dev) && to_pci_dev(dev)->is_virtfn)
+ return -EINVAL;
+
+ mutex_lock(&idev->iopf_lock);
+ /* Device iopf has already been on. */
+ if (++idev->iopf_enabled > 1) {
+ mutex_unlock(&idev->iopf_lock);
+ return 0;
+ }
+
+ ret = iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_IOPF);
+ if (ret)
+ --idev->iopf_enabled;
+ mutex_unlock(&idev->iopf_lock);
+
+ return ret;
+}
+
+static void iommufd_fault_iopf_disable(struct iommufd_device *idev)
+{
+ mutex_lock(&idev->iopf_lock);
+ if (!WARN_ON(idev->iopf_enabled == 0)) {
+ if (--idev->iopf_enabled == 0)
+ iommu_dev_disable_feature(idev->dev, IOMMU_DEV_FEAT_IOPF);
+ }
+ mutex_unlock(&idev->iopf_lock);
+}
+
+static int __fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt,
+ struct iommufd_device *idev)
+{
+ struct iommufd_attach_handle *handle;
+ int ret;
+
+ handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+ if (!handle)
+ return -ENOMEM;
+
+ handle->idev = idev;
+ ret = iommu_attach_group_handle(hwpt->domain, idev->igroup->group,
+ &handle->handle);
+ if (ret)
+ kfree(handle);
+
+ return ret;
+}
+
+int iommufd_fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt,
+ struct iommufd_device *idev)
+{
+ int ret;
+
+ if (!hwpt->fault)
+ return -EINVAL;
+
+ ret = iommufd_fault_iopf_enable(idev);
+ if (ret)
+ return ret;
+
+ ret = __fault_domain_attach_dev(hwpt, idev);
+ if (ret)
+ iommufd_fault_iopf_disable(idev);
+
+ return ret;
+}
+
+static void iommufd_auto_response_faults(struct iommufd_hw_pagetable *hwpt,
+ struct iommufd_attach_handle *handle)
+{
+ struct iommufd_fault *fault = hwpt->fault;
+ struct iopf_group *group, *next;
+ unsigned long index;
+
+ if (!fault)
+ return;
+
+ mutex_lock(&fault->mutex);
+ list_for_each_entry_safe(group, next, &fault->deliver, node) {
+ if (group->attach_handle != &handle->handle)
+ continue;
+ list_del(&group->node);
+ iopf_group_response(group, IOMMU_PAGE_RESP_INVALID);
+ iopf_free_group(group);
+ }
+
+ xa_for_each(&fault->response, index, group) {
+ if (group->attach_handle != &handle->handle)
+ continue;
+ xa_erase(&fault->response, index);
+ iopf_group_response(group, IOMMU_PAGE_RESP_INVALID);
+ iopf_free_group(group);
+ }
+ mutex_unlock(&fault->mutex);
+}
+
+static struct iommufd_attach_handle *
+iommufd_device_get_attach_handle(struct iommufd_device *idev)
+{
+ struct iommu_attach_handle *handle;
+
+ handle = iommu_attach_handle_get(idev->igroup->group, IOMMU_NO_PASID, 0);
+ if (!handle)
+ return NULL;
+
+ return to_iommufd_handle(handle);
+}
+
+void iommufd_fault_domain_detach_dev(struct iommufd_hw_pagetable *hwpt,
+ struct iommufd_device *idev)
+{
+ struct iommufd_attach_handle *handle;
+
+ handle = iommufd_device_get_attach_handle(idev);
+ iommu_detach_group_handle(hwpt->domain, idev->igroup->group);
+ iommufd_auto_response_faults(hwpt, handle);
+ iommufd_fault_iopf_disable(idev);
+ kfree(handle);
+}
+
+static int __fault_domain_replace_dev(struct iommufd_device *idev,
+ struct iommufd_hw_pagetable *hwpt,
+ struct iommufd_hw_pagetable *old)
+{
+ struct iommufd_attach_handle *handle, *curr = NULL;
+ int ret;
+
+ if (old->fault)
+ curr = iommufd_device_get_attach_handle(idev);
+
+ if (hwpt->fault) {
+ handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+ if (!handle)
+ return -ENOMEM;
+
+ handle->handle.domain = hwpt->domain;
+ handle->idev = idev;
+ ret = iommu_replace_group_handle(idev->igroup->group,
+ hwpt->domain, &handle->handle);
+ } else {
+ ret = iommu_replace_group_handle(idev->igroup->group,
+ hwpt->domain, NULL);
+ }
+
+ if (!ret && curr) {
+ iommufd_auto_response_faults(old, curr);
+ kfree(curr);
+ }
+
+ return ret;
+}
+
+int iommufd_fault_domain_replace_dev(struct iommufd_device *idev,
+ struct iommufd_hw_pagetable *hwpt,
+ struct iommufd_hw_pagetable *old)
+{
+ bool iopf_off = !hwpt->fault && old->fault;
+ bool iopf_on = hwpt->fault && !old->fault;
+ int ret;
+
+ if (iopf_on) {
+ ret = iommufd_fault_iopf_enable(idev);
+ if (ret)
+ return ret;
+ }
+
+ ret = __fault_domain_replace_dev(idev, hwpt, old);
+ if (ret) {
+ if (iopf_on)
+ iommufd_fault_iopf_disable(idev);
+ return ret;
+ }
+
+ if (iopf_off)
+ iommufd_fault_iopf_disable(idev);
+
+ return 0;
+}
+
void iommufd_fault_destroy(struct iommufd_object *obj)
{
struct iommufd_fault *fault = container_of(obj, struct iommufd_fault, obj);