@@ -1674,7 +1674,10 @@ void dmar_msi_read(int irq, struct msi_msg *msg)
}
struct dmar_fault_info {
- struct work_struct work;
+ union {
+ struct work_struct work;
+ struct list_head backlog_list;
+ };
struct intel_iommu *iommu;
int type;
int pasid;
@@ -1757,12 +1760,58 @@ static int dmar_fault_handle_one(struct dmar_fault_info *info)
return 0;
}
+struct fault_backlog {
+ struct list_head queue;
+ struct mutex lock;
+ bool is_active;
+};
+
+static struct fault_backlog fault_backlog = {
+ .queue = LIST_HEAD_INIT(fault_backlog.queue),
+ .lock = __MUTEX_INITIALIZER(fault_backlog.lock),
+ .is_active = true,
+};
+
+void dmar_process_deferred_faults(void)
+{
+ struct dmar_fault_info *info, *tmp;
+
+ mutex_lock(&fault_backlog.lock);
+ WARN_ON(!fault_backlog.is_active);
+
+ list_for_each_entry_safe(info, tmp, &fault_backlog.queue,
+ backlog_list) {
+ dmar_fault_handle_one(info);
+ list_del(&info->backlog_list);
+ free_dmar_fault_info(info);
+ }
+ fault_backlog.is_active = false;
+ mutex_unlock(&fault_backlog.lock);
+}
+
static void dmar_fault_handle_work(struct work_struct *work)
{
struct dmar_fault_info *info;
info = container_of(work, struct dmar_fault_info, work);
+ if (fault_backlog.is_active) {
+ /* Postpone handling until PCI devices will be
+ * initialized
+ */
+
+ mutex_lock(&fault_backlog.lock);
+ if (!fault_backlog.is_active) {
+ mutex_unlock(&fault_backlog.lock);
+ goto process;
+ }
+
+ list_add(&info->backlog_list, &fault_backlog.queue);
+ mutex_unlock(&fault_backlog.lock);
+ return;
+ }
+
+process:
dmar_fault_handle_one(info);
free_dmar_fault_info(info);
}
@@ -5041,6 +5041,7 @@ int __init intel_iommu_init(void)
iommu_disable_protect_mem_regions(iommu);
}
pr_info("Intel(R) Virtualization Technology for Directed I/O\n");
+ dmar_process_deferred_faults();
intel_iommu_enabled = 1;
intel_iommu_debugfs_init();
@@ -649,6 +649,7 @@ extern void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 pfsid,
extern int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu);
extern int dmar_ir_support(void);
+extern void dmar_process_deferred_faults(void);
void *alloc_pgtable_page(int node);
void free_pgtable_page(void *vaddr);
First dmar faults can happen even before linux have scanned PCI bus. In such case worker will not have chance to lookup a corresponding 'struct pci_dev'. This commit defers processing of the fault until intel_iommu_init function has been called. At this point of time pci devices will be already initialized. Signed-off-by: Yuri Volchkov <volchkov@amazon.de> --- drivers/iommu/dmar.c | 51 ++++++++++++++++++++++++++++++++++++- drivers/iommu/intel-iommu.c | 1 + include/linux/intel-iommu.h | 1 + 3 files changed, 52 insertions(+), 1 deletion(-)