[Qemu-devel] [Resend RFC PATCH 4/4] VFIO: Read IOMMU fault info from kernel space when get fault event

[Lan Tianyu]

This patch is to implement fault event handler with new vfio cmd to
get fault info and notify vIOMMU device model.

Signed-off-by: Lan Tianyu <address@hidden>
---
 hw/vfio/common.c           | 51 ++++++++++++++++++++++++++++++++++++++++++++++
 linux-headers/linux/vfio.h | 22 ++++++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 628b424..4f76e26 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -297,6 +297,57 @@ static bool 
vfio_listener_skipped_section(MemoryRegionSection *section)
 
 static void vfio_iommu_fault(void *opaque)
 {
+    VFIOContainer *container = opaque;
+    struct vfio_iommu_type1_get_fault_info *info;
+    struct vfio_iommu_fault_info *fault_info;
+    MemoryRegion *mr = container->space->as->root;
+    int count = 0, i, ret;
+    IOMMUFaultInfo tmp;
+
+    if (!event_notifier_test_and_clear(&container->fault_notifier)) {
+        return;
+    }
+
+    info = g_malloc0(sizeof(*info));
+    if (!info) {
+        error_report("vfio: Fail to allocate memory");
+        return;
+    }
+
+    info->argsz = sizeof(*info);
+
+    ret = ioctl(container->fd, VFIO_IOMMU_GET_FAULT_INFO, info);
+    if (ret && ret != -ENOSPC) {
+        error_report("vfio: Can't get fault info");
+        goto err_exit;
+    }
+
+    count = info->count;
+    if (count <= 0) {
+        goto err_exit;
+    }
+
+    info = g_realloc(info, sizeof(*info) + count * sizeof(*fault_info));
+    info->argsz = sizeof(*info) + count * sizeof(*fault_info);
+    fault_info = info->fault_info;
+
+    ret = ioctl(container->fd, VFIO_IOMMU_GET_FAULT_INFO, info);
+    if (ret) {
+        error_report("vfio: Can't get fault info");
+        goto err_exit;
+    }
+
+    for (i = 0; i < info->count; i++) {
+        tmp.addr = fault_info[i].addr;
+        tmp.sid = fault_info[i].sid;
+        tmp.fault_reason = fault_info[i].fault_reason;
+        tmp.is_write = fault_info[i].is_write;
+
+        memory_region_iommu_fault_notify(mr, &tmp);
+    }
+
+err_exit:
+    g_free(info);
 }
 
 static int vfio_set_iommu_fault_notifier(struct VFIOContainer *container)
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index ca890ee..8b172f5 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -550,6 +550,28 @@ struct vfio_iommu_type1_set_fault_eventfd {
 
 #define VFIO_IOMMU_SET_FAULT_EVENTFD   _IO(VFIO_TYPE, VFIO_BASE + 17)
 
+/*
+ * VFIO_IOMMU_GET_FAULT_INFO           _IO(VFIO_TYPE, VFIO_BASE + 18)
+ *
+ * Return IOMMU fault info to userspace.
+ */
+
+struct vfio_iommu_fault_info {
+       __u64   addr;
+       __u16   sid;
+       __u8    fault_reason;
+       __u8    is_write:1;
+};
+
+struct vfio_iommu_type1_get_fault_info {
+       __u32   argsz;
+       __u32   flags;
+       __u32   count;
+       struct vfio_iommu_fault_info fault_info[];
+};
+
+#define VFIO_IOMMU_GET_FAULT_INFO      _IO(VFIO_TYPE, VFIO_BASE + 18)
+
 /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
 
 /*
-- 
1.8.3.1