[RFC,v5,10/23] vfio-user: get device info

Commit Message

John Johnson May 5, 2022, 5:19 p.m. UTC

Signed-off-by: Elena Ufimtseva <[e-mail]>
Signed-off-by: John G Johnson <[e-mail]>
Signed-off-by: Jagannathan Raman <[e-mail]>
---
 hw/vfio/user-protocol.h | 14 +++++++++++++
 hw/vfio/user.h          |  2 ++
 hw/vfio/pci.c           | 26 ++++++++++++++++++++++++
 hw/vfio/user.c          | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+)

Patch

diff --git a/hw/vfio/user-protocol.h b/hw/vfio/user-protocol.h
index a0889f6..4ad8f45 100644
--- a/hw/vfio/user-protocol.h
+++ b/hw/vfio/user-protocol.h
@@ -92,4 +92,18 @@  typedef struct {
 #define VFIO_USER_DEF_MAX_XFER  (1024 * 1024)
 #define VFIO_USER_MAX_MAX_XFER  (64 * 1024 * 1024)
 
+
+/*
+ * VFIO_USER_DEVICE_GET_INFO
+ * imported from struct_device_info
+ */
+typedef struct {
+    VFIOUserHdr hdr;
+    uint32_t argsz;
+    uint32_t flags;
+    uint32_t num_regions;
+    uint32_t num_irqs;
+    uint32_t cap_offset;
+} VFIOUserDeviceInfo;
+
 #endif /* VFIO_USER_PROTOCOL_H */
diff --git a/hw/vfio/user.h b/hw/vfio/user.h
index 00d21bf..633b3ea 100644
--- a/hw/vfio/user.h
+++ b/hw/vfio/user.h
@@ -85,4 +85,6 @@  void vfio_user_set_handler(VFIODevice *vbasedev,
                            void *reqarg);
 int vfio_user_validate_version(VFIODevice *vbasedev, Error **errp);
 
+extern VFIODevIO vfio_dev_io_sock;
+
 #endif /* VFIO_USER_H */
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 7e5b910..68d6f0c 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3416,6 +3416,8 @@  static void vfio_user_pci_realize(PCIDevice *pdev, Error **errp)
     VFIODevice *vbasedev = &vdev->vbasedev;
     SocketAddress addr;
     VFIOProxy *proxy;
+    struct vfio_device_info info;
+    int ret;
     Error *err = NULL;
 
     /*
@@ -3455,6 +3457,30 @@  static void vfio_user_pci_realize(PCIDevice *pdev, Error **errp)
     vbasedev->fd = -1;
     vbasedev->type = VFIO_DEVICE_TYPE_PCI;
     vbasedev->ops = &vfio_user_pci_ops;
+    vbasedev->io_ops = &vfio_dev_io_sock;
+
+    ret = VDEV_GET_INFO(vbasedev, &info);
+    if (ret) {
+        error_setg_errno(errp, -ret, "get info failure");
+        goto error;
+    }
+    /* must be PCI */
+    if ((info.flags & VFIO_DEVICE_FLAGS_PCI) == 0) {
+        error_setg(errp, "remote device not PCI");
+        goto error;
+    }
+
+    vbasedev->num_irqs = info.num_irqs;
+    vbasedev->num_regions = info.num_regions;
+    vbasedev->flags = info.flags;
+    vbasedev->reset_works = !!(info.flags & VFIO_DEVICE_FLAGS_RESET);
+
+    vfio_get_all_regions(vbasedev);
+    vfio_populate_device(vdev, &err);
+    if (err) {
+        error_propagate(errp, err);
+        goto error;
+    }
 
     return;
 
diff --git a/hw/vfio/user.c b/hw/vfio/user.c
index dc3f1a6..51e23dd 100644
--- a/hw/vfio/user.c
+++ b/hw/vfio/user.c
@@ -30,6 +30,13 @@ 
 #include "qapi/qmp/qnum.h"
 #include "user.h"
 
+/*
+ * These are to defend against a malign server trying
+ * to force us to run out of memory.
+ */
+#define VFIO_USER_MAX_REGIONS   100
+#define VFIO_USER_MAX_IRQS      50
+
 static uint64_t max_xfer_size = VFIO_USER_DEF_MAX_XFER;
 static uint64_t max_send_fds = VFIO_USER_DEF_MAX_FDS;
 static int wait_time = 1000;   /* wait 1 sec for replies */
@@ -984,3 +991,50 @@  int vfio_user_validate_version(VFIODevice *vbasedev, Error **errp)
 
     return 0;
 }
+
+static int vfio_user_get_info(VFIOProxy *proxy, struct vfio_device_info *info)
+{
+    VFIOUserDeviceInfo msg;
+
+    memset(&msg, 0, sizeof(msg));
+    vfio_user_request_msg(&msg.hdr, VFIO_USER_DEVICE_GET_INFO, sizeof(msg), 0);
+    msg.argsz = sizeof(struct vfio_device_info);
+
+    vfio_user_send_wait(proxy, &msg.hdr, NULL, 0, false);
+    if (msg.hdr.flags & VFIO_USER_ERROR) {
+        return -msg.hdr.error_reply;
+    }
+
+    memcpy(info, &msg.argsz, sizeof(*info));
+    return 0;
+}
+
+
+/*
+ * Socket-based io_ops
+ */
+
+static int vfio_user_io_get_info(VFIODevice *vbasedev,
+                                 struct vfio_device_info *info)
+{
+    int ret;
+
+    ret = vfio_user_get_info(vbasedev->proxy, info);
+    if (ret) {
+        return ret;
+    }
+
+    /* defend against a malicious server */
+    if (info->num_regions > VFIO_USER_MAX_REGIONS ||
+        info->num_irqs > VFIO_USER_MAX_IRQS) {
+        error_printf("vfio_user_get_info: invalid reply\n");
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+VFIODevIO vfio_dev_io_sock = {
+    .get_info = vfio_user_io_get_info,
+};
+