qemu-kvm/kvm-vfio-ap-Make-vfio-cdev-pre-openable-by-passing-a-fil.patch

From db09b7c60c01ee75d602261ee959a96fa0d89d68 Mon Sep 17 00:00:00 2001
From: Zhenzhong Duan <zhenzhong.duan@intel.com>
Date: Tue, 21 Nov 2023 16:44:14 +0800
Subject: [PATCH 035/101] vfio/ap: Make vfio cdev pre-openable by passing a
 file handle
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RH-Author: Eric Auger <eric.auger@redhat.com>
RH-MergeRequest: 211: IOMMUFD backend backport
RH-Jira: RHEL-19302 RHEL-21057
RH-Acked-by: Cédric Le Goater <clg@redhat.com>
RH-Acked-by: Sebastian Ott <sebott@redhat.com>
RH-Commit: [34/67] aaafa6088a9b0302d53aa539f67792d02ea0f663 (eauger1/centos-qemu-kvm)

This gives management tools like libvirt a chance to open the vfio
cdev with privilege and pass FD to qemu. This way qemu never needs
to have privilege to open a VFIO or iommu cdev node.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
(cherry picked from commit 5e7ba401b71d18544a3e44b2a58b9e63fd5148d5)
Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/vfio/ap.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 80629609ae..f180e4a32a 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -160,7 +160,10 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
     VFIODevice *vbasedev = &vapdev->vdev;
 
-    vbasedev->name = g_path_get_basename(vbasedev->sysfsdev);
+    if (vfio_device_get_name(vbasedev, errp) < 0) {
+        return;
+    }
+
     vbasedev->ops = &vfio_ap_ops;
     vbasedev->type = VFIO_DEVICE_TYPE_AP;
     vbasedev->dev = dev;
@@ -230,11 +233,28 @@ static const VMStateDescription vfio_ap_vmstate = {
     .unmigratable = 1,
 };
 
+static void vfio_ap_instance_init(Object *obj)
+{
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(obj);
+
+    vapdev->vdev.fd = -1;
+}
+
+#ifdef CONFIG_IOMMUFD
+static void vfio_ap_set_fd(Object *obj, const char *str, Error **errp)
+{
+    vfio_device_set_fd(&VFIO_AP_DEVICE(obj)->vdev, str, errp);
+}
+#endif
+
 static void vfio_ap_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     device_class_set_props(dc, vfio_ap_properties);
+#ifdef CONFIG_IOMMUFD
+    object_class_property_add_str(klass, "fd", NULL, vfio_ap_set_fd);
+#endif
     dc->vmsd = &vfio_ap_vmstate;
     dc->desc = "VFIO-based AP device assignment";
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
@@ -249,6 +269,7 @@ static const TypeInfo vfio_ap_info = {
     .name = TYPE_VFIO_AP_DEVICE,
     .parent = TYPE_AP_DEVICE,
     .instance_size = sizeof(VFIOAPDevice),
+    .instance_init = vfio_ap_instance_init,
     .class_init = vfio_ap_class_init,
 };
 
-- 
2.39.3