linux-kernel - [PATCH v3 2/5] vhost-vdpa: reset vendor specific mapping to initial state in .release

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 18 Oct 2023 18:10:15 -0700
From:   Si-Wei Liu <si-wei.liu@...cle.com>
To:     jasowang@...hat.com, mst@...hat.com, eperezma@...hat.com,
        sgarzare@...hat.com, dtatulea@...dia.com
Cc:     virtualization@...ts.linux-foundation.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 2/5] vhost-vdpa: reset vendor specific mapping to initial state in .release

Devices with on-chip IOMMU or vendor specific IOTLB implementation
may need to restore iotlb mapping to the initial or default state
using the .reset_map op, as it's desirable for some parent devices
to solely manipulate mappings by its own, independent of virtio device
state. For instance, device reset does not cause mapping go away on
such IOTLB model in need of persistent mapping. Before vhost-vdpa
is going away, give them a chance to reset iotlb back to the initial
state in vhost_vdpa_cleanup().

Signed-off-by: Si-Wei Liu <si-wei.liu@...cle.com>
Acked-by: Eugenio Pérez <eperezma@...hat.com>
---
 drivers/vhost/vdpa.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 851535f57b95..a3f8160c9807 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -131,6 +131,15 @@ static struct vhost_vdpa_as *vhost_vdpa_find_alloc_as(struct vhost_vdpa *v,
 	return vhost_vdpa_alloc_as(v, asid);
 }
 
+static void vhost_vdpa_reset_map(struct vhost_vdpa *v, u32 asid)
+{
+	struct vdpa_device *vdpa = v->vdpa;
+	const struct vdpa_config_ops *ops = vdpa->config;
+
+	if (ops->reset_map)
+		ops->reset_map(vdpa, asid);
+}
+
 static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
 {
 	struct vhost_vdpa_as *as = asid_to_as(v, asid);
@@ -140,6 +149,13 @@ static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
 
 	hlist_del(&as->hash_link);
 	vhost_vdpa_iotlb_unmap(v, &as->iotlb, 0ULL, 0ULL - 1, asid);
+	/*
+	 * Devices with vendor specific IOMMU may need to restore
+	 * iotlb to the initial or default state which is not done
+	 * through device reset, as the IOTLB mapping manipulation
+	 * could be decoupled from the virtio device life cycle.
+	 */
+	vhost_vdpa_reset_map(v, asid);
 	kfree(as);
 
 	return 0;
-- 
2.39.3