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From:   Si-Wei Liu <si-wei.liu@oracle.com>
To:     mst@redhat.com, jasowang@redhat.com, parav@nvidia.com
Cc:     virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v3 1/4] vdpa: save vdpa_dev_set_config in struct vdpa_device
Date:   Fri, 21 Oct 2022 15:43:54 -0700
Message-Id: <1666392237-4042-2-git-send-email-si-wei.liu@oracle.com>
In-Reply-To: <1666392237-4042-1-git-send-email-si-wei.liu@oracle.com>
References: <1666392237-4042-1-git-send-email-si-wei.liu@oracle.com>
Precedence: bulk

In order to allow live migration orchestration software to export the
initial set of vdpa attributes with which the device was created, it
will be useful if the vdpa tool can report the config on demand with
simple query. This will ease the orchestration software implementation
so that it doesn't have to keep track of vdpa config change, or have
to persist vdpa attributes across failure and recovery, in fear of
being killed due to accidental software error.

This commit attempts to make struct vdpa_device contain the struct
vdpa_dev_set_config, where all config attributes upon vdpa creation
are carried over. Which will be used in subsequent commits.

Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
---
 include/linux/vdpa.h | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 6d0f5e4..9f519a3 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -58,6 +58,16 @@ struct vdpa_vq_state {
 	};
 };
 
+struct vdpa_dev_set_config {
+	u64 device_features;
+	struct {
+		u8 mac[ETH_ALEN];
+		u16 mtu;
+		u16 max_vq_pairs;
+	} net;
+	u64 mask;
+};
+
 struct vdpa_mgmt_dev;
 
 /**
@@ -77,6 +87,8 @@ struct vdpa_vq_state {
  * @nvqs: maximum number of supported virtqueues
  * @mdev: management device pointer; caller must setup when registering device as part
  *	  of dev_add() mgmtdev ops callback before invoking _vdpa_register_device().
+ * @init_cfg: initial device config on vdpa creation; useful when instantiating
+ *            device with identical config is needed, e.g. migration.
  */
 struct vdpa_device {
 	struct device dev;
@@ -91,6 +103,7 @@ struct vdpa_device {
 	struct vdpa_mgmt_dev *mdev;
 	unsigned int ngroups;
 	unsigned int nas;
+	struct vdpa_dev_set_config init_cfg;
 };
 
 /**
@@ -103,16 +116,6 @@ struct vdpa_iova_range {
 	u64 last;
 };
 
-struct vdpa_dev_set_config {
-	u64 device_features;
-	struct {
-		u8 mac[ETH_ALEN];
-		u16 mtu;
-		u16 max_vq_pairs;
-	} net;
-	u64 mask;
-};
-
 /**
  * Corresponding file area for device memory mapping
  * @file: vma->vm_file for the mapping
-- 
1.8.3.1