Re: [PATCH v13 08/24] gunyah: vm_mgr: Introduce basic VM Manager
From: Alex Elder
Date: Mon Jun 05 2023 - 15:49:07 EST
On 5/9/23 3:47 PM, Elliot Berman wrote:
Gunyah VM manager is a kernel moduel which exposes an interface to
Gunyah userspace to load, run, and interact with other Gunyah virtual
machines. The interface is a character device at /dev/gunyah.
Add a basic VM manager driver. Upcoming patches will add more ioctls
into this driver.
Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx>
Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx>
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
I have a couple of comments, but regardless of how you respond
to them:
Reviewed-by: Alex Elder <elder@xxxxxxxxxx>
---
.../userspace-api/ioctl/ioctl-number.rst | 1 +
drivers/virt/gunyah/Makefile | 2 +-
drivers/virt/gunyah/rsc_mgr.c | 50 +++++++++-
drivers/virt/gunyah/vm_mgr.c | 93 +++++++++++++++++++
drivers/virt/gunyah/vm_mgr.h | 20 ++++
include/uapi/linux/gunyah.h | 23 +++++
6 files changed, 187 insertions(+), 2 deletions(-)
create mode 100644 drivers/virt/gunyah/vm_mgr.c
create mode 100644 drivers/virt/gunyah/vm_mgr.h
create mode 100644 include/uapi/linux/gunyah.h
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 176e8fc3f31b..396212e88f7d 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -137,6 +137,7 @@ Code Seq# Include File Comments
'F' DD video/sstfb.h conflict!
'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict!
'G' 00-0F xen/gntalloc.h, xen/gntdev.h conflict!
+'G' 00-0f linux/gunyah.h conflict!
The existing pattern throughout this file is to use capital A-F,
so I would follow that here.
Sort off related: I prefer lower-case a-f in hexadecimal
numbers in code, and you use capitals (at least some of the
time).
'H' 00-7F linux/hiddev.h conflict!
'H' 00-0F linux/hidraw.h conflict!
'H' 01 linux/mei.h conflict!
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index 241bab357b86..e47e25895299 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -1,4 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
-gunyah-y += rsc_mgr.o rsc_mgr_rpc.o
+gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o
obj-$(CONFIG_GUNYAH) += gunyah.o
diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
index 88b5beb1ea51..4f6f96bdcf3d 100644
--- a/drivers/virt/gunyah/rsc_mgr.c
+++ b/drivers/virt/gunyah/rsc_mgr.c
@@ -15,8 +15,10 @@
#include <linux/completion.h>
#include <linux/gunyah_rsc_mgr.h>
#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
#include "rsc_mgr.h"
+#include "vm_mgr.h"
#define RM_RPC_API_VERSION_MASK GENMASK(3, 0)
#define RM_RPC_HEADER_WORDS_MASK GENMASK(7, 4)
@@ -130,6 +132,7 @@ struct gh_rm_connection {
* @cache: cache for allocating Tx messages
* @send_lock: synchronization to allow only one request to be sent at a time
* @nh: notifier chain for clients interested in RM notification messages
+ * @miscdev: /dev/gunyah
*/
struct gh_rm {
struct device *dev;
@@ -146,6 +149,8 @@ struct gh_rm {
struct kmem_cache *cache;
struct mutex send_lock;
struct blocking_notifier_head nh;
+
+ struct miscdevice miscdev;
};
/**
@@ -581,6 +586,33 @@ int gh_rm_notifier_unregister(struct gh_rm *rm, struct notifier_block *nb)
}
EXPORT_SYMBOL_GPL(gh_rm_notifier_unregister);
+struct device *gh_rm_get(struct gh_rm *rm)
+{
+ return get_device(rm->miscdev.this_device);
+}
+EXPORT_SYMBOL_GPL(gh_rm_get);
+
+void gh_rm_put(struct gh_rm *rm)
+{
+ put_device(rm->miscdev.this_device);
+}
+EXPORT_SYMBOL_GPL(gh_rm_put);
+
+static long gh_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct miscdevice *miscdev = filp->private_data;
+ struct gh_rm *rm = container_of(miscdev, struct gh_rm, miscdev);
+
+ return gh_dev_vm_mgr_ioctl(rm, cmd, arg);
+}
+
+static const struct file_operations gh_dev_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = gh_dev_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
+ .llseek = noop_llseek,
+};
+
static int gh_msgq_platform_probe_direction(struct platform_device *pdev, bool tx,
struct gh_resource *ghrsc)
{
@@ -665,7 +697,22 @@ static int gh_rm_drv_probe(struct platform_device *pdev)
rm->msgq_client.rx_callback = gh_rm_msgq_rx_data;
rm->msgq_client.tx_done = gh_rm_msgq_tx_done;
- return gh_msgq_init(&pdev->dev, &rm->msgq, &rm->msgq_client, &rm->tx_ghrsc, &rm->rx_ghrsc);
+ ret = gh_msgq_init(&pdev->dev, &rm->msgq, &rm->msgq_client, &rm->tx_ghrsc, &rm->rx_ghrsc);
+ if (ret)
+ goto err_cache;
+
+ rm->miscdev.name = "gunyah";
+ rm->miscdev.minor = MISC_DYNAMIC_MINOR;
+ rm->miscdev.fops = &gh_dev_fops;
+
+ ret = misc_register(&rm->miscdev);
+ if (ret)
+ goto err_msgq;
+
+ return 0;
+err_msgq:
+ mbox_free_channel(gh_msgq_chan(&rm->msgq));
I'm sure I've said this before. I find it strange that you need
to call mbox_free_channel() here, when it's not obvious where the
client got bound to any mbox channel. It seems like freeing the
channel should happen inside gh_msgq_remove(). But... perhaps
you previously explained to me why it's done this way.
+ gh_msgq_remove(&rm->msgq);
err_cache:
kmem_cache_destroy(rm->cache);
return ret;
@@ -675,6 +722,7 @@ static int gh_rm_drv_remove(struct platform_device *pdev)
{
struct gh_rm *rm = platform_get_drvdata(pdev);
+ misc_deregister(&rm->miscdev);
mbox_free_channel(gh_msgq_chan(&rm->msgq));
gh_msgq_remove(&rm->msgq);
kmem_cache_destroy(rm->cache);
. . .