[PATCH RFC 36/39] drivers/xen: xen_shim_domain() support

From: Joao Martins
Date: Wed Feb 20 2019 - 15:20:27 EST


Enable /dev/xen/{gntdev,evtchn} and /proc/xen/ for xen_shim_domain().

These interfaces will be used by xenstored to initialize its
event channel port and the kva used to communicate with the
xenbus driver.

Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
---
drivers/xen/evtchn.c | 4 +++-
drivers/xen/privcmd.c | 5 ++++-
drivers/xen/xenbus/xenbus_xs.c | 2 +-
drivers/xen/xenfs/super.c | 7 ++++---
drivers/xen/xenfs/xensyms.c | 4 ++++
5 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 6d1a5e58968f..367390eb5883 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -708,13 +708,14 @@ static int __init evtchn_init(void)
{
int err;

- if (!xen_domain())
+ if (!xen_domain() && !xen_shim_domain_get())
return -ENODEV;

/* Create '/dev/xen/evtchn'. */
err = misc_register(&evtchn_miscdev);
if (err != 0) {
pr_err("Could not register /dev/xen/evtchn\n");
+ xen_shim_domain_put();
return err;
}

@@ -726,6 +727,7 @@ static int __init evtchn_init(void)
static void __exit evtchn_cleanup(void)
{
misc_deregister(&evtchn_miscdev);
+ xen_shim_domain_put();
}

module_init(evtchn_init);
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index b24ddac1604b..a063ad5c8260 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -999,12 +999,13 @@ static int __init privcmd_init(void)
{
int err;

- if (!xen_domain())
+ if (!xen_domain() && !xen_shim_domain_get())
return -ENODEV;

err = misc_register(&privcmd_dev);
if (err != 0) {
pr_err("Could not register Xen privcmd device\n");
+ xen_shim_domain_put();
return err;
}

@@ -1012,6 +1013,7 @@ static int __init privcmd_init(void)
if (err != 0) {
pr_err("Could not register Xen hypercall-buf device\n");
misc_deregister(&privcmd_dev);
+ xen_shim_domain_put();
return err;
}

@@ -1022,6 +1024,7 @@ static void __exit privcmd_exit(void)
{
misc_deregister(&privcmd_dev);
misc_deregister(&xen_privcmdbuf_dev);
+ xen_shim_domain_put();
}

module_init(privcmd_init);
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index bd6db3703972..062c0a5fa415 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -735,7 +735,7 @@ static void xs_reset_watches(void)
{
int err;

- if (!xen_hvm_domain() || xen_initial_domain())
+ if (!xen_hvm_domain() || xen_initial_domain() || xen_shim_domain())
return;

if (xen_strict_xenbus_quirk())
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index 71ddfb4cf61c..2ef326645880 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -64,7 +64,8 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
};

return simple_fill_super(sb, XENFS_SUPER_MAGIC,
- xen_initial_domain() ? xenfs_init_files : xenfs_files);
+ xen_initial_domain() || xen_shim_domain() ?
+ xenfs_init_files : xenfs_files);
}

static struct dentry *xenfs_mount(struct file_system_type *fs_type,
@@ -84,7 +85,7 @@ MODULE_ALIAS_FS("xenfs");

static int __init xenfs_init(void)
{
- if (xen_domain())
+ if (xen_domain() || xen_shim_domain())
return register_filesystem(&xenfs_type);

return 0;
@@ -92,7 +93,7 @@ static int __init xenfs_init(void)

static void __exit xenfs_exit(void)
{
- if (xen_domain())
+ if (xen_domain() || xen_shim_domain())
unregister_filesystem(&xenfs_type);
}

diff --git a/drivers/xen/xenfs/xensyms.c b/drivers/xen/xenfs/xensyms.c
index c6c73a33c44d..79bccb53d344 100644
--- a/drivers/xen/xenfs/xensyms.c
+++ b/drivers/xen/xenfs/xensyms.c
@@ -8,6 +8,7 @@
#include <xen/interface/platform.h>
#include <asm/xen/hypercall.h>
#include <xen/xen-ops.h>
+#include <xen/xen.h>
#include "xenfs.h"


@@ -114,6 +115,9 @@ static int xensyms_open(struct inode *inode, struct file *file)
struct xensyms *xs;
int ret;

+ if (xen_shim_domain())
+ return -EINVAL;
+
ret = seq_open_private(file, &xensyms_seq_ops,
sizeof(struct xensyms));
if (ret)
--
2.11.0