The branch main has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=887c0877a642c7427aff0cfd0d844b2711e71e1e
commit 887c0877a642c7427aff0cfd0d844b2711e71e1e
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2024-09-01 14:00:36 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2024-09-01 14:03:16 +0000
vmm: Use an sx lock for vmmdev_mtx
This will make it easier to atomically create the device file and set
its si_drv1 member.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D46487
---
sys/dev/vmm/vmm_dev.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/sys/dev/vmm/vmm_dev.c b/sys/dev/vmm/vmm_dev.c
index b4ae2997006f..91d33ccba261 100644
--- a/sys/dev/vmm/vmm_dev.c
+++ b/sys/dev/vmm/vmm_dev.c
@@ -13,9 +13,9 @@
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mman.h>
-#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/queue.h>
+#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/ucred.h>
#include <sys/uio.h>
@@ -63,8 +63,8 @@ struct vmmdev_softc {
static SLIST_HEAD(, vmmdev_softc) head;
static unsigned pr_allow_flag;
-static struct mtx vmmdev_mtx;
-MTX_SYSINIT(vmmdev_mtx, &vmmdev_mtx, "vmm device mutex", MTX_DEF);
+static struct sx vmmdev_mtx;
+SX_SYSINIT(vmmdev_mtx, &vmmdev_mtx, "vmm device mutex");
static MALLOC_DEFINE(M_VMMDEV, "vmmdev", "vmmdev");
@@ -156,7 +156,7 @@ vmmdev_lookup(const char *name, struct ucred *cred)
{
struct vmmdev_softc *sc;
- mtx_assert(&vmmdev_mtx, MA_OWNED);
+ sx_assert(&vmmdev_mtx, SA_XLOCKED);
SLIST_FOREACH(sc, &head, link) {
if (strcmp(name, vm_name(sc->vm)) == 0)
@@ -785,9 +785,9 @@ vmmdev_destroy(struct vmmdev_softc *sc)
crfree(sc->ucred);
if ((sc->flags & VSC_LINKED) != 0) {
- mtx_lock(&vmmdev_mtx);
+ sx_xlock(&vmmdev_mtx);
SLIST_REMOVE(&head, sc, vmmdev_softc, link);
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
}
free(sc, M_VMMDEV);
@@ -799,10 +799,10 @@ vmmdev_lookup_and_destroy(const char *name, struct ucred
*cred)
struct cdev *cdev;
struct vmmdev_softc *sc;
- mtx_lock(&vmmdev_mtx);
+ sx_xlock(&vmmdev_mtx);
sc = vmmdev_lookup(name, cred);
if (sc == NULL || sc->cdev == NULL) {
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
return (EINVAL);
}
@@ -812,7 +812,7 @@ vmmdev_lookup_and_destroy(const char *name, struct ucred
*cred)
*/
cdev = sc->cdev;
sc->cdev = NULL;
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
destroy_dev(cdev);
vmmdev_destroy(sc);
@@ -874,9 +874,9 @@ vmmdev_create(const char *name, struct ucred *cred)
struct vm *vm;
int error;
- mtx_lock(&vmmdev_mtx);
+ sx_xlock(&vmmdev_mtx);
sc = vmmdev_lookup(name, cred);
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
if (sc != NULL)
return (EEXIST);
@@ -890,16 +890,16 @@ vmmdev_create(const char *name, struct ucred *cred)
* Lookup the name again just in case somebody sneaked in when we
* dropped the lock.
*/
- mtx_lock(&vmmdev_mtx);
+ sx_xlock(&vmmdev_mtx);
sc2 = vmmdev_lookup(name, cred);
if (sc2 != NULL) {
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
vmmdev_destroy(sc);
return (EEXIST);
}
sc->flags |= VSC_LINKED;
SLIST_INSERT_HEAD(&head, sc, link);
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
error = make_dev_p(MAKEDEV_CHECKNAME, &cdev, &vmmdevsw, sc->ucred,
UID_ROOT, GID_WHEEL, 0600, "vmm/%s", name);
@@ -908,10 +908,10 @@ vmmdev_create(const char *name, struct ucred *cred)
return (error);
}
- mtx_lock(&vmmdev_mtx);
+ sx_xlock(&vmmdev_mtx);
sc->cdev = cdev;
sc->cdev->si_drv1 = sc;
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
return (0);
}
@@ -1019,10 +1019,10 @@ devmem_create_cdev(struct vmmdev_softc *sc, int segid,
char *devname)
dsc = malloc(sizeof(struct devmem_softc), M_VMMDEV, M_WAITOK | M_ZERO);
- mtx_lock(&vmmdev_mtx);
+ sx_xlock(&vmmdev_mtx);
if (sc->cdev == NULL) {
/* virtual machine is being created or destroyed */
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
free(dsc, M_VMMDEV);
destroy_dev_sched_cb(cdev, NULL, 0);
return (ENODEV);
@@ -1033,7 +1033,7 @@ devmem_create_cdev(struct vmmdev_softc *sc, int segid,
char *devname)
dsc->cdev = cdev;
dsc->sc = sc;
SLIST_INSERT_HEAD(&sc->devmem, dsc, link);
- mtx_unlock(&vmmdev_mtx);
+ sx_xunlock(&vmmdev_mtx);
/* The 'cdev' is ready for use after 'si_drv1' is initialized */
cdev->si_drv1 = dsc;
