| Message ID | 1306419950-19064-6-git-send-email-levinsasha928@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 26 May 2011, Sasha Levin wrote: > Makes ioport thread-safe. > > Signed-off-by: Sasha Levin <levinsasha928@gmail.com> > --- > tools/kvm/ioport.c | 7 +++++++ > 1 files changed, 7 insertions(+), 0 deletions(-) > > diff --git a/tools/kvm/ioport.c b/tools/kvm/ioport.c > index 1f13960..db9ff0f 100644 > --- a/tools/kvm/ioport.c > +++ b/tools/kvm/ioport.c > @@ -3,6 +3,7 @@ > #include "kvm/kvm.h" > #include "kvm/util.h" > #include "kvm/rbtree-interval.h" > +#include "kvm/rwsem.h" > > #include <linux/kvm.h> /* for KVM_EXIT_* */ > #include <linux/types.h> > @@ -22,6 +23,7 @@ struct ioport_entry { > > static struct rb_root ioport_tree = RB_ROOT; > bool ioport_debug; > +static DECLARE_RWSEM(ioport_tree_sem); Why do we need a new lock here? Can't we reuse the new ioport_mutex? Pekka -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2011-05-26 at 19:01 +0300, Pekka Enberg wrote: > On Thu, 26 May 2011, Sasha Levin wrote: > > Makes ioport thread-safe. > > > > Signed-off-by: Sasha Levin <levinsasha928@gmail.com> > > --- > > tools/kvm/ioport.c | 7 +++++++ > > 1 files changed, 7 insertions(+), 0 deletions(-) > > > > diff --git a/tools/kvm/ioport.c b/tools/kvm/ioport.c > > index 1f13960..db9ff0f 100644 > > --- a/tools/kvm/ioport.c > > +++ b/tools/kvm/ioport.c > > @@ -3,6 +3,7 @@ > > #include "kvm/kvm.h" > > #include "kvm/util.h" > > #include "kvm/rbtree-interval.h" > > +#include "kvm/rwsem.h" > > > > #include <linux/kvm.h> /* for KVM_EXIT_* */ > > #include <linux/types.h> > > @@ -22,6 +23,7 @@ struct ioport_entry { > > > > static struct rb_root ioport_tree = RB_ROOT; > > bool ioport_debug; > > +static DECLARE_RWSEM(ioport_tree_sem); > > Why do we need a new lock here? Can't we reuse the new ioport_mutex? ioport_mutex is used for allocations of ioports to devices, this lock is intended to protect the ioport tree from being read while new devices are added.
diff --git a/tools/kvm/ioport.c b/tools/kvm/ioport.c index 1f13960..db9ff0f 100644 --- a/tools/kvm/ioport.c +++ b/tools/kvm/ioport.c @@ -3,6 +3,7 @@ #include "kvm/kvm.h" #include "kvm/util.h" #include "kvm/rbtree-interval.h" +#include "kvm/rwsem.h" #include <linux/kvm.h> /* for KVM_EXIT_* */ #include <linux/types.h> @@ -22,6 +23,7 @@ struct ioport_entry { static struct rb_root ioport_tree = RB_ROOT; bool ioport_debug; +static DECLARE_RWSEM(ioport_tree_sem); static struct ioport_entry *ioport_search(struct rb_root *root, u64 addr) { @@ -71,6 +73,7 @@ void ioport__register(u16 port, struct ioport_operations *ops, int count) { struct ioport_entry *entry; + down_write(&ioport_tree_sem); entry = ioport_search(&ioport_tree, port); if (entry) { pr_warning("ioport re-registered: %x", port); @@ -87,6 +90,8 @@ void ioport__register(u16 port, struct ioport_operations *ops, int count) }; ioport_insert(&ioport_tree, entry); + + up_write(&ioport_tree_sem); } static const char *to_direction(int direction) @@ -108,7 +113,9 @@ bool kvm__emulate_io(struct kvm *kvm, u16 port, void *data, int direction, int s bool ret; struct ioport_entry *entry; + down_read(&ioport_tree_sem); entry = ioport_search(&ioport_tree, port); + up_read(&ioport_tree_sem); if (!entry) goto error;
Makes ioport thread-safe. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> --- tools/kvm/ioport.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-)