Re: [PATCH 6/6] kvm tools: Protect IOPORT tree by rwsem

Pekka Enberg
2011-05-26T16:01:45Z

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