* [PATCH] KVM: Add reading critical region for kvm_io_bus_read/write
@ 2010-12-06 8:44 Sheng Yang
2010-12-06 12:58 ` Avi Kivity
0 siblings, 1 reply; 3+ messages in thread
From: Sheng Yang @ 2010-12-06 8:44 UTC (permalink / raw)
To: Avi Kivity, Marcelo Tosatti; +Cc: kvm, Sheng Yang
Seems we missed it.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
Do we need this, or slot_lock covered this?
virt/kvm/kvm_main.c | 24 ++++++++++++++++--------
1 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c4ee364..3e71b91 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2228,28 +2228,36 @@ static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int len, const void *val)
{
- int i;
+ int i, idx, r = -EOPNOTSUPP;
struct kvm_io_bus *bus;
+ idx = srcu_read_lock(&kvm->srcu);
bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
for (i = 0; i < bus->dev_count; i++)
- if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
- return 0;
- return -EOPNOTSUPP;
+ if (!kvm_iodevice_write(bus->devs[i], addr, len, val)) {
+ r = 0;
+ break;
+ }
+ srcu_read_unlock(&kvm->srcu, idx);
+ return r;
}
/* kvm_io_bus_read - called under kvm->slots_lock */
int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int len, void *val)
{
- int i;
+ int i, idx, r = -EOPNOTSUPP;
struct kvm_io_bus *bus;
+ idx = srcu_read_lock(&kvm->srcu);
bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
for (i = 0; i < bus->dev_count; i++)
- if (!kvm_iodevice_read(bus->devs[i], addr, len, val))
- return 0;
- return -EOPNOTSUPP;
+ if (!kvm_iodevice_read(bus->devs[i], addr, len, val)) {
+ r = 0;
+ break;
+ }
+ srcu_read_unlock(&kvm->srcu, idx);
+ return r;
}
/* Caller must hold slots_lock. */
--
1.7.0.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] KVM: Add reading critical region for kvm_io_bus_read/write
2010-12-06 8:44 [PATCH] KVM: Add reading critical region for kvm_io_bus_read/write Sheng Yang
@ 2010-12-06 12:58 ` Avi Kivity
2010-12-07 2:35 ` Sheng Yang
0 siblings, 1 reply; 3+ messages in thread
From: Avi Kivity @ 2010-12-06 12:58 UTC (permalink / raw)
To: Sheng Yang; +Cc: Marcelo Tosatti, kvm
On 12/06/2010 10:44 AM, Sheng Yang wrote:
> Seems we missed it.
>
> Signed-off-by: Sheng Yang<sheng@linux.intel.com>
> ---
> Do we need this, or slot_lock covered this?
>
> virt/kvm/kvm_main.c | 24 ++++++++++++++++--------
> 1 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index c4ee364..3e71b91 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2228,28 +2228,36 @@ static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
> int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> int len, const void *val)
> {
> - int i;
> + int i, idx, r = -EOPNOTSUPP;
> struct kvm_io_bus *bus;
>
> + idx = srcu_read_lock(&kvm->srcu);
> bus = srcu_dereference(kvm->buses[bus_idx],&kvm->srcu);
> for (i = 0; i< bus->dev_count; i++)
> - if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
> - return 0;
> - return -EOPNOTSUPP;
> + if (!kvm_iodevice_write(bus->devs[i], addr, len, val)) {
> + r = 0;
> + break;
> + }
> + srcu_read_unlock(&kvm->srcu, idx);
> + return r;
> }
Isn't this already taken care of by srcu_read_lock() in
vcpu_enter_guest(), just before calling ->handle_exit()?
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] KVM: Add reading critical region for kvm_io_bus_read/write
2010-12-06 12:58 ` Avi Kivity
@ 2010-12-07 2:35 ` Sheng Yang
0 siblings, 0 replies; 3+ messages in thread
From: Sheng Yang @ 2010-12-07 2:35 UTC (permalink / raw)
To: Avi Kivity; +Cc: Marcelo Tosatti, kvm
On Monday 06 December 2010 20:58:10 Avi Kivity wrote:
> On 12/06/2010 10:44 AM, Sheng Yang wrote:
> > Seems we missed it.
> >
> > Signed-off-by: Sheng Yang<sheng@linux.intel.com>
> > ---
> > Do we need this, or slot_lock covered this?
> >
> > virt/kvm/kvm_main.c | 24 ++++++++++++++++--------
> > 1 files changed, 16 insertions(+), 8 deletions(-)
> >
> > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > index c4ee364..3e71b91 100644
> > --- a/virt/kvm/kvm_main.c
> > +++ b/virt/kvm/kvm_main.c
> > @@ -2228,28 +2228,36 @@ static void kvm_io_bus_destroy(struct kvm_io_bus
> > *bus)
> >
> > int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> >
> > int len, const void *val)
> >
> > {
> >
> > - int i;
> > + int i, idx, r = -EOPNOTSUPP;
> >
> > struct kvm_io_bus *bus;
> >
> > + idx = srcu_read_lock(&kvm->srcu);
> >
> > bus = srcu_dereference(kvm->buses[bus_idx],&kvm->srcu);
> > for (i = 0; i< bus->dev_count; i++)
> >
> > - if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
> > - return 0;
> > - return -EOPNOTSUPP;
> > + if (!kvm_iodevice_write(bus->devs[i], addr, len, val)) {
> > + r = 0;
> > + break;
> > + }
> > + srcu_read_unlock(&kvm->srcu, idx);
> > + return r;
> >
> > }
>
> Isn't this already taken care of by srcu_read_lock() in
> vcpu_enter_guest(), just before calling ->handle_exit()?
Yes, finally found it. So big reading critical region...
--
regards
Yang, Sheng
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-12-07 2:32 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-12-06 8:44 [PATCH] KVM: Add reading critical region for kvm_io_bus_read/write Sheng Yang
2010-12-06 12:58 ` Avi Kivity
2010-12-07 2:35 ` Sheng Yang
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox