| Message ID | 1495656803-28011-3-git-send-email-eric.auger@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 24 May 2017 22:13:15 +0200 Eric Auger <eric.auger@redhat.com> wrote: > We add two new fields in vfio_platform_irq: deoi and handler. > > If deoi is set, this means the physical IRQ attached to the virtual > IRQ is directly deactivated by the guest and the VFIO driver does > not need to disable the physical IRQ and mask it at VFIO level. > > The handler pointer points to either the automasked or "deoi" handler. > This latter is the same as the one used for edge sensitive IRQs. > A wrapper handler is introduced that calls the chosen handler function. > > The irq lock is taken/released in the wrapper handler. eventfd_signal > can be called in regions not allowed to sleep. > > Signed-off-by: Eric Auger <eric.auger@redhat.com> > > --- > --- > drivers/vfio/platform/vfio_platform_irq.c | 24 +++++++++++++++++------- > drivers/vfio/platform/vfio_platform_private.h | 2 ++ > 2 files changed, 19 insertions(+), 7 deletions(-) > > diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c > index 831f0b0..2f82459 100644 > --- a/drivers/vfio/platform/vfio_platform_irq.c > +++ b/drivers/vfio/platform/vfio_platform_irq.c > @@ -148,11 +148,8 @@ static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev, > static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id) > { > struct vfio_platform_irq *irq_ctx = dev_id; > - unsigned long flags; > int ret = IRQ_NONE; > > - spin_lock_irqsave(&irq_ctx->lock, flags); > - > if (!irq_ctx->masked && !irq_ctx->automasked) { > ret = IRQ_HANDLED; > > @@ -161,8 +158,6 @@ static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id) > irq_ctx->automasked = true; > } > > - spin_unlock_irqrestore(&irq_ctx->lock, flags); > - > if (ret == IRQ_HANDLED) > eventfd_signal(irq_ctx->trigger, 1); > > @@ -178,6 +173,19 @@ static irqreturn_t vfio_irq_handler(int irq, void *dev_id) > return IRQ_HANDLED; > } > > +static irqreturn_t vfio_wrapper_handler(int irq, void *dev_id) > +{ > + struct vfio_platform_irq *irq_ctx = dev_id; > + unsigned long flags; > + irqreturn_t ret; > + > + spin_lock_irqsave(&irq_ctx->lock, flags); > + ret = irq_ctx->handler(irq, dev_id); > + spin_unlock_irqrestore(&irq_ctx->lock, flags); > + > + return ret; > +} > + > static int vfio_set_trigger(struct vfio_platform_device *vdev, int index, > int fd, irq_handler_t handler) > { > @@ -208,9 +216,10 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index, > } > > irq->trigger = trigger; > + irq->handler = handler; > > irq_set_status_flags(irq->hwirq, IRQ_NOAUTOEN); > - ret = request_irq(irq->hwirq, handler, 0, irq->name, irq); > + ret = request_irq(irq->hwirq, vfio_wrapper_handler, 0, irq->name, irq); Noting here that vfio-platform already requests an exclusive interrupt (flags = 0), which I think is something that's going to need work for vfio-pci since we'll request a shared interrupt by default if the device supports DisINTx masking. If we're doing this special trick at the GIC, we'll starve other devices if they share an interrupt. > if (ret) { > kfree(irq->name); > eventfd_ctx_put(trigger); > @@ -232,7 +241,8 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev, > struct vfio_platform_irq *irq = &vdev->irqs[index]; > irq_handler_t handler; > > - if (vdev->irqs[index].flags & VFIO_IRQ_INFO_AUTOMASKED) > + if (vdev->irqs[index].flags & VFIO_IRQ_INFO_AUTOMASKED && > + !irq->deoi) nit, strange linewrap > handler = vfio_automasked_irq_handler; > else > handler = vfio_irq_handler; > diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h > index 8a3cfa9..b80a380 100644 > --- a/drivers/vfio/platform/vfio_platform_private.h > +++ b/drivers/vfio/platform/vfio_platform_private.h > @@ -38,6 +38,8 @@ struct vfio_platform_irq { > spinlock_t lock; > struct virqfd *unmask; > struct virqfd *mask; > + bool deoi; > + irqreturn_t (*handler)(int irq, void *dev_id); > }; > > struct vfio_platform_region {
diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c index 831f0b0..2f82459 100644 --- a/drivers/vfio/platform/vfio_platform_irq.c +++ b/drivers/vfio/platform/vfio_platform_irq.c @@ -148,11 +148,8 @@ static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev, static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id) { struct vfio_platform_irq *irq_ctx = dev_id; - unsigned long flags; int ret = IRQ_NONE; - spin_lock_irqsave(&irq_ctx->lock, flags); - if (!irq_ctx->masked && !irq_ctx->automasked) { ret = IRQ_HANDLED; @@ -161,8 +158,6 @@ static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id) irq_ctx->automasked = true; } - spin_unlock_irqrestore(&irq_ctx->lock, flags); - if (ret == IRQ_HANDLED) eventfd_signal(irq_ctx->trigger, 1); @@ -178,6 +173,19 @@ static irqreturn_t vfio_irq_handler(int irq, void *dev_id) return IRQ_HANDLED; } +static irqreturn_t vfio_wrapper_handler(int irq, void *dev_id) +{ + struct vfio_platform_irq *irq_ctx = dev_id; + unsigned long flags; + irqreturn_t ret; + + spin_lock_irqsave(&irq_ctx->lock, flags); + ret = irq_ctx->handler(irq, dev_id); + spin_unlock_irqrestore(&irq_ctx->lock, flags); + + return ret; +} + static int vfio_set_trigger(struct vfio_platform_device *vdev, int index, int fd, irq_handler_t handler) { @@ -208,9 +216,10 @@ static int vfio_set_trigger(struct vfio_platform_device *vdev, int index, } irq->trigger = trigger; + irq->handler = handler; irq_set_status_flags(irq->hwirq, IRQ_NOAUTOEN); - ret = request_irq(irq->hwirq, handler, 0, irq->name, irq); + ret = request_irq(irq->hwirq, vfio_wrapper_handler, 0, irq->name, irq); if (ret) { kfree(irq->name); eventfd_ctx_put(trigger); @@ -232,7 +241,8 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev, struct vfio_platform_irq *irq = &vdev->irqs[index]; irq_handler_t handler; - if (vdev->irqs[index].flags & VFIO_IRQ_INFO_AUTOMASKED) + if (vdev->irqs[index].flags & VFIO_IRQ_INFO_AUTOMASKED && + !irq->deoi) handler = vfio_automasked_irq_handler; else handler = vfio_irq_handler; diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h index 8a3cfa9..b80a380 100644 --- a/drivers/vfio/platform/vfio_platform_private.h +++ b/drivers/vfio/platform/vfio_platform_private.h @@ -38,6 +38,8 @@ struct vfio_platform_irq { spinlock_t lock; struct virqfd *unmask; struct virqfd *mask; + bool deoi; + irqreturn_t (*handler)(int irq, void *dev_id); }; struct vfio_platform_region {
We add two new fields in vfio_platform_irq: deoi and handler. If deoi is set, this means the physical IRQ attached to the virtual IRQ is directly deactivated by the guest and the VFIO driver does not need to disable the physical IRQ and mask it at VFIO level. The handler pointer points to either the automasked or "deoi" handler. This latter is the same as the one used for edge sensitive IRQs. A wrapper handler is introduced that calls the chosen handler function. The irq lock is taken/released in the wrapper handler. eventfd_signal can be called in regions not allowed to sleep. Signed-off-by: Eric Auger <eric.auger@redhat.com> --- --- drivers/vfio/platform/vfio_platform_irq.c | 24 +++++++++++++++++------- drivers/vfio/platform/vfio_platform_private.h | 2 ++ 2 files changed, 19 insertions(+), 7 deletions(-)