Virqfd just needs to keep accesses to any struct *virqfd safe, but this
comes into play only when creating or destroying eventfds, so sharing
the same spinlock with the VFIO bus driver is not necessary.
Signed-off-by: Antonios Motakis <[email protected]>
---
drivers/vfio/pci/vfio_pci_intrs.c | 10 +++++-----
drivers/vfio/virqfd.c | 24 +++++++++++++-----------
include/linux/vfio.h | 3 +--
3 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 3f909bb..e56c814 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -226,8 +226,8 @@ static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
static void vfio_intx_disable(struct vfio_pci_device *vdev)
{
vfio_intx_set_signal(vdev, -1);
- virqfd_disable(vdev, &vdev->ctx[0].unmask);
- virqfd_disable(vdev, &vdev->ctx[0].mask);
+ virqfd_disable(&vdev->ctx[0].unmask);
+ virqfd_disable(&vdev->ctx[0].mask);
vdev->irq_type = VFIO_PCI_NUM_IRQS;
vdev->num_ctx = 0;
kfree(vdev->ctx);
@@ -377,8 +377,8 @@ static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
for (i = 0; i < vdev->num_ctx; i++) {
- virqfd_disable(vdev, &vdev->ctx[i].unmask);
- virqfd_disable(vdev, &vdev->ctx[i].mask);
+ virqfd_disable(&vdev->ctx[i].unmask);
+ virqfd_disable(&vdev->ctx[i].mask);
}
if (msix) {
@@ -415,7 +415,7 @@ static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev,
vfio_send_intx_eventfd, NULL,
&vdev->ctx[0].unmask, fd);
- virqfd_disable(vdev, &vdev->ctx[0].unmask);
+ virqfd_disable(&vdev->ctx[0].unmask);
}
return 0;
diff --git a/drivers/vfio/virqfd.c b/drivers/vfio/virqfd.c
index 243eb61..27fa2f0 100644
--- a/drivers/vfio/virqfd.c
+++ b/drivers/vfio/virqfd.c
@@ -17,6 +17,7 @@
#include "pci/vfio_pci_private.h"
static struct workqueue_struct *vfio_irqfd_cleanup_wq;
+static spinlock_t lock;
int __init vfio_pci_virqfd_init(void)
{
@@ -25,6 +26,8 @@ int __init vfio_pci_virqfd_init(void)
if (!vfio_irqfd_cleanup_wq)
return -ENOMEM;
+ spin_lock_init(&lock);
+
return 0;
}
@@ -53,21 +56,21 @@ static int virqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
if (flags & POLLHUP) {
unsigned long flags;
- spin_lock_irqsave(&virqfd->vdev->irqlock, flags);
+ spin_lock_irqsave(&lock, flags);
/*
* The eventfd is closing, if the virqfd has not yet been
* queued for release, as determined by testing whether the
- * vdev pointer to it is still valid, queue it now. As
+ * virqfd pointer to it is still valid, queue it now. As
* with kvm irqfds, we know we won't race against the virqfd
- * going away because we hold wqh->lock to get here.
+ * going away because we hold the lock to get here.
*/
if (*(virqfd->pvirqfd) == virqfd) {
*(virqfd->pvirqfd) = NULL;
virqfd_deactivate(virqfd);
}
- spin_unlock_irqrestore(&virqfd->vdev->irqlock, flags);
+ spin_unlock_irqrestore(&lock, flags);
}
return 0;
@@ -143,16 +146,16 @@ int virqfd_enable(struct vfio_pci_device *vdev,
* we update the pointer to the virqfd under lock to avoid
* pushing multiple jobs to release the same virqfd.
*/
- spin_lock_irq(&vdev->irqlock);
+ spin_lock_irq(&lock);
if (*pvirqfd) {
- spin_unlock_irq(&vdev->irqlock);
+ spin_unlock_irq(&lock);
ret = -EBUSY;
goto err_busy;
}
*pvirqfd = virqfd;
- spin_unlock_irq(&vdev->irqlock);
+ spin_unlock_irq(&lock);
/*
* Install our own custom wake-up handling so we are notified via
@@ -190,19 +193,18 @@ err_fd:
}
EXPORT_SYMBOL_GPL(virqfd_enable);
-void virqfd_disable(struct vfio_pci_device *vdev,
- struct virqfd **pvirqfd)
+void virqfd_disable(struct virqfd **pvirqfd)
{
unsigned long flags;
- spin_lock_irqsave(&vdev->irqlock, flags);
+ spin_lock_irqsave(&lock, flags);
if (*pvirqfd) {
virqfd_deactivate(*pvirqfd);
*pvirqfd = NULL;
}
- spin_unlock_irqrestore(&vdev->irqlock, flags);
+ spin_unlock_irqrestore(&lock, flags);
/*
* Block until we know all outstanding shutdown jobs have completed.
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index a077c48..fb6037b 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -146,7 +146,6 @@ extern int virqfd_enable(struct vfio_pci_device *vdev,
int (*handler)(struct vfio_pci_device *, void *),
void (*thread)(struct vfio_pci_device *, void *),
void *data, struct virqfd **pvirqfd, int fd);
-extern void virqfd_disable(struct vfio_pci_device *vdev,
- struct virqfd **pvirqfd);
+extern void virqfd_disable(struct virqfd **pvirqfd);
#endif /* VFIO_H */
--
2.1.1
On Mon, 2014-10-27 at 19:08 +0100, Antonios Motakis wrote:
> Virqfd just needs to keep accesses to any struct *virqfd safe, but this
> comes into play only when creating or destroying eventfds, so sharing
> the same spinlock with the VFIO bus driver is not necessary.
>
> Signed-off-by: Antonios Motakis <[email protected]>
> ---
> drivers/vfio/pci/vfio_pci_intrs.c | 10 +++++-----
> drivers/vfio/virqfd.c | 24 +++++++++++++-----------
> include/linux/vfio.h | 3 +--
> 3 files changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
> index 3f909bb..e56c814 100644
> --- a/drivers/vfio/pci/vfio_pci_intrs.c
> +++ b/drivers/vfio/pci/vfio_pci_intrs.c
> @@ -226,8 +226,8 @@ static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
> static void vfio_intx_disable(struct vfio_pci_device *vdev)
> {
> vfio_intx_set_signal(vdev, -1);
> - virqfd_disable(vdev, &vdev->ctx[0].unmask);
> - virqfd_disable(vdev, &vdev->ctx[0].mask);
> + virqfd_disable(&vdev->ctx[0].unmask);
> + virqfd_disable(&vdev->ctx[0].mask);
> vdev->irq_type = VFIO_PCI_NUM_IRQS;
> vdev->num_ctx = 0;
> kfree(vdev->ctx);
> @@ -377,8 +377,8 @@ static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
> vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
>
> for (i = 0; i < vdev->num_ctx; i++) {
> - virqfd_disable(vdev, &vdev->ctx[i].unmask);
> - virqfd_disable(vdev, &vdev->ctx[i].mask);
> + virqfd_disable(&vdev->ctx[i].unmask);
> + virqfd_disable(&vdev->ctx[i].mask);
> }
>
> if (msix) {
> @@ -415,7 +415,7 @@ static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev,
> vfio_send_intx_eventfd, NULL,
> &vdev->ctx[0].unmask, fd);
>
> - virqfd_disable(vdev, &vdev->ctx[0].unmask);
> + virqfd_disable(&vdev->ctx[0].unmask);
> }
>
> return 0;
> diff --git a/drivers/vfio/virqfd.c b/drivers/vfio/virqfd.c
> index 243eb61..27fa2f0 100644
> --- a/drivers/vfio/virqfd.c
> +++ b/drivers/vfio/virqfd.c
> @@ -17,6 +17,7 @@
> #include "pci/vfio_pci_private.h"
>
> static struct workqueue_struct *vfio_irqfd_cleanup_wq;
> +static spinlock_t lock;
Define this as:
DEFINE_SPINLOCK(lock);
and we can avoid needing the init.
> int __init vfio_pci_virqfd_init(void)
> {
> @@ -25,6 +26,8 @@ int __init vfio_pci_virqfd_init(void)
> if (!vfio_irqfd_cleanup_wq)
> return -ENOMEM;
>
> + spin_lock_init(&lock);
> +
> return 0;
> }
>
> @@ -53,21 +56,21 @@ static int virqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
>
> if (flags & POLLHUP) {
> unsigned long flags;
> - spin_lock_irqsave(&virqfd->vdev->irqlock, flags);
> + spin_lock_irqsave(&lock, flags);
>
> /*
> * The eventfd is closing, if the virqfd has not yet been
> * queued for release, as determined by testing whether the
> - * vdev pointer to it is still valid, queue it now. As
> + * virqfd pointer to it is still valid, queue it now. As
> * with kvm irqfds, we know we won't race against the virqfd
> - * going away because we hold wqh->lock to get here.
> + * going away because we hold the lock to get here.
> */
> if (*(virqfd->pvirqfd) == virqfd) {
> *(virqfd->pvirqfd) = NULL;
> virqfd_deactivate(virqfd);
> }
>
> - spin_unlock_irqrestore(&virqfd->vdev->irqlock, flags);
> + spin_unlock_irqrestore(&lock, flags);
> }
>
> return 0;
> @@ -143,16 +146,16 @@ int virqfd_enable(struct vfio_pci_device *vdev,
> * we update the pointer to the virqfd under lock to avoid
> * pushing multiple jobs to release the same virqfd.
> */
> - spin_lock_irq(&vdev->irqlock);
> + spin_lock_irq(&lock);
>
> if (*pvirqfd) {
> - spin_unlock_irq(&vdev->irqlock);
> + spin_unlock_irq(&lock);
> ret = -EBUSY;
> goto err_busy;
> }
> *pvirqfd = virqfd;
>
> - spin_unlock_irq(&vdev->irqlock);
> + spin_unlock_irq(&lock);
>
> /*
> * Install our own custom wake-up handling so we are notified via
> @@ -190,19 +193,18 @@ err_fd:
> }
> EXPORT_SYMBOL_GPL(virqfd_enable);
>
> -void virqfd_disable(struct vfio_pci_device *vdev,
> - struct virqfd **pvirqfd)
> +void virqfd_disable(struct virqfd **pvirqfd)
> {
> unsigned long flags;
>
> - spin_lock_irqsave(&vdev->irqlock, flags);
> + spin_lock_irqsave(&lock, flags);
>
> if (*pvirqfd) {
> virqfd_deactivate(*pvirqfd);
> *pvirqfd = NULL;
> }
>
> - spin_unlock_irqrestore(&vdev->irqlock, flags);
> + spin_unlock_irqrestore(&lock, flags);
>
> /*
> * Block until we know all outstanding shutdown jobs have completed.
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index a077c48..fb6037b 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -146,7 +146,6 @@ extern int virqfd_enable(struct vfio_pci_device *vdev,
> int (*handler)(struct vfio_pci_device *, void *),
> void (*thread)(struct vfio_pci_device *, void *),
> void *data, struct virqfd **pvirqfd, int fd);
> -extern void virqfd_disable(struct vfio_pci_device *vdev,
> - struct virqfd **pvirqfd);
> +extern void virqfd_disable(struct virqfd **pvirqfd);
>
> #endif /* VFIO_H */
On Fri, Oct 31, 2014 at 8:43 PM, Alex Williamson
<[email protected]> wrote:
> On Mon, 2014-10-27 at 19:08 +0100, Antonios Motakis wrote:
>> Virqfd just needs to keep accesses to any struct *virqfd safe, but this
>> comes into play only when creating or destroying eventfds, so sharing
>> the same spinlock with the VFIO bus driver is not necessary.
>>
>> Signed-off-by: Antonios Motakis <[email protected]>
>> ---
>> drivers/vfio/pci/vfio_pci_intrs.c | 10 +++++-----
>> drivers/vfio/virqfd.c | 24 +++++++++++++-----------
>> include/linux/vfio.h | 3 +--
>> 3 files changed, 19 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
>> index 3f909bb..e56c814 100644
>> --- a/drivers/vfio/pci/vfio_pci_intrs.c
>> +++ b/drivers/vfio/pci/vfio_pci_intrs.c
>> @@ -226,8 +226,8 @@ static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
>> static void vfio_intx_disable(struct vfio_pci_device *vdev)
>> {
>> vfio_intx_set_signal(vdev, -1);
>> - virqfd_disable(vdev, &vdev->ctx[0].unmask);
>> - virqfd_disable(vdev, &vdev->ctx[0].mask);
>> + virqfd_disable(&vdev->ctx[0].unmask);
>> + virqfd_disable(&vdev->ctx[0].mask);
>> vdev->irq_type = VFIO_PCI_NUM_IRQS;
>> vdev->num_ctx = 0;
>> kfree(vdev->ctx);
>> @@ -377,8 +377,8 @@ static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
>> vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
>>
>> for (i = 0; i < vdev->num_ctx; i++) {
>> - virqfd_disable(vdev, &vdev->ctx[i].unmask);
>> - virqfd_disable(vdev, &vdev->ctx[i].mask);
>> + virqfd_disable(&vdev->ctx[i].unmask);
>> + virqfd_disable(&vdev->ctx[i].mask);
>> }
>>
>> if (msix) {
>> @@ -415,7 +415,7 @@ static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev,
>> vfio_send_intx_eventfd, NULL,
>> &vdev->ctx[0].unmask, fd);
>>
>> - virqfd_disable(vdev, &vdev->ctx[0].unmask);
>> + virqfd_disable(&vdev->ctx[0].unmask);
>> }
>>
>> return 0;
>> diff --git a/drivers/vfio/virqfd.c b/drivers/vfio/virqfd.c
>> index 243eb61..27fa2f0 100644
>> --- a/drivers/vfio/virqfd.c
>> +++ b/drivers/vfio/virqfd.c
>> @@ -17,6 +17,7 @@
>> #include "pci/vfio_pci_private.h"
>>
>> static struct workqueue_struct *vfio_irqfd_cleanup_wq;
>> +static spinlock_t lock;
>
> Define this as:
>
> DEFINE_SPINLOCK(lock);
>
> and we can avoid needing the init.
Ack, thanks.
>
>> int __init vfio_pci_virqfd_init(void)
>> {
>> @@ -25,6 +26,8 @@ int __init vfio_pci_virqfd_init(void)
>> if (!vfio_irqfd_cleanup_wq)
>> return -ENOMEM;
>>
>> + spin_lock_init(&lock);
>> +
>> return 0;
>> }
>>
>> @@ -53,21 +56,21 @@ static int virqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
>>
>> if (flags & POLLHUP) {
>> unsigned long flags;
>> - spin_lock_irqsave(&virqfd->vdev->irqlock, flags);
>> + spin_lock_irqsave(&lock, flags);
>>
>> /*
>> * The eventfd is closing, if the virqfd has not yet been
>> * queued for release, as determined by testing whether the
>> - * vdev pointer to it is still valid, queue it now. As
>> + * virqfd pointer to it is still valid, queue it now. As
>> * with kvm irqfds, we know we won't race against the virqfd
>> - * going away because we hold wqh->lock to get here.
>> + * going away because we hold the lock to get here.
>> */
>> if (*(virqfd->pvirqfd) == virqfd) {
>> *(virqfd->pvirqfd) = NULL;
>> virqfd_deactivate(virqfd);
>> }
>>
>> - spin_unlock_irqrestore(&virqfd->vdev->irqlock, flags);
>> + spin_unlock_irqrestore(&lock, flags);
>> }
>>
>> return 0;
>> @@ -143,16 +146,16 @@ int virqfd_enable(struct vfio_pci_device *vdev,
>> * we update the pointer to the virqfd under lock to avoid
>> * pushing multiple jobs to release the same virqfd.
>> */
>> - spin_lock_irq(&vdev->irqlock);
>> + spin_lock_irq(&lock);
>>
>> if (*pvirqfd) {
>> - spin_unlock_irq(&vdev->irqlock);
>> + spin_unlock_irq(&lock);
>> ret = -EBUSY;
>> goto err_busy;
>> }
>> *pvirqfd = virqfd;
>>
>> - spin_unlock_irq(&vdev->irqlock);
>> + spin_unlock_irq(&lock);
>>
>> /*
>> * Install our own custom wake-up handling so we are notified via
>> @@ -190,19 +193,18 @@ err_fd:
>> }
>> EXPORT_SYMBOL_GPL(virqfd_enable);
>>
>> -void virqfd_disable(struct vfio_pci_device *vdev,
>> - struct virqfd **pvirqfd)
>> +void virqfd_disable(struct virqfd **pvirqfd)
>> {
>> unsigned long flags;
>>
>> - spin_lock_irqsave(&vdev->irqlock, flags);
>> + spin_lock_irqsave(&lock, flags);
>>
>> if (*pvirqfd) {
>> virqfd_deactivate(*pvirqfd);
>> *pvirqfd = NULL;
>> }
>>
>> - spin_unlock_irqrestore(&vdev->irqlock, flags);
>> + spin_unlock_irqrestore(&lock, flags);
>>
>> /*
>> * Block until we know all outstanding shutdown jobs have completed.
>> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
>> index a077c48..fb6037b 100644
>> --- a/include/linux/vfio.h
>> +++ b/include/linux/vfio.h
>> @@ -146,7 +146,6 @@ extern int virqfd_enable(struct vfio_pci_device *vdev,
>> int (*handler)(struct vfio_pci_device *, void *),
>> void (*thread)(struct vfio_pci_device *, void *),
>> void *data, struct virqfd **pvirqfd, int fd);
>> -extern void virqfd_disable(struct vfio_pci_device *vdev,
>> - struct virqfd **pvirqfd);
>> +extern void virqfd_disable(struct virqfd **pvirqfd);
>>
>> #endif /* VFIO_H */
>
>
>