diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-11-18 16:07:01 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2016-11-18 17:29:25 +0200 |
| commit | 0687c37c5eeef8580b31cc6e1202d874833ae38a (patch) | |
| tree | 07374579958bc8d8c91faab6fbf85589a5dc3869 /hw/virtio/virtio-pci.c | |
| parent | 310837de6c1e0badfd736b1b316b1698c53120a7 (diff) | |
| download | qemu-0687c37c5eeef8580b31cc6e1202d874833ae38a.tar.gz | |
virtio: access ISR atomically
This will be needed once dataplane will be able to set it outside
the big QEMU lock.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/virtio/virtio-pci.c')
| -rw-r--r-- | hw/virtio/virtio-pci.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 97b32febaf..521ba0b415 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -73,7 +73,7 @@ static void virtio_pci_notify(DeviceState *d, uint16_t vector) msix_notify(&proxy->pci_dev, vector); else { VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); - pci_set_irq(&proxy->pci_dev, vdev->isr & 1); + pci_set_irq(&proxy->pci_dev, atomic_read(&vdev->isr) & 1); } } @@ -449,8 +449,7 @@ static uint32_t virtio_ioport_read(VirtIOPCIProxy *proxy, uint32_t addr) break; case VIRTIO_PCI_ISR: /* reading from the ISR also clears it. */ - ret = vdev->isr; - vdev->isr = 0; + ret = atomic_xchg(&vdev->isr, 0); pci_irq_deassert(&proxy->pci_dev); break; case VIRTIO_MSI_CONFIG_VECTOR: @@ -1379,9 +1378,7 @@ static uint64_t virtio_pci_isr_read(void *opaque, hwaddr addr, { VirtIOPCIProxy *proxy = opaque; VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); - uint64_t val = vdev->isr; - - vdev->isr = 0; + uint64_t val = atomic_xchg(&vdev->isr, 0); pci_irq_deassert(&proxy->pci_dev); return val; |