On Wed, Jul 07, 2010 at 01:34:22PM +0100, Stefan Hajnoczi wrote:
The VRING_AVAIL_F_NO_INTERRUPT flag is a hint that interrupts should be suppressed. It does not guarantee that interrupts will not be raised. Therefore, make sure to clear the interrupt after each virtio-blk read. This avoids a stuck interrupt interfering with the OS loaded later in the boot process.
Signed-off-by: Stefan Hajnoczi stefanha@linux.vnet.ibm.com
Acked-by: Gleb Natapov gleb@redhat.com
src/virtio-blk.c | 6 ++++++ src/virtio-pci.h | 4 ++++ 2 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/src/virtio-blk.c b/src/virtio-blk.c index 16d9ad8..74af488 100644 --- a/src/virtio-blk.c +++ b/src/virtio-blk.c @@ -62,6 +62,12 @@ virtio_blk_read(struct disk_op_s *op)
/* Reclaim virtqueue element */ vring_get_buf(vq, NULL);
- /* Clear interrupt status register. Avoid leaving interrupts stuck if
* VRING_AVAIL_F_NO_INTERRUPT was ignored and interrupts were raised.*/- vp_get_isr(GET_GLOBAL(vdrive_g->ioaddr));
- return status == VIRTIO_BLK_S_OK ? DISK_RET_SUCCESS : DISK_RET_EBADTRACK;
}
diff --git a/src/virtio-pci.h b/src/virtio-pci.h index 9da761d..d21d5a5 100644 --- a/src/virtio-pci.h +++ b/src/virtio-pci.h @@ -71,6 +71,10 @@ static inline void vp_set_status(unsigned int ioaddr, u8 status) outb(status, ioaddr + VIRTIO_PCI_STATUS); }
+static inline u8 vp_get_isr(unsigned int ioaddr) +{
- return inb(ioaddr + VIRTIO_PCI_ISR);
+}
static inline void vp_reset(unsigned int ioaddr) { -- 1.7.1
-- Gleb.