diff options
| -rw-r--r-- | hw/virtio.c | 16 | ||||
| -rw-r--r-- | hw/virtio.h | 6 |
2 files changed, 19 insertions, 3 deletions
diff --git a/hw/virtio.c b/hw/virtio.c index 93965800df..4135a97fdc 100644 --- a/hw/virtio.c +++ b/hw/virtio.c @@ -52,6 +52,14 @@ /* Virtio ABI version, if we increment this, we break the guest driver. */ #define VIRTIO_PCI_ABI_VERSION 0 +/* How many bits to shift physical queue address written to QUEUE_PFN. + * 12 is historical, and due to x86 page size. */ +#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 + +/* The alignment to use between consumer and producer parts of vring. + * x86 pagesize again. */ +#define VIRTIO_PCI_VRING_ALIGN 4096 + /* QEMU doesn't strictly need write barriers since everything runs in * lock-step. We'll leave the calls to wmb() in though to make it obvious for * KVM or if kqemu gets SMP support. @@ -147,7 +155,9 @@ static void virtqueue_init(VirtQueue *vq, target_phys_addr_t pa) { vq->vring.desc = pa; vq->vring.avail = pa + vq->vring.num * sizeof(VRingDesc); - vq->vring.used = TARGET_PAGE_ALIGN(vq->vring.avail + offsetof(VRingAvail, ring[vq->vring.num])); + vq->vring.used = vring_align(vq->vring.avail + + offsetof(VRingAvail, ring[vq->vring.num]), + VIRTIO_PCI_VRING_ALIGN); } static inline uint64_t vring_desc_addr(VirtQueue *vq, int i) @@ -501,7 +511,7 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) vdev->features = val; break; case VIRTIO_PCI_QUEUE_PFN: - pa = (ram_addr_t)val << TARGET_PAGE_BITS; + pa = (ram_addr_t)val << VIRTIO_PCI_QUEUE_ADDR_SHIFT; vdev->vq[vdev->queue_sel].pfn = val; if (pa == 0) { virtio_reset(vdev); @@ -776,7 +786,7 @@ void virtio_load(VirtIODevice *vdev, QEMUFile *f) if (vdev->vq[i].pfn) { target_phys_addr_t pa; - pa = (ram_addr_t)vdev->vq[i].pfn << TARGET_PAGE_BITS; + pa = (ram_addr_t)vdev->vq[i].pfn << VIRTIO_PCI_QUEUE_ADDR_SHIFT; virtqueue_init(&vdev->vq[i], pa); } } diff --git a/hw/virtio.h b/hw/virtio.h index f04e75f887..8c9cbaf63e 100644 --- a/hw/virtio.h +++ b/hw/virtio.h @@ -48,6 +48,12 @@ struct VirtQueue; +static inline target_phys_addr_t vring_align(target_phys_addr_t addr, + unsigned long align) +{ + return (addr + align - 1) & ~(align - 1); +} + typedef struct VirtQueue VirtQueue; typedef struct VirtIODevice VirtIODevice; |