Commit a9718ef0 authored by Pierre Morel's avatar Pierre Morel Committed by Stefan Hajnoczi
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virtio dataplane: adapt dataplane for virtio Version 1 



Let dataplane allocate different region for the desc/avail/used
ring regions.
Take VIRTIO_RING_F_EVENT_IDX into account to increase the used/avail
rings accordingly.

[Fix 32-bit builds by changing 16lx format specifier to HWADDR_PRIx.
--Stefan]

Signed-off-by: default avatarPierre Morel <pmorel@linux.vnet.ibm.com>
Tested-by: default avatarGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: default avatarGreg Kurz <gkurz@linux.vnet.ibm.com>
Message-id: 1441625636-23773-1-git-send-email-pmorel@linux.vnet.ibm.com
(changed __virtio16 into uint16_t,
 map descriptor table and available ring read-only)
Signed-off-by: default avatarGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent fc73548e

hw/virtio/dataplane/vring.c

+55 −14
Original line number Diff line number Diff line
@@ -67,22 +67,53 @@ static void vring_unmap(void *buffer, bool is_write) 
/* Map the guest's vring to host memory */

bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)

{

    hwaddr vring_addr = virtio_queue_get_ring_addr(vdev, n);

    hwaddr vring_size = virtio_queue_get_ring_size(vdev, n);

    void *vring_ptr;

    struct vring *vr = &vring->vr;

    hwaddr addr;

    hwaddr size;

    void *ptr;



    vring->broken = false;



    vring_ptr = vring_map(&vring->mr, vring_addr, vring_size, true);

    if (!vring_ptr) {

        error_report("Failed to map vring "

                     "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,

                     vring_addr, vring_size);

        vring->broken = true;

        return false;

    }



    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);

    vr->num = virtio_queue_get_num(vdev, n);



    addr = virtio_queue_get_desc_addr(vdev, n);

    size = virtio_queue_get_desc_size(vdev, n);

    /* Map the descriptor area as read only */

    ptr = vring_map(&vring->mr_desc, addr, size, false);

    if (!ptr) {

        error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring desc "

                     "at 0x%" HWADDR_PRIx,

                      size, addr);

        goto out_err_desc;

    }

    vr->desc = ptr;



    addr = virtio_queue_get_avail_addr(vdev, n);

    size = virtio_queue_get_avail_size(vdev, n);

    /* Add the size of the used_event_idx */

    size += sizeof(uint16_t);

    /* Map the driver area as read only */

    ptr = vring_map(&vring->mr_avail, addr, size, false);

    if (!ptr) {

        error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring avail "

                     "at 0x%" HWADDR_PRIx,

                      size, addr);

        goto out_err_avail;

    }

    vr->avail = ptr;



    addr = virtio_queue_get_used_addr(vdev, n);

    size = virtio_queue_get_used_size(vdev, n);

    /* Add the size of the avail_event_idx */

    size += sizeof(uint16_t);

    /* Map the device area as read-write */

    ptr = vring_map(&vring->mr_used, addr, size, true);

    if (!ptr) {

        error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring used "

                     "at 0x%" HWADDR_PRIx,

                      size, addr);

        goto out_err_used;

    }

    vr->used = ptr;



    vring->last_avail_idx = virtio_queue_get_last_avail_idx(vdev, n);

    vring->last_used_idx = vring_get_used_idx(vdev, vring);
@@ -92,6 +123,14 @@ bool vring_setup(Vring *vring, VirtIODevice *vdev, int n) 
    trace_vring_setup(virtio_queue_get_ring_addr(vdev, n),

                      vring->vr.desc, vring->vr.avail, vring->vr.used);

    return true;



out_err_used:

    memory_region_unref(vring->mr_avail);

out_err_avail:

    memory_region_unref(vring->mr_desc);

out_err_desc:

    vring->broken = true;

    return false;

}



void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
@@ -99,7 +138,9 @@ void vring_teardown(Vring *vring, VirtIODevice *vdev, int n) 
    virtio_queue_set_last_avail_idx(vdev, n, vring->last_avail_idx);

    virtio_queue_invalidate_signalled_used(vdev, n);



    memory_region_unref(vring->mr);

    memory_region_unref(vring->mr_desc);

    memory_region_unref(vring->mr_avail);

    memory_region_unref(vring->mr_used);

}



/* Disable guest->host notifies */

include/hw/virtio/dataplane/vring.h

+3 −1
Original line number Diff line number Diff line
@@ -22,7 +22,9 @@ 
#include "hw/virtio/virtio.h"



typedef struct {

    MemoryRegion *mr;               /* memory region containing the vring */

    MemoryRegion *mr_desc;          /* memory region for the vring desc */

    MemoryRegion *mr_avail;         /* memory region for the vring avail */

    MemoryRegion *mr_used;          /* memory region for the vring used */

    struct vring vr;                /* virtqueue vring mapped to host memory */

    uint16_t last_avail_idx;        /* last processed avail ring index */

    uint16_t last_used_idx;         /* last processed used ring index */