diff mbox

[v5] virtio dataplane: adapt dataplane for virtio Version 1

Message ID 1441625636-23773-1-git-send-email-pmorel@linux.vnet.ibm.com
State New
Headers show

Commit Message

Pierre Morel Sept. 7, 2015, 11:33 a.m. UTC 
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.

Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
(changed __virtio16 into uint16_t,
 map descriptor table and available ring read-only)
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
---

Changes from V4:
- added comments for VIRTIO_RING_F_EVENT_IDX and mapping
- use uint16_t as in ring definitions instead of __virtio16
- map descriptor table and available ring read-only

Changes from V3:
- added changelog

Changes from V2:
- incorporate the code directly in vring_setup().
- added room for the event indexes used with VIRTIO_RING_F_EVENT_IDX

Changes from v1:
- use a macro to gain LOCs inside of vring_setup()

 hw/virtio/dataplane/vring.c         | 66 +++++++++++++++++++++++++++++--------
 include/hw/virtio/dataplane/vring.h |  4 ++-
 2 files changed, 55 insertions(+), 15 deletions(-)

Comments

Greg Kurz Sept. 7, 2015, 3:03 p.m. UTC | #1 
On Mon,  7 Sep 2015 13:33:56 +0200
Pierre Morel <pmorel@linux.vnet.ibm.com> wrote:
> 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.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
> (changed __virtio16 into uint16_t,
>  map descriptor table and available ring read-only)
> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
> ---
> 

I have tested it works on ppc64.

Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>

> Changes from V4:
> - added comments for VIRTIO_RING_F_EVENT_IDX and mapping
> - use uint16_t as in ring definitions instead of __virtio16
> - map descriptor table and available ring read-only
> 
> Changes from V3:
> - added changelog
> 
> Changes from V2:
> - incorporate the code directly in vring_setup().
> - added room for the event indexes used with VIRTIO_RING_F_EVENT_IDX
> 
> Changes from v1:
> - use a macro to gain LOCs inside of vring_setup()
> 
>  hw/virtio/dataplane/vring.c         | 66 +++++++++++++++++++++++++++++--------
>  include/hw/virtio/dataplane/vring.h |  4 ++-
>  2 files changed, 55 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
> index 07fd69c..75db534 100644
> --- a/hw/virtio/dataplane/vring.c
> +++ b/hw/virtio/dataplane/vring.c
> @@ -67,22 +67,50 @@ 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;
> +    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%16lx byte for vring desc at %16lx",
> +                      size, addr);
> +        goto out_err_desc;
>      }
> -
> -    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
> +    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%16lx byte for vring avail at %16lx",
> +                      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%16lx byte for vring used at %16lx",
> +                      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 +120,14 @@ 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 +135,9 @@ 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 */
> diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h
> index 8d97db9..a596e4c 100644
> --- a/include/hw/virtio/dataplane/vring.h
> +++ b/include/hw/virtio/dataplane/vring.h
> @@ -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 */
Greg Kurz Sept. 8, 2015, 7:43 a.m. UTC | #2 
On Mon,  7 Sep 2015 13:33:56 +0200
Pierre Morel <pmorel@linux.vnet.ibm.com> wrote:

> 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.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
> (changed __virtio16 into uint16_t,
>  map descriptor table and available ring read-only)
> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
> ---
> 

As suggested by Michael during the review of v2.

Cc: qemu-stable@nongnu.org

--
Greg

> Changes from V4:
> - added comments for VIRTIO_RING_F_EVENT_IDX and mapping
> - use uint16_t as in ring definitions instead of __virtio16
> - map descriptor table and available ring read-only
> 
> Changes from V3:
> - added changelog
> 
> Changes from V2:
> - incorporate the code directly in vring_setup().
> - added room for the event indexes used with VIRTIO_RING_F_EVENT_IDX
> 
> Changes from v1:
> - use a macro to gain LOCs inside of vring_setup()
> 
>  hw/virtio/dataplane/vring.c         | 66 +++++++++++++++++++++++++++++--------
>  include/hw/virtio/dataplane/vring.h |  4 ++-
>  2 files changed, 55 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
> index 07fd69c..75db534 100644
> --- a/hw/virtio/dataplane/vring.c
> +++ b/hw/virtio/dataplane/vring.c
> @@ -67,22 +67,50 @@ 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;
> +    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%16lx byte for vring desc at %16lx",
> +                      size, addr);
> +        goto out_err_desc;
>      }
> -
> -    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
> +    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%16lx byte for vring avail at %16lx",
> +                      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%16lx byte for vring used at %16lx",
> +                      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 +120,14 @@ 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 +135,9 @@ 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 */
> diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h
> index 8d97db9..a596e4c 100644
> --- a/include/hw/virtio/dataplane/vring.h
> +++ b/include/hw/virtio/dataplane/vring.h
> @@ -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 */
Stefan Hajnoczi Sept. 9, 2015, 9:29 a.m. UTC | #3 
On Mon, Sep 07, 2015 at 01:33:56PM +0200, Pierre Morel wrote:
> 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.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
> (changed __virtio16 into uint16_t,
>  map descriptor table and available ring read-only)
> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
> ---
> 
> Changes from V4:
> - added comments for VIRTIO_RING_F_EVENT_IDX and mapping
> - use uint16_t as in ring definitions instead of __virtio16
> - map descriptor table and available ring read-only
> 
> Changes from V3:
> - added changelog
> 
> Changes from V2:
> - incorporate the code directly in vring_setup().
> - added room for the event indexes used with VIRTIO_RING_F_EVENT_IDX
> 
> Changes from v1:
> - use a macro to gain LOCs inside of vring_setup()
> 
>  hw/virtio/dataplane/vring.c         | 66 +++++++++++++++++++++++++++++--------
>  include/hw/virtio/dataplane/vring.h |  4 ++-
>  2 files changed, 55 insertions(+), 15 deletions(-)

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan
Michael S. Tsirkin Sept. 9, 2015, 12:02 p.m. UTC | #4 
On Mon, Sep 07, 2015 at 01:33:56PM +0200, Pierre Morel wrote:
> 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.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
> (changed __virtio16 into uint16_t,
>  map descriptor table and available ring read-only)
> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>


> ---
> 
> Changes from V4:
> - added comments for VIRTIO_RING_F_EVENT_IDX and mapping
> - use uint16_t as in ring definitions instead of __virtio16
> - map descriptor table and available ring read-only
> 
> Changes from V3:
> - added changelog
> 
> Changes from V2:
> - incorporate the code directly in vring_setup().
> - added room for the event indexes used with VIRTIO_RING_F_EVENT_IDX
> 
> Changes from v1:
> - use a macro to gain LOCs inside of vring_setup()
> 
>  hw/virtio/dataplane/vring.c         | 66 +++++++++++++++++++++++++++++--------
>  include/hw/virtio/dataplane/vring.h |  4 ++-
>  2 files changed, 55 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
> index 07fd69c..75db534 100644
> --- a/hw/virtio/dataplane/vring.c
> +++ b/hw/virtio/dataplane/vring.c
> @@ -67,22 +67,50 @@ 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;
> +    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%16lx byte for vring desc at %16lx",
> +                      size, addr);
> +        goto out_err_desc;
>      }
> -
> -    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
> +    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%16lx byte for vring avail at %16lx",
> +                      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%16lx byte for vring used at %16lx",
> +                      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 +120,14 @@ 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 +135,9 @@ 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 */
> diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h
> index 8d97db9..a596e4c 100644
> --- a/include/hw/virtio/dataplane/vring.h
> +++ b/include/hw/virtio/dataplane/vring.h
> @@ -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 */
> -- 
> 2.3.0
Greg Kurz Sept. 9, 2015, 12:46 p.m. UTC | #5 
On Wed, 9 Sep 2015 10:29:51 +0100
Stefan Hajnoczi <stefanha@gmail.com> wrote:

> On Mon, Sep 07, 2015 at 01:33:56PM +0200, Pierre Morel wrote:
> > 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.
> > 
> > Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
> > (changed __virtio16 into uint16_t,
> >  map descriptor table and available ring read-only)
> > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
> > ---
> > 
> > Changes from V4:
> > - added comments for VIRTIO_RING_F_EVENT_IDX and mapping
> > - use uint16_t as in ring definitions instead of __virtio16
> > - map descriptor table and available ring read-only
> > 
> > Changes from V3:
> > - added changelog
> > 
> > Changes from V2:
> > - incorporate the code directly in vring_setup().
> > - added room for the event indexes used with VIRTIO_RING_F_EVENT_IDX
> > 
> > Changes from v1:
> > - use a macro to gain LOCs inside of vring_setup()
> > 
> >  hw/virtio/dataplane/vring.c         | 66 +++++++++++++++++++++++++++++--------
> >  include/hw/virtio/dataplane/vring.h |  4 ++-
> >  2 files changed, 55 insertions(+), 15 deletions(-)
> 
> Thanks, applied to my block tree:
> https://github.com/stefanha/qemu/commits/block
> 
> Stefan
> 

Cc: qemu-stable@nongnu.org

--
Greg
diff mbox

Patch

diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
index 07fd69c..75db534 100644
--- a/hw/virtio/dataplane/vring.c
+++ b/hw/virtio/dataplane/vring.c
@@ -67,22 +67,50 @@  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;
+    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%16lx byte for vring desc at %16lx",
+                      size, addr);
+        goto out_err_desc;
     }
-
-    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
+    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%16lx byte for vring avail at %16lx",
+                      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%16lx byte for vring used at %16lx",
+                      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 +120,14 @@  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 +135,9 @@  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 */
diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h
index 8d97db9..a596e4c 100644
--- a/include/hw/virtio/dataplane/vring.h
+++ b/include/hw/virtio/dataplane/vring.h
@@ -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 */