Virtualization - Jul 2012 - [PATCH] hw/virtio-scsi: Set max_target=0 during vhost-scsi operation

From: Nicholas Bellinger <nab at linux-iscsi.org>

This QEMU patch sets VirtIOSCSIConfig->max_target=0 for vhost-scsi operation
to restrict virtio-scsi LLD guest scanning to max_id=0 (a single target ID
instance) when connected to individual tcm_vhost endpoints as requested by
Paolo.

This ensures that virtio-scsi LLD only attempts to scan target IDs up to
VIRTIO_SCSI_MAX_TARGET when connected via virtio-scsi-raw.

It's currently cut against Zhi's qemu vhost-scsi tree here:

   https://github.com/wuzhy/qemu/tree/vhost-scsi

Cc: Stefan Hajnoczi <stefanha at linux.vnet.ibm.com>
Cc: Zhi Yong Wu <wuzhy at linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
---
 hw/virtio-scsi.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c
index e38cdd0..71276b6 100644
--- a/hw/virtio-scsi.c
+++ b/hw/virtio-scsi.c
@@ -523,7 +523,11 @@ static void virtio_scsi_get_config(VirtIODevice *vdev,
     stl_raw(&scsiconf->sense_size, s->sense_size);
     stl_raw(&scsiconf->cdb_size, s->cdb_size);
     stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
-    stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
+    if (s->vhost_scsi) {
+        stl_raw(&scsiconf->max_target, 0);
+    } else {
+        stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
+    }
     stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 }
 
-- 
1.7.2.5

HI,

Do we need to maintain one QEMU branch to collect all useful latest
patches for tcm_vhost support?  You know, those patches will not get
merged into qemu.git/master.


On Thu, Jul 12, 2012 at 4:55 AM, Nicholas A. Bellinger
<nab at linux-iscsi.org> wrote:
> From: Nicholas Bellinger <nab at linux-iscsi.org>
>
> This QEMU patch sets VirtIOSCSIConfig->max_target=0 for vhost-scsi
operation
> to restrict virtio-scsi LLD guest scanning to max_id=0 (a single target ID
> instance) when connected to individual tcm_vhost endpoints as requested by
> Paolo.
>
> This ensures that virtio-scsi LLD only attempts to scan target IDs up to
> VIRTIO_SCSI_MAX_TARGET when connected via virtio-scsi-raw.
>
> It's currently cut against Zhi's qemu vhost-scsi tree here:
>
>    https://github.com/wuzhy/qemu/tree/vhost-scsi
>
> Cc: Stefan Hajnoczi <stefanha at linux.vnet.ibm.com>
> Cc: Zhi Yong Wu <wuzhy at linux.vnet.ibm.com>
> Cc: Paolo Bonzini <pbonzini at redhat.com>
> Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
> ---
>  hw/virtio-scsi.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c
> index e38cdd0..71276b6 100644
> --- a/hw/virtio-scsi.c
> +++ b/hw/virtio-scsi.c
> @@ -523,7 +523,11 @@ static void virtio_scsi_get_config(VirtIODevice *vdev,
>      stl_raw(&scsiconf->sense_size, s->sense_size);
>      stl_raw(&scsiconf->cdb_size, s->cdb_size);
>      stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
> -    stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
> +    if (s->vhost_scsi) {
> +        stl_raw(&scsiconf->max_target, 0);
> +    } else {
> +        stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
> +    }
>      stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
>  }
>
> --
> 1.7.2.5
>
> --
> You received this message because you are subscribed to the Google Groups
"Linux-iSCSI.org Target Development" group.
> To post to this group, send email to linux-iscsi-target-dev at
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>


-- 
Regards,

Zhi Yong Wu

Il 12/07/2012 07:34, Zhi Yong Wu ha scritto:
> HI,
> 
> Do we need to maintain one QEMU branch to collect all useful latest
> patches for tcm_vhost support?  You know, those patches will not get
> merged into qemu.git/master.
Never say never, but the answer to your question is yes: please apply
this patch to your vhost-scsi branch and push it to github.

Paolo

thanks, it is applied to my vhost_scsi git tree
git://github.com/mdroth/qemu.git vhost-scsi


On Thu, Jul 12, 2012 at 4:55 AM, Nicholas A. Bellinger
<nab at linux-iscsi.org> wrote:
> From: Nicholas Bellinger <nab at linux-iscsi.org>
>
> This QEMU patch sets VirtIOSCSIConfig->max_target=0 for vhost-scsi
operation
> to restrict virtio-scsi LLD guest scanning to max_id=0 (a single target ID
> instance) when connected to individual tcm_vhost endpoints as requested by
> Paolo.
>
> This ensures that virtio-scsi LLD only attempts to scan target IDs up to
> VIRTIO_SCSI_MAX_TARGET when connected via virtio-scsi-raw.
>
> It's currently cut against Zhi's qemu vhost-scsi tree here:
>
>    https://github.com/wuzhy/qemu/tree/vhost-scsi
>
> Cc: Stefan Hajnoczi <stefanha at linux.vnet.ibm.com>
> Cc: Zhi Yong Wu <wuzhy at linux.vnet.ibm.com>
> Cc: Paolo Bonzini <pbonzini at redhat.com>
> Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
> ---
>  hw/virtio-scsi.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c
> index e38cdd0..71276b6 100644
> --- a/hw/virtio-scsi.c
> +++ b/hw/virtio-scsi.c
> @@ -523,7 +523,11 @@ static void virtio_scsi_get_config(VirtIODevice *vdev,
>      stl_raw(&scsiconf->sense_size, s->sense_size);
>      stl_raw(&scsiconf->cdb_size, s->cdb_size);
>      stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
> -    stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
> +    if (s->vhost_scsi) {
> +        stl_raw(&scsiconf->max_target, 0);
> +    } else {
> +        stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
> +    }
>      stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
>  }
>
> --
> 1.7.2.5
>
> --
> You received this message because you are subscribed to the Google Groups
"Linux-iSCSI.org Target Development" group.
> To post to this group, send email to linux-iscsi-target-dev at
googlegroups.com.
> To unsubscribe from this group, send email to
linux-iscsi-target-dev+unsubscribe at googlegroups.com.
> For more options, visit this group at
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>


-- 
Regards,

Zhi Yong Wu

thanks, it is applied to my vhost_scsi git tree
git://github.com/wuzhy/qemu.git vhost-scsi

On Thu, Jul 12, 2012 at 4:55 AM, Nicholas A. Bellinger
<nab at linux-iscsi.org> wrote:
> From: Nicholas Bellinger <nab at linux-iscsi.org>
>
> This QEMU patch sets VirtIOSCSIConfig->max_target=0 for vhost-scsi
operation
> to restrict virtio-scsi LLD guest scanning to max_id=0 (a single target ID
> instance) when connected to individual tcm_vhost endpoints as requested by
> Paolo.
>
> This ensures that virtio-scsi LLD only attempts to scan target IDs up to
> VIRTIO_SCSI_MAX_TARGET when connected via virtio-scsi-raw.
>
> It's currently cut against Zhi's qemu vhost-scsi tree here:
>
>    https://github.com/wuzhy/qemu/tree/vhost-scsi
>
> Cc: Stefan Hajnoczi <stefanha at linux.vnet.ibm.com>
> Cc: Zhi Yong Wu <wuzhy at linux.vnet.ibm.com>
> Cc: Paolo Bonzini <pbonzini at redhat.com>
> Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
> ---
>  hw/virtio-scsi.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c
> index e38cdd0..71276b6 100644
> --- a/hw/virtio-scsi.c
> +++ b/hw/virtio-scsi.c
> @@ -523,7 +523,11 @@ static void virtio_scsi_get_config(VirtIODevice *vdev,
>      stl_raw(&scsiconf->sense_size, s->sense_size);
>      stl_raw(&scsiconf->cdb_size, s->cdb_size);
>      stl_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
> -    stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
> +    if (s->vhost_scsi) {
> +        stl_raw(&scsiconf->max_target, 0);
> +    } else {
> +        stl_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
> +    }
>      stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
>  }
>
> --
> 1.7.2.5
>
> --
> You received this message because you are subscribed to the Google Groups
"Linux-iSCSI.org Target Development" group.
> To post to this group, send email to linux-iscsi-target-dev at
googlegroups.com.
> To unsubscribe from this group, send email to
linux-iscsi-target-dev+unsubscribe at googlegroups.com.
> For more options, visit this group at
http://groups.google.com/group/linux-iscsi-target-dev?hl=en.
>


-- 
Regards,

Zhi Yong Wu