[OE-core] [PATCH] qemux86: Support for KVM, paravirt and virtio added

[Iorga, Cristian]

Hello Saul,

Thanks.

Good question. :-)
I think it's a definitely yes.
Although I need to check :-)
However, in the case of x86-64, there will be a small limitation.
The guest OS can be used only on a x86-64 machine (and I am guessing, also with a 64 bits enabled OS).

Regards,
Cristian


-----Original Message-----
From: Saul Wold [mailto:sgw at linux.intel.com] 
Sent: Tuesday, September 18, 2012 3:24 AM
To: Iorga, Cristian
Cc: 'Patches and discussions about the oe-core layer'
Subject: Re: [OE-core] [PATCH] qemux86: Support for KVM, paravirt and virtio added

On 09/17/2012 04:53 AM, Cristian Iorga wrote:
> KVM, paravirtualization and virtio drivers are now activated in 
> runqemu using the kvm option flag for qemux86.
> Host CPU features are also exported to guest OS (Yocto Linux).
> Usage example: runqemu qemux86 core-image-x11 kvm
>
> Implements [YOCTO #2550].
>
> Signed-off-by: Cristian Iorga <cristian.iorga at intel.com>
> ---
>   meta/recipes-kernel/linux/linux-yocto_3.4.bb |    1 +
>   scripts/runqemu                              |   16 +++++++++++++++-
>   scripts/runqemu-internal                     |   14 +++++++++++---
>   3 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/meta/recipes-kernel/linux/linux-yocto_3.4.bb 
> b/meta/recipes-kernel/linux/linux-yocto_3.4.bb
> index 7c082e7..32ae02b 100644
> --- a/meta/recipes-kernel/linux/linux-yocto_3.4.bb
> +++ b/meta/recipes-kernel/linux/linux-yocto_3.4.bb
> @@ -27,4 +27,5 @@ KERNEL_REVISION_CHECKING=""
>   KERNEL_FEATURES_append = " features/netfilter"
>   KERNEL_FEATURES_append_qemux86=" cfg/sound"
>   KERNEL_FEATURES_append_qemux86-64=" cfg/sound"
> +KERNEL_FEATURES_append_qemux86=" cfg/paravirt_kvm"

Good patch, with one question.

Can the be a valid KERNEL_FEATURE for x86-64 also? Any reason not to?

Sau!


>   KERNEL_FEATURES_append = " ${@bb.utils.contains("TUNE_FEATURES", "mx32", " cfg/x32", "" ,d)}"
> diff --git a/scripts/runqemu b/scripts/runqemu index e843946..167e157 
> 100755
> --- a/scripts/runqemu
> +++ b/scripts/runqemu
> @@ -208,6 +208,7 @@ if [ -z "$MACHINE" ]; then
>   fi
>
>   YOCTO_KVM_WIKI="https://wiki.yoctoproject.org/wiki/How_to_enable_KVM_for_Poky_qemu"
> +YOCTO_PARAVIRT_KVM_WIKI="https://wiki.yoctoproject.org/wiki/Running_an_x86_Yocto_Linux_image_under_QEMU_KVM"
>   # Detect KVM configuration
>   if [ "x$KVM_ENABLED" = "xyes" ]; then
>       if [ -z "$KVM_CAPABLE" ]; then
> @@ -226,14 +227,27 @@ if [ "x$KVM_ENABLED" = "xyes" ]; then
>           echo "$YOCTO_KVM_WIKI";
>           exit 1;
>       fi
> +    if [ ! -e /dev/vhost-net ]; then
> +        echo "Missing virtio net device. Have you inserted vhost-net module?"
> +        echo "For further help see"
> +        echo "$YOCTO_PARAVIRT_KVM_WIKI";
> +        exit 1;
> +    fi
>       if 9<>/dev/kvm ; then
> -        SCRIPT_QEMU_OPT="$SCRIPT_QEMU_OPT -enable-kvm"
> +        SCRIPT_QEMU_OPT="$SCRIPT_QEMU_OPT -enable-kvm -cpu host"
> +        KVM_ACTIVE="yes"
>       else
>           echo "You have no rights on /dev/kvm."
>           echo "Please change the ownership of this file as described at"
>           echo "$YOCTO_KVM_WIKI";
>           exit 1;
>       fi
> +    if [ ! -w /dev/vhost-net -a -r /dev/vhost-net ]; then
> +        echo "You have no rights on /dev/vhost-net."
> +        echo "Please change the ownership of this file as described at"
> +        echo "$YOCTO_PARAVIRT_KVM_WIKI";
> +        exit 1;
> +    fi
>   fi
>
>   machine2=`echo $MACHINE | tr 'a-z' 'A-Z' | sed 's/-/_/'` diff --git 
> a/scripts/runqemu-internal b/scripts/runqemu-internal index 
> a9b1c44..f2c8d83 100755
> --- a/scripts/runqemu-internal
> +++ b/scripts/runqemu-internal
> @@ -221,7 +221,15 @@ n2=$(($n1 + 1))
>
>   KERNEL_NETWORK_CMD="ip=192.168.7.$n2::192.168.7.$n1:255.255.255.0"
>   QEMU_TAP_CMD="-net tap,vlan=0,ifname=$TAP,script=no,downscript=no"
> -QEMU_NETWORK_CMD="-net nic,vlan=0 $QEMU_TAP_CMD"
> +if [ "$KVM_ACTIVE" = "yes" ]; then
> +    QEMU_NETWORK_CMD="-net nic,model=virtio $QEMU_TAP_CMD,vhost=on"
> +    DROOT="/dev/vda"
> +    ROOTFS_OPTIONS="-drive file=$ROOTFS,if=virtio"
> +else
> +    QEMU_NETWORK_CMD="-net nic,vlan=0 $QEMU_TAP_CMD"
> +    DROOT="/dev/hda"
> +    ROOTFS_OPTIONS="-hda $ROOTFS"
> +fi
>   KERNCMDLINE="mem=$QEMU_MEMORY"
>   QEMU_UI_OPTIONS="-show-cursor -usb -usbdevice wacom-tablet"
>
> @@ -321,8 +329,8 @@ if [ "$MACHINE" = "qemux86" ]; then
>       QEMU=qemu-system-i386
>       QEMU_UI_OPTIONS="$QEMU_UI_OPTIONS -vga vmware"
>       if [ "$FSTYPE" = "ext2" -o "$FSTYPE" = "ext3" -o "$FSTYPE" = "btrfs" ]; then
> -        KERNCMDLINE="vga=0 root=/dev/hda rw mem=$QEMU_MEMORY $KERNEL_NETWORK_CMD"
> -        QEMUOPTIONS="$QEMU_NETWORK_CMD -hda $ROOTFS $QEMU_UI_OPTIONS"
> +        KERNCMDLINE="vga=0 root=$DROOT rw mem=$QEMU_MEMORY $KERNEL_NETWORK_CMD"
> +        QEMUOPTIONS="$QEMU_NETWORK_CMD $ROOTFS_OPTIONS $QEMU_UI_OPTIONS"
>       fi
>       if [ "$FSTYPE" = "nfs" ]; then
>           if [ "$NFS_SERVER" = "192.168.7.1" -a ! -d "$NFS_DIR" ]; 
> then
>