mbox

[1/2] Qemu: add a group kvm to access /dev/kvm eaiser

Message ID 1465551408-1022-1-git-send-email-jonatan.schlag@ipfire.org
State Superseded
Headers

Message

Jonatan Schlag June 10, 2016, 7:36 p.m. UTC 
  As a normal user, it is not possible to use qemu with KVM. This is bad
because it is better when it is possible to start the machine with a
less privileged user. To achieve this a group KVM is created and the
access to /dev/kvm is allowed for this group. So every user in this
group can use qemu with KVM.
This change is also useful for libvirt because the VMs can be started
with user nobody and group kvm.

Signed-off-by: Jonatan Schlag <jonatan.schlag@ipfire.org>
---
 config/qemu/65-kvm.rules       | 2 ++
 config/rootfiles/packages/qemu | 1 +
 lfs/qemu                       | 4 +++-
 src/paks/qemu/install.sh       | 2 ++
 4 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 config/qemu/65-kvm.rules

Comments

Michael Tremer June 16, 2016, 6:31 p.m. UTC | #1 
On Fri, 2016-06-10 at 11:36 +0200, Jonatan Schlag wrote:
> As a normal user, it is not possible to use qemu with KVM. This is bad
> because it is better when it is possible to start the machine with a
> less privileged user. To achieve this a group KVM is created and the
> access to /dev/kvm is allowed for this group. So every user in this
> group can use qemu with KVM.
> This change is also useful for libvirt because the VMs can be started
> with user nobody and group kvm.
> 
> Signed-off-by: Jonatan Schlag <jonatan.schlag@ipfire.org>
> ---
>  config/qemu/65-kvm.rules       | 2 ++
>  config/rootfiles/packages/qemu | 1 +
>  lfs/qemu                       | 4 +++-
>  src/paks/qemu/install.sh       | 2 ++
>  4 files changed, 8 insertions(+), 1 deletion(-)
>  create mode 100644 config/qemu/65-kvm.rules
> 
> diff --git a/config/qemu/65-kvm.rules b/config/qemu/65-kvm.rules
> new file mode 100644
> index 0000000..569ded9
> --- /dev/null
> +++ b/config/qemu/65-kvm.rules
> @@ -0,0 +1,2 @@
> +KERNEL=="kvm", GROUP="kvm", MODE="0660"
> +KERNEL=="vhost-net", GROUP="kvm", MODE="0660", TAG+="uaccess",
> OPTIONS+="static_node=vhost-net"
> diff --git a/config/rootfiles/packages/qemu b/config/rootfiles/packages/qemu
> index 482087b..3b3f361 100644
> --- a/config/rootfiles/packages/qemu
> +++ b/config/rootfiles/packages/qemu
> @@ -1,3 +1,4 @@
> +lib/udev/rules.d/65-kvm.rules
>  usr/bin/qemu
>  usr/bin/qemu-arm
>  usr/bin/qemu-ga
> diff --git a/lfs/qemu b/lfs/qemu
> index 804ec26..c32953c 100644
> --- a/lfs/qemu
> +++ b/lfs/qemu
> @@ -33,7 +33,7 @@ DIR_APP    = $(DIR_SRC)/$(THISAPP)
>  TARGET     = $(DIR_INFO)/$(THISAPP)
>  SUP_ARCH   = i586 x86_64
>  PROG       = qemu
> -PAK_VER    = 18
> +PAK_VER    = 19
>  
>  DEPS       = "sdl spice"
>  
> @@ -95,6 +95,8 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
>  	paxctl -m -r /usr/bin/qemu-arm
>  	paxctl -m -r /usr/bin/qemu-i386
>  	paxctl -m -r /usr/bin/qemu-x86_64
> +	# install an udev script to set the permissions of /dev/kvm
> +	cp -avf $(DIR_SRC)/config/qemu/65-kvm.rules /lib/udev/rules.d/65-
> kvm.rules
>  
>  	@rm -rf $(DIR_APP)
>  	@$(POSTBUILD)
> diff --git a/src/paks/qemu/install.sh b/src/paks/qemu/install.sh
> index a9f7321..9afe7f9 100644
> --- a/src/paks/qemu/install.sh
> +++ b/src/paks/qemu/install.sh
> @@ -22,6 +22,8 @@
>  ############################################################################
>  #
>  . /opt/pakfire/lib/functions.sh
> +create the group kvm when they not exist

The line above should be a comment...

> +getent group kvm >/dev/null || groupadd kvm
>  extract_files
>  restore_backup ${NAME}
>  echo shm	/dev/shm	tmpfs	defaults,size=256M	0	
> 0 >> /etc/fstab