build/android/install_emulator_deps.py: run kvm-ok as root when needed.

build/android/install_emulator_deps.py: run kvm-ok as root when needed.

This change runs kvm-ok as root after installing the kvm and qemu-kvm
packages to ensure that KVM can work. This gives better diagnostics in
case of failure, which can happen for one of the following reasons:

  - The CPU doesn't support virtualization extensions.
  - The extensions have been disabled by the BIOS.

BUG=NONE
R=yfriedman@chromium.org,navabi@chromium.org,tfarina@chromium.org,raphael.kubo.da.costa@intel.com

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=241708

[navabi, 2013-12-16 19:43:08]

Some places we do kvm-ok without sudo and some places with sudo. Is that
intentional?

https://codereview.chromium.org/116493002/diff/1/build/android/install_emulat...
File build/android/install_emulator_deps.py (right):

https://codereview.chromium.org/116493002/diff/1/build/android/install_emulat...
build/android/install_emulator_deps.py:161: rc = cmd_helper.RunCmd(['sudo',
'kvm-ok'])
Should we just call CheckKVM() here rather than doing "sudo kvm-ok", and then in
CheckKVM() use sudo to get better failure information?

[digit1, 2013-12-17 08:41:43]

https://codereview.chromium.org/116493002/diff/1/build/android/install_emulat...
File build/android/install_emulator_deps.py (right):

https://codereview.chromium.org/116493002/diff/1/build/android/install_emulat...
build/android/install_emulator_deps.py:161: rc = cmd_helper.RunCmd(['sudo',
'kvm-ok'])
Actually, it looks like all /usr/sbin binaries should require root, and aren't
necessarily in a regular user's $PATH. This means we should always call it with
'sudo', I've updated the patch.

This also means that install_emulator_deps.py will always ask for the sudo
password, even if there is nothing to install, if we want to avoid this, we
better just check for /dev/kvm in CheckKVM() instead, which can be done without
root privileges. What do you think?

[navabi, 2013-12-17 21:31:04]

https://codereview.chromium.org/116493002/diff/1/build/android/install_emulat...
File build/android/install_emulator_deps.py (right):

https://codereview.chromium.org/116493002/diff/1/build/android/install_emulat...
build/android/install_emulator_deps.py:161: rc = cmd_helper.RunCmd(['sudo',
'kvm-ok'])
> if we want to avoid this, we better just check
> for /dev/kvm in CheckKVM() instead, which can be
> done without root privileges. What do you think?

I like that idea.

[digit1, 2013-12-18 10:11:10]

On 2013/12/17 21:31:04, navabi wrote:
> I like that idea.

Done, see patch set 3 :-)

[navabi1, 2013-12-18 21:14:22]

lgtm

[navabi1, 2013-12-18 21:14:32]

On 2013/12/18 21:14:22, navabi1 wrote:
> lgtm

Thanks digit!

[commit-bot: I haz the power, 2013-12-18 21:29:41]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/digit@chromium.org/116493002/40001

[commit-bot: I haz the power, 2013-12-18 23:56:09]

Change committed as 241708