Date: Sun, 9 Feb 2014 14:18:50 -0800 From: Craig Rodrigues <rodrigc@FreeBSD.org> To: Aryeh Friedman <aryeh.friedman@gmail.com> Cc: "freebsd-virtualization@freebsd.org" <freebsd-virtualization@freebsd.org> Subject: Re: Detect of BHyve VM was powered off or rebooted? Message-ID: <CAG=rPVcsGG7u_5iuPbn2htvmQBYd=bm_9SE2SuA_ZJtMLKGDoA@mail.gmail.com> In-Reply-To: <CAGBxaX=QiO_eThN3gXoEeRJ%2BBqpuA3kCGayORGhgC7b_yNKYGA@mail.gmail.com> References: <CAG=rPVcfYQ2nUaZYuc6teL2r%2BQZzxhuoV052zgf6=Dxh8MeNcA@mail.gmail.com> <CAGBxaX=QiO_eThN3gXoEeRJ%2BBqpuA3kCGayORGhgC7b_yNKYGA@mail.gmail.com>
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On Sun, Feb 9, 2014 at 1:32 PM, Aryeh Friedman <aryeh.friedman@gmail.com>wrote: > > > > On Sun, Feb 9, 2014 at 4:11 PM, Craig Rodrigues <rodrigc@freebsd.org>wrote: > >> Hi, >> >> I posted some rc.d scripts that I am using to boot a BHyve VM >> and send the output to a serial console using the /dev/nmdm >> driver: >> >> >> http://lists.freebsd.org/pipermail/freebsd-virtualization/2014-January/002040.html >> >> It works quite well. There is some things I would like to improve, >> and would like some advice on the best way to do it. >> >> (1) If the VM was destroyed with bhyvectl --destroy --vm ${VM_NAME}, >> then I do not want to automatically restart the VM in the script. >> User should manually: service bhyvevm start >> >> (2) If the VM was powered down, via shutdown -p, or halt -p, >> then in my script I do not want to restart the VM in the script. >> User should manually: service bhyvevm start >> >> (3) If the VM was rebooted via "reboot" or "shutdown -r", >> then I *do* want the script to restart the VM. >> >> I think if I change my start_vm.sh script to do something like: >> >> >> >> ( >> while [ -e /dev/vmm/${VM} ]; do >> /usr/sbin/bhyve -c 16 -m 8G -A -H -P -g 0 -s 0:0,hostbridge -s 1:0,lpc >> -s 2:0,virtio-net,${TAP} -s 3:0,virtio-blk,${IMG} -l com1,${CONS_A} ${VM}" >> done >> >> ) & >> >> >> then this might cover cases (1) and (3), but what will cover >> case (2)? >> >> Thanks for any advice. >> > > The options you gave (which are really the only ones available) do not > distinguish between the reason for the termination of the instance of bhyve > pointing to /dev/vmm/XXX (it just does a normal termination). > Did you play with any of these flags to bhyvectl? [--get-vmcs-exit-ctls] [--get-vmcs-exit-reason] [--get-vmcs-exit-qualification] [--get-vmcs-exit-interruption-info] If I do: bhyvectl --get-vmcs-exit-reason --vm vm1 I get: vmcs_exit_reason[0] 0x000000000000001e If I look at: http://svnweb.freebsd.org/base/head/sys/amd64/vmm/intel/vmcs.h?view=markup#l310 we have: #define EXIT_REASON_INOUT 30 Linux has this stuff also: http://lxr.free-electrons.com/source/arch/x86/include/asm/vmx.h?v=3.1#L250 so I guess these values are defined in some Intel manual. > In my playing with this for almost a month the only solution seems to be > put a trigger on instance shutdown via whatever method to leave a "cookie" > file behind on the host (note I have not nor plan to do this in any of my > own work). > Yes, I can see why this might need to be done. I might need to do that myself. However, if bhyvectl can be used to provide adequate status information as to why the VM exited, I might be able to avoid this. It would be nicer though if /usr/sbin/bhyve returned the EXIT_REASON in its status code. > > An other question is it wise to auto-reboot regardless of reason of the > hypervisor termination? > I think the answer is "it depends". If someone does "reboot" or "shutdown -r", I think it is reasonable to restart the VM. If someone does "halt -p" or "shutdown -p", I think it is reasonable to not restart the VM. For any other error condition, I think it is reasonable to not restart the VM. I think that there is no single answer for all users and all applications. In my case, I am running BHyve VM's as "headless" which I access via the /dev/nmdm driver. If the VM reboots normally, I want it to restart. -- Craig
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