From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57332) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VbtPN-0005Q8-4C for qemu-devel@nongnu.org; Thu, 31 Oct 2013 10:39:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VbtPI-0007nF-3k for qemu-devel@nongnu.org; Thu, 31 Oct 2013 10:39:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14126) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VbtPH-0007mv-RZ for qemu-devel@nongnu.org; Thu, 31 Oct 2013 10:39:32 -0400 Message-ID: <52726B95.6020006@redhat.com> Date: Thu, 31 Oct 2013 15:39:17 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1377187852-11192-1-git-send-email-pbonzini@redhat.com> <20131024023903.GD16757@G08FNSTD100614.fnst.cn.fujitsu.com> <20131031143004.GA9948@redhat.com> <52726A0B.4080805@redhat.com> In-Reply-To: <52726A0B.4080805@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] pvpanic plans? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: pkrempa@redhat.com, marcel.a@redhat.com, libvir-list@redhat.com, Hu Tao , "Michael S. Tsirkin" , qemu-devel@nongnu.org, armbru@redhat.com, rhod@redhat.com, kraxel@redhat.com, anthony@codemonkey.ws, lcapitulino@redhat.com, lersek@redhat.com, afaerber@suse.de -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Il 31/10/2013 15:32, Eric Blake ha scritto: > On 10/31/2013 08:30 AM, Michael S. Tsirkin wrote: >> On Thu, Oct 24, 2013 at 10:39:03AM +0800, Hu Tao wrote: >>> Hi All, >>> >>> I know it's been a long time since this thread. But qemu 1.7 is >>> releasing, do you have any consensus on this? >> >> I think the biggest issue is the new PANICKED state. Guests >> already have simple ways to halt the CPU, and actually do. I >> think a new state was a mistake. So how about the following? >> Does it break anything? (Untested). > > Don't you still need to halt the guest on a panic event, for > management to have a chance to choose what to do about the panic? > I'm suspecting this patch does break things. Yes, it does. But I think that, once we make the pvpanic device is optional, to a large extent there is no bug. Adding the pvpanic device to the VM will make libvirt obey instead of the in-guest setting, and that's it. Two months have passed and no casualties have been reported due to pvpanic. Let's just remove the auto-pvpanic from all machine types in 1.7 (yes, that's backwards incompatible in a strict sense), document it in the release notes, and hope that the old QEMU versions with mandatory pvpanic die of old age. All the advantages/disadvantages from my original messages still apply. Let's ignore the disadvantages and just KISS. Paolo -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJScmuVAAoJEBvWZb6bTYbyS6MP/Rb9japkUmjKy+bUW2Bf5vHD hOrCL/20LC17OdIdzOngjfcY6OyPrtZ6dtjzvSjsWoxjW+QNuTwLM5h+0kOmvlM/ UCqX9MZiKFysVphnwIFy2fzTKmAVw5WqUlS17XMsiKxpvCquy5Fss5PWB3k3orMD kRCoTTmQDID95T38OqezvzDaRjNvoHXOTuWFOhbzWt2OFUwg1WDy1GLKV/pSx0/o GS2/RYo5iQkEtZk0muj0fmWEZX1K2nfaYmVQh39LJhFrWQLabHskYz1+n/OTmwQT 3DiUkfeqrxLahlyHbIOguLjLY8gH2fZa0gzHEB7D0b1aiuqQmsxM3ELdl8pJJzex 1ZGKt9X1u58v/SvfDHW14uCMAiv8jgQDnDOa6pgi7DezBQym+90+RnzC2Z5BcHIp hsPEB0Bc47REPu69GOSj7XQ1uan5yQS38jSv8D11nJEW8VfXiV4smOZhivrEOicR mdYYV6BNc985vcVOmvmkTJ5VkUOKeMzMDAJkSDqN6P0fQKTOJpCtJag3TcjHVRB4 ORXUrdO9NuICGjwB75T86INkxEsXFaw1aHIKpcxMk2PN6u/Zc+n7GXf65ReGorbL 2QUrepzUUt+mTYXJha9h7gEudRnixe5zK8AgqtSHAJPKP++LrFz4lrmzCHC6e3V1 6K2AhZl4EjBJaf6AMy70 =GBBt -----END PGP SIGNATURE-----