From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40458) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAZyy-000464-Sx for qemu-devel@nongnu.org; Thu, 11 Oct 2018 08:22:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAZyy-0003nh-0o for qemu-devel@nongnu.org; Thu, 11 Oct 2018 08:22:24 -0400 Received: from mail-qt1-x843.google.com ([2607:f8b0:4864:20::843]:40719) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gAZyx-0003nU-SV for qemu-devel@nongnu.org; Thu, 11 Oct 2018 08:22:23 -0400 Received: by mail-qt1-x843.google.com with SMTP id b4-v6so9498092qtc.7 for ; Thu, 11 Oct 2018 05:22:23 -0700 (PDT) References: <20180918185246.18109-1-danielhb413@gmail.com> <20180918185246.18109-3-danielhb413@gmail.com> <875zy97wxp.fsf@dusky.pond.sub.org> From: Daniel Henrique Barboza Message-ID: Date: Thu, 11 Oct 2018 09:22:18 -0300 MIME-Version: 1.0 In-Reply-To: <875zy97wxp.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Subject: Re: [Qemu-devel] [PATCH v9 2/3] qga: update guest-suspend-ram and guest-suspend-hybrid descriptions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: qemu-devel@nongnu.org, ehabkost@redhat.com, mst@redhat.com, mdroth@linux.vnet.ibm.com, imammedo@redhat.com On 10/11/18 4:40 AM, Markus Armbruster wrote: > Daniel Henrique Barboza writes: > >> This patch updates the descriptions of 'guest-suspend-ram' and >> 'guest-suspend-hybrid' to mention that both commands relies now >> on the proper support for wake up from suspend, retrieved by the >> 'wakeup-suspend-support' attribute of the 'query-current-machine' >> QMP command. >> >> Reported-by: Balamuruhan S >> Signed-off-by: Daniel Henrique Barboza >> Reviewed-by: Michael Roth >> --- >> qga/qapi-schema.json | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json >> index dfbc4a5e32..7ae7e2502c 100644 >> --- a/qga/qapi-schema.json >> +++ b/qga/qapi-schema.json >> @@ -567,9 +567,9 @@ >> # For the best results it's strongly recommended to have the pm-utils >> # package installed in the guest. >> # >> -# IMPORTANT: guest-suspend-ram requires QEMU to support the 'system_wakeup' >> -# command. Thus, it's *required* to query QEMU for the presence of the >> -# 'system_wakeup' command before issuing guest-suspend-ram. >> +# IMPORTANT: guest-suspend-ram requires working wakeup support in >> +# QEMU. You *must* check QMP command query-current-machine returns >> +# wakeup-suspend-support: true before issuing this command. >> # >> # This command does NOT return a response on success. There are two options >> # to check for success: >> @@ -594,9 +594,9 @@ >> # >> # This command requires the pm-utils package to be installed in the guest. >> # >> -# IMPORTANT: guest-suspend-hybrid requires QEMU to support the 'system_wakeup' >> -# command. Thus, it's *required* to query QEMU for the presence of the >> -# 'system_wakeup' command before issuing guest-suspend-hybrid. >> +# IMPORTANT: guest-suspend-hybrid requires working wakeup support in >> +# QEMU. You *must* check QMP command query-current-machine returns >> +# wakeup-suspend-support: true before issuing this command. >> # >> # This command does NOT return a response on success. There are two options >> # to check for success: > The emphasis in "You *must* check" hints at all kinds of terrible > disasters if you don't, but then you're not pointing to any. > > So, what can happen if you issue this command when query-current-machine > returns wakeup-suspend-support: false? That's fair. If you don't check for flag when issuing guest-suspend-{ram/hybrid}, what happens is that QEMU will suspend the guest (QGA will suspend the guest via systemctl, regardless of the guest arch) but system_wakeup will not be able to wake the guest back up. You'll need to reboot the guest. What  do you think of this new text? +# IMPORTANT: guest-suspend-hybrid requires working wakeup support in +# QEMU. You *must* check QMP command query-current-machine returns +# wakeup-suspend-support: true before issuing this command. Failure in +# doing so can result in a suspended guest that QEMU will not be able to +# awaken, forcing the user to power cycle the guest to bring it back.