From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40701) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UBTuk-0008Ap-HB for qemu-devel@nongnu.org; Fri, 01 Mar 2013 12:38:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UBTuh-000687-SK for qemu-devel@nongnu.org; Fri, 01 Mar 2013 12:38:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:11002) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UBTuh-00067j-K0 for qemu-devel@nongnu.org; Fri, 01 Mar 2013 12:38:31 -0500 Message-ID: <5130E782.7080204@redhat.com> Date: Fri, 01 Mar 2013 10:38:10 -0700 From: Eric Blake MIME-Version: 1.0 References: <1362130380-1895-1-git-send-email-lilei@linux.vnet.ibm.com> <1362130380-1895-3-git-send-email-lilei@linux.vnet.ibm.com> In-Reply-To: <1362130380-1895-3-git-send-email-lilei@linux.vnet.ibm.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="----enig2FRIMDKBXRVFUSPSGBUOU" Subject: Re: [Qemu-devel] [PATCH 2/2] qga: add guest-set-time command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Lei Li Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2FRIMDKBXRVFUSPSGBUOU Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 03/01/2013 02:33 AM, Lei Li wrote: > Signed-off-by: Lei Li > --- > qga/commands-posix.c | 55 ++++++++++++++++++++++++++++++++++++++++++++= ++++++++ > qga/qapi-schema.json | 27 ++++++++++++++++++++++++++ > 2 files changed, 82 insertions(+) >=20 > diff --git a/qga/commands-posix.c b/qga/commands-posix.c > index f159e25..e246a0d 100644 > --- a/qga/commands-posix.c > +++ b/qga/commands-posix.c > @@ -135,6 +135,61 @@ int64_t qmp_guest_get_time(Error **errp) > return time_ns;=20 > } > =20 > +void qmp_guest_set_time(int64_t time_ns, Error **errp) > +{ > + int ret; > + int status; > + pid_t pid; > + Error *local_err =3D NULL; > + struct timeval tv; > + > + /* year-2038 will overflow in case time_t is 32bit */ > + if ((sizeof(time_t) <=3D 4) && ((unsigned long) time_ns & (1ul << = 31))) { Wrong. If 'unsigned long' and 'time_t' are both 32 bits, but time_ns is 0x1000000000000000, then the cast truncates to 0 and you don't report overflow. Conversely, if time_ns is 0x80000000, you report overflow, even though this value fits in 32-bit time_t after you do division from nanoseconds back to seconds. What you WANT is: if (time_ns / 1000000000 !=3D (time_t)(time_ns / 1000000000)) { > + error_setg_errno(errp, errno, "Invalid time %ld for overflow",= > + time_ns); That wording sounds awkward. Worse, errno is NOT set to anything sane, so you do NOT want error_setg_errno. And %ld is wrong for int64_t on 32-bit platforms. How about: error_setg(errp, "Time %" PRI64D " is too large", time_ns); > +++ b/qga/qapi-schema.json > @@ -99,6 +99,33 @@ > 'returns': 'int' } > =20 > ## > +# @guest-set-time: > +# > +# Set guest time. > +# > +# Right now, when a guest is paused or migrated to a file s/Right now, when/When/ > +# then loaded from that file, the guest OS has no idea that > +# there was a big gap in the time. Depending on how long > +# the gap was, NTP might not be able to resynchronize the > +# guest. > +# > +# This command tries to set guest time based on the information > +# from host or an absolute value given by management app, and > +# set the Hardware Clock to the current System Time. This > +# will make it easier for a guest to resynchronize without > +# waiting for NTP. > +# > +# @time: time of nanoseconds, relative to the Epoch of > +# 1970-01-01 in UTC/GMT. drop '/GMT' > +# > +# Returns: Nothing on success. > +# > +# Since: 1.5 > +## > +{ 'command': 'guest-set-time', > + 'data': { 'time': 'int' } } > + > +## > # @GuestAgentCommandInfo: > # > # Information about guest agent commands. >=20 --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org ------enig2FRIMDKBXRVFUSPSGBUOU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJRMOeCAAoJEKeha0olJ0NqbqgH/Rs1hDJ0b+XaXVEiHkbyNZmE T66XzNFSdWdvtxBQ4i0gI2B16oDuly8bbWnxcpEBbFxBelhDFq+T0JBZC+9cpZoT eXE08G+N3hpSqHC57ER3gS0cnmhtp00QU225JtL6mLSGMNC+agjObHGGgNeaDF4x E10WCZw3GmIDaK+jheG5Pmtz9J4l120NTKqoOa1PkLQatn5Sm4nnN1kh6FRoVvts bV7bs1SJla0/LGL+pVoqMedJTTjSrWjHgD/d0jf+L1/C9ka4QATZFG5jyri9KHYA AYL/ytOHblUmt6ChrBBS9mlbU29rjDAmrTnr1RyjUV+5eWGMBlWp+V1g3QzDvSY= =v/be -----END PGP SIGNATURE----- ------enig2FRIMDKBXRVFUSPSGBUOU--