From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52618) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dXC6X-0000Li-SW for qemu-devel@nongnu.org; Mon, 17 Jul 2017 15:54:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dXC6V-0001Uf-2w for qemu-devel@nongnu.org; Mon, 17 Jul 2017 15:54:53 -0400 References: <20170630104632.27942-1-david@gibson.dropbear.id.au> <20170630104632.27942-7-david@gibson.dropbear.id.au> From: Laurent Vivier Message-ID: Date: Mon, 17 Jul 2017 21:54:45 +0200 MIME-Version: 1.0 In-Reply-To: <20170630104632.27942-7-david@gibson.dropbear.id.au> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-ppc] [PULL 06/21] spapr: Add a "no HPT" encoding to HTAB migration stream List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson , peter.maydell@linaro.org Cc: thuth@redhat.com, qemu-devel@nongnu.org, sursingh@redhat.com, mdroth@linux.vnet.ibm.com, qemu-ppc@nongnu.org, Bharata B Rao , sbobroff@redhat.com On 30/06/2017 12:46, David Gibson wrote: > From: Bharata B Rao > > Add a "no HPT" encoding (using value -1) to the HTAB migration > stream (in the place of HPT size) when the guest doesn't allocate HPT. > This will help the target side to match target HPT with the source HPT > and thus enable successful migration. > > Suggested-by: David Gibson > Signed-off-by: Bharata B Rao > Signed-off-by: David Gibson > --- > hw/ppc/spapr.c | 29 +++++++++++++++++++++++++---- > 1 file changed, 25 insertions(+), 4 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 52f4e72..f3e0b9b 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -1560,13 +1560,19 @@ static int htab_save_setup(QEMUFile *f, void *opaque) > sPAPRMachineState *spapr = opaque; > > /* "Iteration" header */ > - qemu_put_be32(f, spapr->htab_shift); > + if (!spapr->htab_shift) { > + qemu_put_be32(f, -1); > + } else { > + qemu_put_be32(f, spapr->htab_shift); > + } > > if (spapr->htab) { > spapr->htab_save_index = 0; > spapr->htab_first_pass = true; > } else { > - assert(kvm_enabled()); > + if (spapr->htab_shift) { > + assert(kvm_enabled()); > + } > } > > > @@ -1712,7 +1718,12 @@ static int htab_save_iterate(QEMUFile *f, void *opaque) > int rc = 0; > > /* Iteration header */ > - qemu_put_be32(f, 0); > + if (!spapr->htab_shift) { > + qemu_put_be32(f, -1); > + return 0; > + } else { > + qemu_put_be32(f, 0); > + } > > if (!spapr->htab) { > assert(kvm_enabled()); > @@ -1746,7 +1757,12 @@ static int htab_save_complete(QEMUFile *f, void *opaque) > int fd; > > /* Iteration header */ > - qemu_put_be32(f, 0); > + if (!spapr->htab_shift) { > + qemu_put_be32(f, -1); > + return 0; > + } else { > + qemu_put_be32(f, 0); > + } > > if (!spapr->htab) { > int rc; > @@ -1790,6 +1806,11 @@ static int htab_load(QEMUFile *f, void *opaque, int version_id) > > section_hdr = qemu_get_be32(f); > > + if (section_hdr == -1) { > + spapr_free_hpt(spapr); > + return 0; > + } > + > if (section_hdr) { > Error *local_err = NULL; > > It seems there is a bug in this patch: when using from QEMU console the command "savevm", it never stops and the qcow2 image grows without limit. I think this is because htab_save_iterate() and htab_save_complete() should mark the end of the sequence (the empty one, -1) by returning 1 and not 0 (see kvmppc_save_htab()). This fixes the problem for me: diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 970093e..fa01511 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -1827,7 +1827,7 @@ static int htab_save_iterate(QEMUFile *f, void *opaque) /* Iteration header */ if (!spapr->htab_shift) { qemu_put_be32(f, -1); - return 0; + return 1; } else { qemu_put_be32(f, 0); } @@ -1866,7 +1866,7 @@ static int htab_save_complete(QEMUFile *f, void *opaque) /* Iteration header */ if (!spapr->htab_shift) { qemu_put_be32(f, -1); - return 0; + return 1; } else { qemu_put_be32(f, 0); } Laurent