| Message ID | 1453178361-24244-1-git-send-email-bharata@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jan 19, 2016 at 10:09:21AM +0530, Bharata B Rao wrote: > If guest doesn't have any dynamically reconfigurable (DR) logical memory > blocks (LMB), then we shouldn't create ibm,dynamic-reconfiguration-memory > device tree node. > > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > --- > This applies against ppc-for-2.6 branch of David Gibson's tree. Applied to ppc-for-2.6, thanks. > > hw/ppc/spapr.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 50e5a26..86e5023 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -763,6 +763,13 @@ static int spapr_populate_drconf_memory(sPAPRMachineState *spapr, void *fdt) > int nr_nodes = nb_numa_nodes ? nb_numa_nodes : 1; > > /* > + * Don't create the node if there are no DR LMBs. > + */ > + if (!nr_lmbs) { > + return 0; > + } > + > + /* > * Allocate enough buffer size to fit in ibm,dynamic-memory > * or ibm,associativity-lookup-arrays > */ > @@ -868,7 +875,7 @@ int spapr_h_cas_compose_response(sPAPRMachineState *spapr, > _FDT((spapr_fixup_cpu_dt(fdt, spapr))); > } > > - /* Generate memory nodes or ibm,dynamic-reconfiguration-memory node */ > + /* Generate ibm,dynamic-reconfiguration-memory node if required */ > if (memory_update && smc->dr_lmb_enabled) { > _FDT((spapr_populate_drconf_memory(spapr, fdt))); > }
On Tue, Jan 19, 2016 at 04:00:25PM +1100, David Gibson wrote: > On Tue, Jan 19, 2016 at 10:09:21AM +0530, Bharata B Rao wrote: > > If guest doesn't have any dynamically reconfigurable (DR) logical memory > > blocks (LMB), then we shouldn't create ibm,dynamic-reconfiguration-memory > > device tree node. > > > > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > > --- > > This applies against ppc-for-2.6 branch of David Gibson's tree. > > Applied to ppc-for-2.6, thanks. There is a slight change in memory nodes representation in DT after this fix that could result in the following behaviour before and after migration. For a guest with -m 4G -numa node,nodeid=0,mem=2G -numa node,nodeid=1,mem=2G, the DT under /proc/device-tree changes like this: Guest started with QEMU w/o this fix ------------------------------------ memory@0 memory@80000000 ibm,dynamic-reconfiguration-memory Guest migrated to QEMU w/ this fix included ------------------------------------------- memory@0 memory@80000000 ibm,dynamic-reconfiguration-memory After next reboot ----------------- memory@0 memory@80000000 I guess this is ok, but wanted to sound out this change explicitly. Regards, Bharata.
On Wed, Jan 20, 2016 at 11:00:39AM +0530, Bharata B Rao wrote: > On Tue, Jan 19, 2016 at 04:00:25PM +1100, David Gibson wrote: > > On Tue, Jan 19, 2016 at 10:09:21AM +0530, Bharata B Rao wrote: > > > If guest doesn't have any dynamically reconfigurable (DR) logical memory > > > blocks (LMB), then we shouldn't create ibm,dynamic-reconfiguration-memory > > > device tree node. > > > > > > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > > > --- > > > This applies against ppc-for-2.6 branch of David Gibson's tree. > > > > Applied to ppc-for-2.6, thanks. > > There is a slight change in memory nodes representation in DT after this fix > that could result in the following behaviour before and after migration. > > For a guest with -m 4G -numa node,nodeid=0,mem=2G -numa node,nodeid=1,mem=2G, > the DT under /proc/device-tree changes like this: > > Guest started with QEMU w/o this fix > ------------------------------------ > memory@0 > memory@80000000 > ibm,dynamic-reconfiguration-memory > > Guest migrated to QEMU w/ this fix included > ------------------------------------------- > memory@0 > memory@80000000 > ibm,dynamic-reconfiguration-memory > > After next reboot > ----------------- > memory@0 > memory@80000000 > > I guess this is ok, but wanted to sound out this change explicitly. Yeah, I think that should be ok. Generally device tree changes won't break migration, because the guest (or SLOF) will have already grabbed the old device tree from the source qemu.
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 50e5a26..86e5023 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -763,6 +763,13 @@ static int spapr_populate_drconf_memory(sPAPRMachineState *spapr, void *fdt) int nr_nodes = nb_numa_nodes ? nb_numa_nodes : 1; /* + * Don't create the node if there are no DR LMBs. + */ + if (!nr_lmbs) { + return 0; + } + + /* * Allocate enough buffer size to fit in ibm,dynamic-memory * or ibm,associativity-lookup-arrays */ @@ -868,7 +875,7 @@ int spapr_h_cas_compose_response(sPAPRMachineState *spapr, _FDT((spapr_fixup_cpu_dt(fdt, spapr))); } - /* Generate memory nodes or ibm,dynamic-reconfiguration-memory node */ + /* Generate ibm,dynamic-reconfiguration-memory node if required */ if (memory_update && smc->dr_lmb_enabled) { _FDT((spapr_populate_drconf_memory(spapr, fdt))); }
If guest doesn't have any dynamically reconfigurable (DR) logical memory blocks (LMB), then we shouldn't create ibm,dynamic-reconfiguration-memory device tree node. Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> --- This applies against ppc-for-2.6 branch of David Gibson's tree. hw/ppc/spapr.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)