On Tue, Dec 03, 2019 at 02:44:06PM +1100, Alexey Kardashevskiy wrote:
>
>
> On 29/11/2019 12:35, David Gibson wrote:
> > Move the calculation of the Real Mode Area (RMA) size into a helper
> > function. While we're there clean it up and correct it in a few ways:
> > * Add comments making it clearer where the various constraints come from
> > * Remove a pointless check that the RMA fits within Node 0 (we've just
> > clamped it so that it does)
> > * The 16GiB limit we apply is only correct for POWER8, but there is also
> > a 1TiB limit that applies on POWER9.
> >
> > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> > ---
> > hw/ppc/spapr.c | 57 +++++++++++++++++++++++++++++++-------------------
> > 1 file changed, 35 insertions(+), 22 deletions(-)
> >
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index 52c39daa99..7efd4f2b85 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -2664,6 +2664,40 @@ static PCIHostState *spapr_create_default_phb(void)
> > return PCI_HOST_BRIDGE(dev);
> > }
> >
> > +static hwaddr spapr_rma_size(SpaprMachineState *spapr, Error **errp)
> > +{
> > + MachineState *machine = MACHINE(spapr);
> > + hwaddr rma_size = machine->ram_size;
> > + hwaddr node0_size = spapr_node0_size(machine);
> > +
> > + /* RMA has to fit in the first NUMA node */
> > + rma_size = MIN(rma_size, node0_size);
> > +
> > + /*
> > + * VRMA access is via a special 1TiB SLB mapping, so the RMA can
> > + * never exceed that
> > + */
> > + rma_size = MIN(rma_size, TiB);
> > +
> > + /*
> > + * RMA size is controlled in hardware by LPCR[RMLS]. On POWER8
>
>
> RMA is controlled by LPCR on P8 but the RMLS bits on P9 are reserved
> (also reserved in PowerISA 3.0).
>
>
> > + * the largest RMA that can be specified there is 16GiB
>
>
> The P8 user manual says:
> ===
> The following RMO sizes are available for the POWER8 processor.
> The RMLS[34:37] field in the LPCR defines the RMO sizes, as described below.
> 1000 - 32 MB
> 0011 - 64 MB
> 0111 - 128 MB
> 0100 - 256 MB
> 0010 - 1 GB
> 0001 - 16 GB
> 0000 - 256 GB
> ===
>
> The maximum seems to be 256GiB.
Huh. Ok, looks like I was wrong about where that 16GiB clamp came
from originally. I wonder where it *did* come from, or if it's simply
wrong.
> > + */
> > + if (!ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00,
> > + 0, spapr->max_compat_pvr)) {
> > + rma_size = MIN(rma_size, 16 * GiB);
> > + }
> > +
> > + if (rma_size < (MIN_RMA_SLOF * MiB)) {
>
>
> nit: it is time to redefine MIN_RMA_SLOF to use MiBs imho :)
Yeah, I'd thought about that too. I've added a patch to clean that up.
>
>
> > + error_setg(errp,
> > +"pSeries SLOF firmware requires >= %ldMiB guest RMA (Real Mode Area)",
> > + MIN_RMA_SLOF);
>
> Something went wrong with formatting here.
Actually, that's intentional. The idea is to keep the string on one
line for greppability, without going too far to the right. I believe
that's a generally accepted exception to the usual formatting rules in
qemu.
>
> Otherwise looks good. Thanks,
>
>
>
> > + return -1;
> > + }
> > +
> > + return rma_size;
> > +}
> > +
> > /* pSeries LPAR / sPAPR hardware init */
> > static void spapr_machine_init(MachineState *machine)
> > {
> > @@ -2675,7 +2709,6 @@ static void spapr_machine_init(MachineState *machine)
> > int i;
> > MemoryRegion *sysmem = get_system_memory();
> > MemoryRegion *ram = g_new(MemoryRegion, 1);
> > - hwaddr node0_size = spapr_node0_size(machine);
> > long load_limit, fw_size;
> > char *filename;
> > Error *resize_hpt_err = NULL;
> > @@ -2715,20 +2748,7 @@ static void spapr_machine_init(MachineState *machine)
> > exit(1);
> > }
> >
> > - spapr->rma_size = node0_size;
> > -
> > - /* Actually we don't support unbounded RMA anymore since we added
> > - * proper emulation of HV mode. The max we can get is 16G which
> > - * also happens to be what we configure for PAPR mode so make sure
> > - * we don't do anything bigger than that
> > - */
> > - spapr->rma_size = MIN(spapr->rma_size, 0x400000000ull);
> > -
> > - if (spapr->rma_size > node0_size) {
> > - error_report("Numa node 0 has to span the RMA (%#08"HWADDR_PRIx")",
> > - spapr->rma_size);
> > - exit(1);
> > - }
> > + spapr->rma_size = spapr_rma_size(spapr, &error_fatal);
> >
> > /* Setup a load limit for the ramdisk leaving room for SLOF and FDT */
> > load_limit = MIN(spapr->rma_size, RTAS_MAX_ADDR) - FW_OVERHEAD;
> > @@ -2956,13 +2976,6 @@ static void spapr_machine_init(MachineState *machine)
> > }
> > }
> >
> > - if (spapr->rma_size < (MIN_RMA_SLOF * MiB)) {
> > - error_report(
> > - "pSeries SLOF firmware requires >= %ldM guest RMA (Real Mode
> > Area memory)",
> > - MIN_RMA_SLOF);
> > - exit(1);
> > - }
> > -
> > if (kernel_filename) {
> > uint64_t lowaddr = 0;
> >
> >
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature
