On Tue, Feb 07, 2017 at 01:56:48PM +1100, Sam Bobroff wrote: > Because KVM cannot support radix and hash modes concurrently, QEMU can > avoid allocating a hash page table if KVM supports radix mode. > > Signed-off-by: Sam Bobroff <sam.bobr...@au1.ibm.com>
This isn't quite right, it's doing the HPT handling based on whether
or not we *can* do RPT rather than whether we *are* doing RPT.
It'll mostly work for now, while only radix-on-radix and hash-on-hash
are supported, but that won't be true forever.
It will already be wrong if, for example, you tried to run a POWER8
TCG guest on a host that happened to be a POWER9 in radix mode.
> ---
> hw/ppc/spapr.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index d629e2630c..1411e470c0 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1150,15 +1150,17 @@ static void ppc_spapr_reset(void)
> /* Check for unknown sysbus devices */
> foreach_dynamic_sysbus_device(find_unknown_sysbus_device, NULL);
>
> - /* Allocate and/or reset the hash page table */
> - spapr_reallocate_hpt(spapr,
> + if (!kvmppc_has_cap_mmu_radix()) {
> + /* Allocate and/or reset the hash page table */
> + spapr_reallocate_hpt(spapr,
> spapr_hpt_shift_for_ramsize(machine->maxram_size),
> &error_fatal);
>
> - /* Update the RMA size if necessary */
> - if (spapr->vrma_adjust) {
> - spapr->rma_size = kvmppc_rma_size(spapr_node0_size(),
> - spapr->htab_shift);
> + /* Update the RMA size if necessary */
> + if (spapr->vrma_adjust) {
> + spapr->rma_size = kvmppc_rma_size(spapr_node0_size(),
> + spapr->htab_shift);
> + }
> }
>
> qemu_devices_reset();
--
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
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