On Mon, Nov 06, 2017 at 02:14:35PM +1100, Sam Bobroff wrote: > KVM HV will soon support running a guest in hash mode on a POWER9 host > running in radix mode (see [1]), however the guest currently fails to > boot. > > This is because the "htab_shift" value (the size of the MMU's hash > table) is added to the device tree before KVM has had a chance to > change it. If the host is in hash mode, KVM does not need to change it > and so the problem is not seen, but when the host is in radix mode a > change is required and we see a problem. > > To fix this, move the call spapr_setup_hpt_and_vrma() (where > htab_shift could be changed) up a little so that it's called before > spapr_h_cas_compose_response() (where htab_shift is added to the > device tree). > > Signed-off-by: Sam Bobroff <sam.bobr...@au1.ibm.com>
Applied to ppc-for-2.11. > > [1] See http://www.spinics.net/lists/kvm-ppc/msg13057.html > --- > I tested this patch using a kernel based on Paul's kvm-ppc-next branch from > his > powerpc tree: > https://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc.git/ > > hw/ppc/spapr_hcall.c | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c > index 0d59d1534d..be22a6b289 100644 > --- a/hw/ppc/spapr_hcall.c > +++ b/hw/ppc/spapr_hcall.c > @@ -1636,6 +1636,12 @@ static target_ulong > h_client_architecture_support(PowerPCCPU *cpu, > spapr->cas_legacy_guest_workaround = !spapr_ovec_test(ov1_guest, > OV1_PPC_3_00); > if (!spapr->cas_reboot) { > + /* If ppc_spapr_reset() did not set up a HPT but one is necessary > + * (because the guest isn't going to use radix) then set it up here. > */ > + if ((spapr->patb_entry & PATBE1_GR) && !guest_radix) { > + /* legacy hash or new hash: */ > + spapr_setup_hpt_and_vrma(spapr); > + } > spapr->cas_reboot = > (spapr_h_cas_compose_response(spapr, args[1], args[2], > ov5_updates) != 0); > @@ -1644,13 +1650,6 @@ static target_ulong > h_client_architecture_support(PowerPCCPU *cpu, > > if (spapr->cas_reboot) { > qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET); > - } else { > - /* If ppc_spapr_reset() did not set up a HPT but one is necessary > - * (because the guest isn't going to use radix) then set it up here. > */ > - if ((spapr->patb_entry & PATBE1_GR) && !guest_radix) { > - /* legacy hash or new hash: */ > - spapr_setup_hpt_and_vrma(spapr); > - } > } > > return H_SUCCESS; -- 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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