From c1ed391fd7e14e16387f8d5e320b13157851db9a Mon Sep 17 00:00:00 2001

From: Suraj Jitindar Singh <sursingh@redhat.com>

Date: Fri, 24 Nov 2017 00:58:16 +0100

Subject: [PATCH 11/15] target/ppc: correct htab shift for hash on radix

RH-Author: Suraj Jitindar Singh <sursingh@redhat.com>

Message-id: <1511485097-25676-2-git-send-email-sursingh@redhat.com>

Patchwork-id: 77845

O-Subject: [RHEL7.5 qemu-kvm-rhev PATCH 1/2] target/ppc: correct htab shift for hash on radix

Bugzilla: 1396120

RH-Acked-by: David Gibson <dgibson@redhat.com>

RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

From: Sam Bobroff <sam.bobroff@au1.ibm.com>

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.bobroff@au1.ibm.com>

[1] See http://www.spinics.net/lists/kvm-ppc/msg13057.html

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

(cherry picked from commit e05fba5004676cd0fa7c47b623cb0a14ad1feed8)

Signed-off-by: Suraj Jitindar Singh <sursingh@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 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 92f1e21..b503299 100644

--- a/hw/ppc/spapr_hcall.c

+++ b/hw/ppc/spapr_hcall.c

@@ -1609,6 +1609,12 @@ 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);

@@ -1617,13 +1623,6 @@ 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;

-- 

1.8.3.1