From 34e2297e813de18018e4b50e29f8491c78cafe39 Mon Sep 17 00:00:00 2001
From: Laurent Vivier <lvivier@redhat.com>
Date: Tue, 4 Jul 2017 16:32:57 +0200
Subject: [PATCH 2/4] spapr: Add a "no HPT" encoding to HTAB migration stream

RH-Author: Laurent Vivier <lvivier@redhat.com>
Message-id: <20170704163258.9846-3-lvivier@redhat.com>
Patchwork-id: 75705
O-Subject: [Pegas-1.0 qemu-kvm PATCH 2/3] spapr: Add a "no HPT" encoding to HTAB migration stream
Bugzilla: 1456287
RH-Acked-by: David Gibson <dgibson@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Bharata B Rao <bharata@linux.vnet.ibm.com>

Add a "no HPT" encoding (using value -1) to the HTAB migration
stream (in the place of HPT size) when the guest doesn't allocate HPT.
This will help the target side to match target HPT with the source HPT
and thus enable successful migration.

Suggested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
(cherry picked from commit 3a38429748aa4f74abaecf16c4c087e8a325e12a)
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/ppc/spapr.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 2bee3d9..c322666 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1576,13 +1576,19 @@ static int htab_save_setup(QEMUFile *f, void *opaque)
     sPAPRMachineState *spapr = opaque;
 
     /* "Iteration" header */
-    qemu_put_be32(f, spapr->htab_shift);
+    if (!spapr->htab_shift) {
+        qemu_put_be32(f, -1);
+    } else {
+        qemu_put_be32(f, spapr->htab_shift);
+    }
 
     if (spapr->htab) {
         spapr->htab_save_index = 0;
         spapr->htab_first_pass = true;
     } else {
-        assert(kvm_enabled());
+        if (spapr->htab_shift) {
+            assert(kvm_enabled());
+        }
     }
 
 
@@ -1728,7 +1734,12 @@ static int htab_save_iterate(QEMUFile *f, void *opaque)
     int rc = 0;
 
     /* Iteration header */
-    qemu_put_be32(f, 0);
+    if (!spapr->htab_shift) {
+        qemu_put_be32(f, -1);
+        return 0;
+    } else {
+        qemu_put_be32(f, 0);
+    }
 
     if (!spapr->htab) {
         assert(kvm_enabled());
@@ -1762,7 +1773,12 @@ static int htab_save_complete(QEMUFile *f, void *opaque)
     int fd;
 
     /* Iteration header */
-    qemu_put_be32(f, 0);
+    if (!spapr->htab_shift) {
+        qemu_put_be32(f, -1);
+        return 0;
+    } else {
+        qemu_put_be32(f, 0);
+    }
 
     if (!spapr->htab) {
         int rc;
@@ -1806,6 +1822,11 @@ static int htab_load(QEMUFile *f, void *opaque, int version_id)
 
     section_hdr = qemu_get_be32(f);
 
+    if (section_hdr == -1) {
+        spapr_free_hpt(spapr);
+        return 0;
+    }
+
     if (section_hdr) {
         Error *local_err = NULL;
 
-- 
1.8.3.1