From b859b919acc83ea12c5c5b2991afac47e9532660 Mon Sep 17 00:00:00 2001
From: Greg Kurz <gkurz@redhat.com>
Date: Thu, 3 Jun 2021 13:29:40 -0400
Subject: [PATCH 06/21] spapr: Don't hijack current_machine->boot_order
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RH-Author: Miroslav Rezanina <mrezanin@redhat.com>
RH-MergeRequest: 8: Synchronize with RHEL-AV 8.5 release 19 to RHEL 9
RH-Commit: [5/8] 04822ea86e438f013915cd46e09a33627a640a47 (mrezanin/centos-src-qemu-kvm)
RH-Bugzilla: 1957194
RH-Acked-by: Daniel P. Berrangé <berrange@redhat.com>
RH-Acked-by: Greg Kurz <gkurz@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>

From: Greg Kurz <groug@kaod.org>

QEMU 6.0 moved all the -boot variables to the machine. Especially, the
removal of the boot_order static changed the handling of '-boot once'
from:

    if (boot_once) {
        qemu_boot_set(boot_once, &error_fatal);
        qemu_register_reset(restore_boot_order, g_strdup(boot_order));
    }

to

    if (current_machine->boot_once) {
        qemu_boot_set(current_machine->boot_once, &error_fatal);
        qemu_register_reset(restore_boot_order,
                            g_strdup(current_machine->boot_order));
    }

This means that we now register as subsequent boot order a copy
of current_machine->boot_once that was just set with the previous
call to qemu_boot_set(), i.e. we never transition away from the
once boot order.

It is certainly fragile^Wwrong for the spapr code to hijack a
field of the base machine type object like that. The boot order
rework simply turned this software boundary violation into an
actual bug.

Have the spapr code to handle that with its own field in
SpaprMachineState. Also kfree() the initial boot device
string when "once" was used.

Fixes: 4b7acd2ac821 ("vl: clean up -boot variables")
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1960119
Cc: pbonzini@redhat.com
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210521160735.1901914-1-groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
(cherry picked from commit 3bf0844f3be77b24cc8f56fc8df9ff199f8324cb)
Signed-off-by: Greg Kurz <gkurz@redhat.com>

Conflicts:
	include/hw/ppc/spapr.h

Trivial context conflict because downstream has experimental support
for secure guests (f23e4b5090ba).

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/ppc/spapr.c         | 8 +++++---
 include/hw/ppc/spapr.h | 3 +++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 653574ba91..11db32c537 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1006,7 +1006,7 @@ static void spapr_dt_chosen(SpaprMachineState *spapr, void *fdt, bool reset)
     _FDT(chosen = fdt_add_subnode(fdt, 0, "chosen"));
 
     if (reset) {
-        const char *boot_device = machine->boot_order;
+        const char *boot_device = spapr->boot_device;
         char *stdout_path = spapr_vio_stdout_path(spapr->vio_bus);
         size_t cb = 0;
         char *bootlist = get_boot_devices_list(&cb);
@@ -2364,8 +2364,10 @@ static SaveVMHandlers savevm_htab_handlers = {
 static void spapr_boot_set(void *opaque, const char *boot_device,
                            Error **errp)
 {
-    MachineState *machine = MACHINE(opaque);
-    machine->boot_order = g_strdup(boot_device);
+    SpaprMachineState *spapr = SPAPR_MACHINE(opaque);
+
+    g_free(spapr->boot_device);
+    spapr->boot_device = g_strdup(boot_device);
 }
 
 static void spapr_create_lmb_dr_connectors(SpaprMachineState *spapr)
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 54cdde8980..6d15066bc3 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -227,6 +227,9 @@ struct SpaprMachineState {
     /* Secure Guest support via x-svm-allowed */
     bool svm_allowed;
 
+    /* Set by -boot */
+    char *boot_device;
+
     /*< public >*/
     char *kvm_type;
     char *host_model;
-- 
2.27.0