From ad7aaf34400b1bbd41bbec182fd5895eaad50932 Mon Sep 17 00:00:00 2001

From: Greg Kurz <gkurz@redhat.com>

Date: Tue, 19 Jan 2021 15:09:51 -0500

Subject: [PATCH 3/9] spapr: Don't use spapr_drc_needed() in CAS code

RH-Author: Greg Kurz <gkurz@redhat.com>

Message-id: <20210119150954.1017058-4-gkurz@redhat.com>

Patchwork-id: 100683

O-Subject: [RHEL-8.4.0 qemu-kvm PATCH v2 3/6] spapr: Don't use spapr_drc_needed() in CAS code

Bugzilla: 1901837

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

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

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

From: Greg Kurz <groug@kaod.org>

We currently don't support hotplug of devices between boot and CAS. If

this happens a CAS reboot is triggered. We detect this during CAS using

the spapr_drc_needed() function which is essentially a VMStateDescription

.needed callback. Even if the condition for CAS reboot happens to be the

same as for DRC migration, it looks wrong to piggyback a migration helper

for this.

Introduce a helper with slightly more explicit name and use it in both CAS

and DRC migration code. Since a subsequent patch will enhance this helper

to cover the case of hot unplug, let's go for spapr_drc_transient(). While

here convert spapr_hotplugged_dev_before_cas() to the "transient" wording as

well.

This doesn't change any behaviour.

Signed-off-by: Greg Kurz <groug@kaod.org>

Message-Id: <158169248180.3465937.9531405453362718771.stgit@bahia.lan>

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

(cherry picked from commit 4b63db1289a9e597bc151fa5e4d72f882cb6de1e)

Signed-off-by: Greg Kurz <gkurz@redhat.com>

Signed-off-by: Jon Maloy <jmaloy.redhat.com>

---

 hw/ppc/spapr_drc.c         | 20 ++++++++++++++------

 hw/ppc/spapr_hcall.c       | 14 +++++++++-----

 include/hw/ppc/spapr_drc.h |  4 +++-

 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c

index 62f1a42592..9b498d429e 100644

--- a/hw/ppc/spapr_drc.c

+++ b/hw/ppc/spapr_drc.c

@@ -455,23 +455,31 @@ void spapr_drc_reset(SpaprDrc *drc)

     }

 }

-bool spapr_drc_needed(void *opaque)

+bool spapr_drc_transient(SpaprDrc *drc)

 {

-    SpaprDrc *drc = (SpaprDrc *)opaque;

     SpaprDrcClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);

-    /* If no dev is plugged in there is no need to migrate the DRC state */

+    /*

+     * If no dev is plugged in there is no need to migrate the DRC state

+     * nor to reset the DRC at CAS.

+     */

     if (!drc->dev) {

         return false;

     }

     /*

-     * We need to migrate the state if it's not equal to the expected

-     * long-term state, which is the same as the coldplugged initial

-     * state */

+     * We need to reset the DRC at CAS or to migrate the DRC state if it's

+     * not equal to the expected long-term state, which is the same as the

+     * coldplugged initial state.

+     */

     return (drc->state != drck->ready_state);

 }

+static bool spapr_drc_needed(void *opaque)

+{

+    return spapr_drc_transient(opaque);

+}

+

 static const VMStateDescription vmstate_spapr_drc = {

     .name = "spapr_drc",

     .version_id = 1,

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c

index 0f19be794c..d70e643752 100644

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

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

@@ -1640,20 +1640,24 @@ static uint32_t cas_check_pvr(SpaprMachineState *spapr, PowerPCCPU *cpu,

     return best_compat;

 }

-static bool spapr_hotplugged_dev_before_cas(void)

+static bool spapr_transient_dev_before_cas(void)

 {

-    Object *drc_container, *obj;

+    Object *drc_container;

     ObjectProperty *prop;

     ObjectPropertyIterator iter;

     drc_container = container_get(object_get_root(), "/dr-connector");

     object_property_iter_init(&iter, drc_container);

     while ((prop = object_property_iter_next(&iter))) {

+        SpaprDrc *drc;

+

         if (!strstart(prop->type, "link<", NULL)) {

             continue;

         }

-        obj = object_property_get_link(drc_container, prop->name, NULL);

-        if (spapr_drc_needed(obj)) {

+        drc = SPAPR_DR_CONNECTOR(object_property_get_link(drc_container,

+                                                          prop->name, NULL));

+

+        if (spapr_drc_transient(drc)) {

             return true;

         }

     }

@@ -1812,7 +1816,7 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu,

     spapr_irq_update_active_intc(spapr);

-    if (spapr_hotplugged_dev_before_cas()) {

+    if (spapr_transient_dev_before_cas()) {

         spapr->cas_reboot = true;

     }

diff --git a/include/hw/ppc/spapr_drc.h b/include/hw/ppc/spapr_drc.h

index 83f03cc577..7e09d57114 100644

--- a/include/hw/ppc/spapr_drc.h

+++ b/include/hw/ppc/spapr_drc.h

@@ -269,7 +269,9 @@ int spapr_dt_drc(void *fdt, int offset, Object *owner, uint32_t drc_type_mask);

 void spapr_drc_attach(SpaprDrc *drc, DeviceState *d, Error **errp);

 void spapr_drc_detach(SpaprDrc *drc);

-bool spapr_drc_needed(void *opaque);

+

+/* Returns true if a hot plug/unplug request is pending */

+bool spapr_drc_transient(SpaprDrc *drc);

 static inline bool spapr_drc_unplug_requested(SpaprDrc *drc)

 {

-- 

2.18.2