qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Greg Kurz <groug@kaod.org>
To: qemu-devel@nongnu.org
Cc: Daniel Henrique Barboza <danielhb@linux.ibm.com>,
	qemu-ppc@nongnu.org, Greg Kurz <groug@kaod.org>,
	David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 4/6] spapr: Use spapr_drc_reset_all() at machine reset
Date: Fri, 18 Dec 2020 11:33:58 +0100	[thread overview]
Message-ID: <20201218103400.689660-5-groug@kaod.org> (raw)
In-Reply-To: <20201218103400.689660-1-groug@kaod.org>

Documentation of object_child_foreach_recursive() clearly stipulates
that "it is forbidden to add or remove children from @obj from the @fn
callback". But this is exactly what we do during machine reset. The call
to spapr_drc_reset() can finalize the hot-unplug sequence of a PHB or a
PCI bridge, both of which will then in turn destroy their PCI DRCs. This
could potentially invalidate the iterator used by do_object_child_foreach().
It is pure luck that this haven't caused any issues so far.

Use spapr_drc_reset_all() since it can cope with DRC removal.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/ppc/spapr.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 43dded87f498..8528bc90fec4 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1566,19 +1566,6 @@ void spapr_setup_hpt(SpaprMachineState *spapr)
     }
 }
 
-static int spapr_reset_drcs(Object *child, void *opaque)
-{
-    SpaprDrc *drc =
-        (SpaprDrc *) object_dynamic_cast(child,
-                                                 TYPE_SPAPR_DR_CONNECTOR);
-
-    if (drc) {
-        spapr_drc_reset(drc);
-    }
-
-    return 0;
-}
-
 static void spapr_machine_reset(MachineState *machine)
 {
     SpaprMachineState *spapr = SPAPR_MACHINE(machine);
@@ -1633,7 +1620,7 @@ static void spapr_machine_reset(MachineState *machine)
      * will crash QEMU if the DIMM holding the vring goes away). To avoid such
      * situations, we reset DRCs after all devices have been reset.
      */
-    object_child_foreach_recursive(object_get_root(), spapr_reset_drcs, NULL);
+    spapr_drc_reset_all(spapr);
 
     spapr_clear_pending_events(spapr);
 
-- 
2.26.2



  parent reply	other threads:[~2020-12-18 10:41 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-18 10:33 [PATCH 0/6] spapr: Fix visibility and traversal of DR connectors Greg Kurz
2020-12-18 10:33 ` [PATCH 1/6] spapr: Call spapr_drc_reset() for all DRCs at CAS Greg Kurz
2020-12-21 18:24   ` Daniel Henrique Barboza
2020-12-28  7:20   ` David Gibson
2020-12-18 10:33 ` [PATCH 2/6] spapr: Fix reset of transient DR connectors Greg Kurz
2020-12-21 20:34   ` Daniel Henrique Barboza
2020-12-28  7:24   ` David Gibson
2020-12-18 10:33 ` [PATCH 3/6] spapr: Introduce spapr_drc_reset_all() Greg Kurz
2020-12-21 20:35   ` Daniel Henrique Barboza
2020-12-28  7:26   ` David Gibson
2020-12-18 10:33 ` Greg Kurz [this message]
2020-12-21 20:36   ` [PATCH 4/6] spapr: Use spapr_drc_reset_all() at machine reset Daniel Henrique Barboza
2020-12-28  7:29   ` David Gibson
2020-12-18 10:33 ` [PATCH 5/6] spapr: Add drc_ prefix to the DRC realize and unrealize functions Greg Kurz
2020-12-21 20:37   ` Daniel Henrique Barboza
2020-12-28  7:31   ` David Gibson
2020-12-18 10:34 ` [PATCH 6/6] spapr: Model DR connectors as simple objects Greg Kurz
2020-12-21 20:45   ` Daniel Henrique Barboza
2020-12-28  8:28   ` David Gibson
2021-01-06 18:15     ` Greg Kurz
2021-02-08  6:30       ` David Gibson
2020-12-22 10:14 ` [PATCH 0/6] spapr: Fix visibility and traversal of DR connectors Daniel Henrique Barboza

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201218103400.689660-5-groug@kaod.org \
    --to=groug@kaod.org \
    --cc=danielhb@linux.ibm.com \
    --cc=david@gibson.dropbear.id.au \
    --cc=qemu-devel@nongnu.org \
    --cc=qemu-ppc@nongnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).