commit 348e354417b64c484877354ee7cc66f29fa6c7df
author Yuri Benditovich <yuri.benditovich@daynix.com> Fri Jul 28 11:40:49 2023 +0300
committer Michael S. Tsirkin <mst@redhat.com> Thu Aug 03 16:06:49 2023 -0400
tree ee624e8da5dfbc028796b26ad7500dd621fb4fd7
parent c92f4fcafa14890524945073b494937e97112677

pci: do not respond config requests after PCI device eject

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2224964

In migration with VF failover, Windows guest and ACPI hot
unplug we do not need to satisfy config requests, otherwise
the guest immediately detects the device and brings up its
driver. Many network VF's are stuck on the guest PCI bus after
the migration.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Message-Id: <20230728084049.191454-1-yuri.benditovich@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/pci/pci_host.c

diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
index 7af8afd..a18aa0a 100644
--- a/hw/pci/pci_host.c
+++ b/hw/pci/pci_host.c
@@ -62,6 +62,17 @@
     }
 }
 
+static bool is_pci_dev_ejected(PCIDevice *pci_dev)
+{
+    /*
+     * device unplug was requested and the guest acked it,
+     * so we stop responding config accesses even if the
+     * device is not deleted (failover flow)
+     */
+    return pci_dev && pci_dev->partially_hotplugged &&
+           !pci_dev->qdev.pending_deleted_event;
+}
+
 void pci_host_config_write_common(PCIDevice *pci_dev, uint32_t addr,
                                   uint32_t limit, uint32_t val, uint32_t len)
 {
@@ -75,7 +86,7 @@
      * allowing direct removal of unexposed functions.
      */
     if ((pci_dev->qdev.hotplugged && !pci_get_function_0(pci_dev)) ||
-        !pci_dev->has_power) {
+        !pci_dev->has_power || is_pci_dev_ejected(pci_dev)) {
         return;
     }
 
@@ -100,7 +111,7 @@
      * allowing direct removal of unexposed functions.
      */
     if ((pci_dev->qdev.hotplugged && !pci_get_function_0(pci_dev)) ||
-        !pci_dev->has_power) {
+        !pci_dev->has_power || is_pci_dev_ejected(pci_dev)) {
         return ~0x0;
     }