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From: Ani Sinha <anisinha@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Ani Sinha <anisinha@redhat.com>, qemu-devel@nongnu.org
Subject: [PATCH] hw/pci: add comment explaining the reason for checking function 0 in hotplug
Date: Tue, 20 Jun 2023 19:55:51 +0530	[thread overview]
Message-ID: <20230620142551.115394-1-anisinha@redhat.com> (raw)

This change is cosmetic. A comment is added explaining why we need to check for
the availability of function 0 when we hotplug a device.

CC: mst@redhat.com
Signed-off-by: Ani Sinha <anisinha@redhat.com>
---
 hw/pci/pci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index bf38905b7d..847e534f68 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1179,6 +1179,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev,
                    PCI_SLOT(devfn), PCI_FUNC(devfn), name,
                    bus->devices[devfn]->name, bus->devices[devfn]->qdev.id);
         return NULL;
+    /*
+     * Populating function 0 triggers a scan from the guest that
+     * exposes other non-zero functions. Hence we need to ensure that
+     * function 0 wasn't added yet.
+     */
     } else if (dev->hotplugged &&
                !pci_is_vf(pci_dev) &&
                pci_get_function_0(pci_dev)) {
-- 
2.39.1



             reply	other threads:[~2023-06-20 14:27 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-20 14:25 Ani Sinha [this message]
2023-06-20 22:06 ` [PATCH] hw/pci: add comment explaining the reason for checking function 0 in hotplug Michael S. Tsirkin

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