Commit 0dabc0f6 authored by Julia Suvorova's avatar Julia Suvorova Committed by Michael S. Tsirkin
Browse files

hw/pci/pcie: Move hot plug capability check to pre_plug callback 



Check for hot plug capability earlier to avoid removing devices attached
during the initialization process.

Run qemu with an unattached drive:
  -drive file=$FILE,if=none,id=drive0 \
  -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off
Hotplug a block device:
  device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0
If hotplug fails on plug_cb, drive0 will be deleted.

Fixes: 0501e1aa ("hw/pci/pcie: Forbid hot-plug if it's disabled on the slot")

Acked-by: default avatarIgor Mammedov <imammedo@redhat.com>
Signed-off-by: default avatarJulia Suvorova <jusual@redhat.com>
Message-Id: <20200604125947.881210-1-jusual@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent b963ea19

hw/pci/pcie.c

+11 −8
Original line number Diff line number Diff line
@@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev, 
void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,

                               Error **errp)

{

    PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);

    uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;

    uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP);



    /* Check if hot-plug is disabled on the slot */

    if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) {

        error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'",

                         DEVICE(hotplug_pdev)->id);

        return;

    }



    pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp);

}
@@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, 
{

    PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);

    uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;

    uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP);

    PCIDevice *pci_dev = PCI_DEVICE(dev);



    /* Don't send event when device is enabled during qemu machine creation:
@@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, 
        return;

    }



    /* Check if hot-plug is disabled on the slot */

    if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) {

        error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'",

                         DEVICE(hotplug_pdev)->id);

        return;

    }



    /* To enable multifunction hot-plug, we just ensure the function

     * 0 added last. When function 0 is added, we set the sltsta and

     * inform OS via event notification.