On 2026/1/26 18:43, Shameer Kolothum wrote:
> During PCI hotplug, in do_pci_register_device(), pci_init_bus_master()
> is called before storing the pci_dev pointer in bus->devices[devfn].
>
> This causes a problem if pci_init_bus_master() (via its
> get_address_space() callback) attempts to retrieve the device using
> pci_find_device(), since the PCI device is not yet visible on the bus.
>
> Fix this by moving the pci_init_bus_master() call to after the device
> has been added to bus->devices[devfn].
>
> This prepares for a subsequent patch where the accel SMMUv3
> get_address_space() callback retrieves the pci_dev to identify the
> attached device type.
>
> No functional change intended.
>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Tested-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
> ---
> hw/pci/pci.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 8cbf5f5d70..229ea7cfb1 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1381,9 +1381,6 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev,
> pci_dev->bus_master_as.max_bounce_buffer_size =
> pci_dev->max_bounce_buffer_size;
>
> - if (phase_check(PHASE_MACHINE_READY)) {
> - pci_init_bus_master(pci_dev);
> - }
> pci_dev->irq_state = 0;
> pci_config_alloc(pci_dev);
>
> @@ -1427,6 +1424,9 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev,
> pci_dev->config_write = config_write;
> bus->devices[devfn] = pci_dev;
> pci_dev->version_id = 2; /* Current pci device vmstate version */
> + if (phase_check(PHASE_MACHINE_READY)) {
> + pci_init_bus_master(pci_dev);
> + }
> return pci_dev;
> }
>