[v5] hw/arm/virt: Add support for user-creatable accelerated SMMUv3

[PATCH v5 07/32] hw/pci/pci: Move pci_init_bus_master() after adding device to bus

Posted by Shameer Kolothum 1 week, 6 days ago

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>
Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
---
 hw/pci/pci.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index c9932c87e3..9693d7f10c 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1370,9 +1370,6 @@ 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);
 
@@ -1416,6 +1413,9 @@ 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;
 }
 
-- 
2.43.0

Re: [PATCH v5 07/32] hw/pci/pci: Move pci_init_bus_master() after adding device to bus

Posted by Eric Auger 1 week, 3 days ago


On 10/31/25 11:49 AM, 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>
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
>  hw/pci/pci.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index c9932c87e3..9693d7f10c 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1370,9 +1370,6 @@ 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);
>  
> @@ -1416,6 +1413,9 @@ 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;
>  }
>

Re: [PATCH v5 07/32] hw/pci/pci: Move pci_init_bus_master() after adding device to bus

Posted by Jonathan Cameron via 1 week, 3 days ago

On Fri, 31 Oct 2025 10:49:40 +0000
Shameer Kolothum <skolothumtho@nvidia.com> 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>
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
Seems harmless.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

> ---
>  hw/pci/pci.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index c9932c87e3..9693d7f10c 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1370,9 +1370,6 @@ 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);
>  
> @@ -1416,6 +1413,9 @@ 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;
>  }
>