Re: [PATCH v2 05/29] vfio: export PCI helpers needed for vfio-user

["Cédric Le Goater" <clg@redhat.com>]

On 5/20/25 17:03, John Levon wrote:
> The vfio-user code will need to re-use various parts of the vfio PCI
> code. Export them in hw/vfio/pci.h, and rename them to the vfio_pci_*
> namespace.
> 
> Signed-off-by: John Levon <john.levon@nutanix.com>
> ---
>   hw/vfio/pci.h        | 14 ++++++++++++
>   hw/vfio/pci.c        | 54 ++++++++++++++++++++++----------------------
>   hw/vfio/trace-events |  6 ++---
>   3 files changed, 44 insertions(+), 30 deletions(-)
> 
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index 5ce0fb916f..61fa385ddb 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -248,4 +248,18 @@ void vfio_display_finalize(VFIOPCIDevice *vdev);
>   
>   extern const VMStateDescription vfio_display_vmstate;
>   
> +void vfio_pci_bars_exit(VFIOPCIDevice *vdev);
> +bool vfio_pci_add_capabilities(VFIOPCIDevice *vdev, Error **errp);
> +bool vfio_pci_config_setup(VFIOPCIDevice *vdev, Error **errp);
> +Object *vfio_pci_get_object(VFIODevice *vbasedev);
> +bool vfio_pci_interrupt_setup(VFIOPCIDevice *vdev, Error **errp);
> +void vfio_pci_intx_eoi(VFIODevice *vbasedev);
> +int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f);
> +void vfio_pci_put_device(VFIOPCIDevice *vdev);
> +bool vfio_pci_populate_device(VFIOPCIDevice *vdev, Error **errp);
> +void vfio_pci_register_err_notifier(VFIOPCIDevice *vdev);
> +void vfio_pci_register_req_notifier(VFIOPCIDevice *vdev);
> +int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error **errp);
> +void vfio_pci_teardown_msi(VFIOPCIDevice *vdev);
> +

The rename is a good thing. There are more to be done.

One comment,

These routines :

   Object *vfio_pci_get_object(VFIODevice *vbasedev);
   void vfio_pci_intx_eoi(VFIODevice *vbasedev);
   int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f);
   int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error **errp);

are exported to simply define the VFIODeviceOps vfio_user_pci_ops struct
(and they don't take a VFIOPCIDevice as first argument). I wonder if we
could find a way to keep them private.

Also, does vfio-user support migration ? if not then, we only need to
export vfio_pci_intx_eoi()


Thanks,

C.




>   #endif /* HW_VFIO_VFIO_PCI_H */
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index b1250d85bf..5159198bdb 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -103,7 +103,7 @@ static void vfio_intx_interrupt(void *opaque)
>       }
>   }
>   
> -static void vfio_intx_eoi(VFIODevice *vbasedev)
> +void vfio_pci_intx_eoi(VFIODevice *vbasedev)
>   {
>       VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>   
> @@ -111,7 +111,7 @@ static void vfio_intx_eoi(VFIODevice *vbasedev)
>           return;
>       }
>   
> -    trace_vfio_intx_eoi(vbasedev->name);
> +    trace_vfio_pci_intx_eoi(vbasedev->name);
>   
>       vdev->intx.pending = false;
>       pci_irq_deassert(&vdev->pdev);
> @@ -236,7 +236,7 @@ static void vfio_intx_update(VFIOPCIDevice *vdev, PCIINTxRoute *route)
>       }
>   
>       /* Re-enable the interrupt in cased we missed an EOI */
> -    vfio_intx_eoi(&vdev->vbasedev);
> +    vfio_pci_intx_eoi(&vdev->vbasedev);
>   }
>   
>   static void vfio_intx_routing_notifier(PCIDevice *pdev)
> @@ -1743,7 +1743,7 @@ static bool vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
>       return true;
>   }
>   
> -static void vfio_teardown_msi(VFIOPCIDevice *vdev)
> +void vfio_pci_teardown_msi(VFIOPCIDevice *vdev)
>   {
>       msi_uninit(&vdev->pdev);
>   
> @@ -1839,7 +1839,7 @@ static void vfio_bars_register(VFIOPCIDevice *vdev)
>       }
>   }
>   
> -static void vfio_bars_exit(VFIOPCIDevice *vdev)
> +void vfio_pci_bars_exit(VFIOPCIDevice *vdev)
>   {
>       int i;
>   
> @@ -2430,7 +2430,7 @@ static void vfio_add_ext_cap(VFIOPCIDevice *vdev)
>       g_free(config);
>   }
>   
> -static bool vfio_add_capabilities(VFIOPCIDevice *vdev, Error **errp)
> +bool vfio_pci_add_capabilities(VFIOPCIDevice *vdev, Error **errp)
>   {
>       PCIDevice *pdev = &vdev->pdev;
>   
> @@ -2599,7 +2599,7 @@ static void vfio_pci_compute_needs_reset(VFIODevice *vbasedev)
>       }
>   }
>   
> -static Object *vfio_pci_get_object(VFIODevice *vbasedev)
> +Object *vfio_pci_get_object(VFIODevice *vbasedev)
>   {
>       VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>   
> @@ -2655,7 +2655,7 @@ static const VMStateDescription vmstate_vfio_pci_config = {
>       }
>   };
>   
> -static int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error **errp)
> +int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error **errp)
>   {
>       VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>   
> @@ -2663,7 +2663,7 @@ static int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error **errp)
>                                          errp);
>   }
>   
> -static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
> +int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
>   {
>       VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>       PCIDevice *pdev = &vdev->pdev;
> @@ -2706,7 +2706,7 @@ static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
>   static VFIODeviceOps vfio_pci_ops = {
>       .vfio_compute_needs_reset = vfio_pci_compute_needs_reset,
>       .vfio_hot_reset_multi = vfio_pci_hot_reset_multi,
> -    .vfio_eoi = vfio_intx_eoi,
> +    .vfio_eoi = vfio_pci_intx_eoi,
>       .vfio_get_object = vfio_pci_get_object,
>       .vfio_save_config = vfio_pci_save_config,
>       .vfio_load_config = vfio_pci_load_config,
> @@ -2777,7 +2777,7 @@ bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
>       return true;
>   }
>   
> -static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
> +bool vfio_pci_populate_device(VFIOPCIDevice *vdev, Error **errp)
>   {
>       VFIODevice *vbasedev = &vdev->vbasedev;
>       struct vfio_region_info *reg_info = NULL;
> @@ -2823,7 +2823,7 @@ static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
>           return false;
>       }
>   
> -    trace_vfio_populate_device_config(vdev->vbasedev.name,
> +    trace_vfio_pci_populate_device_config(vdev->vbasedev.name,
>                                         (unsigned long)reg_info->size,
>                                         (unsigned long)reg_info->offset,
>                                         (unsigned long)reg_info->flags);
> @@ -2845,7 +2845,7 @@ static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
>       ret = vfio_device_get_irq_info(vbasedev, VFIO_PCI_ERR_IRQ_INDEX, &irq_info);
>       if (ret) {
>           /* This can fail for an old kernel or legacy PCI dev */
> -        trace_vfio_populate_device_get_irq_info_failure(strerror(-ret));
> +        trace_vfio_pci_populate_device_get_irq_info_failure(strerror(-ret));
>       } else if (irq_info.count == 1) {
>           vdev->pci_aer = true;
>       } else {
> @@ -2857,7 +2857,7 @@ static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
>       return true;
>   }
>   
> -static void vfio_pci_put_device(VFIOPCIDevice *vdev)
> +void vfio_pci_put_device(VFIOPCIDevice *vdev)
>   {
>       vfio_display_finalize(vdev);
>       vfio_bars_finalize(vdev);
> @@ -2905,7 +2905,7 @@ static void vfio_err_notifier_handler(void *opaque)
>    * and continue after disabling error recovery support for the
>    * device.
>    */
> -static void vfio_register_err_notifier(VFIOPCIDevice *vdev)
> +void vfio_pci_register_err_notifier(VFIOPCIDevice *vdev)
>   {
>       Error *err = NULL;
>       int32_t fd;
> @@ -2964,7 +2964,7 @@ static void vfio_req_notifier_handler(void *opaque)
>       }
>   }
>   
> -static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
> +void vfio_pci_register_req_notifier(VFIOPCIDevice *vdev)
>   {
>       struct vfio_irq_info irq_info;
>       Error *err = NULL;
> @@ -3018,7 +3018,7 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev)
>       vdev->req_enabled = false;
>   }
>   
> -static bool vfio_pci_config_setup(VFIOPCIDevice *vdev, Error **errp)
> +bool vfio_pci_config_setup(VFIOPCIDevice *vdev, Error **errp)
>   {
>       PCIDevice *pdev = &vdev->pdev;
>       VFIODevice *vbasedev = &vdev->vbasedev;
> @@ -3124,7 +3124,7 @@ static bool vfio_pci_config_setup(VFIOPCIDevice *vdev, Error **errp)
>       return true;
>   }
>   
> -static bool vfio_interrupt_setup(VFIOPCIDevice *vdev, Error **errp)
> +bool vfio_pci_interrupt_setup(VFIOPCIDevice *vdev, Error **errp)
>   {
>       PCIDevice *pdev = &vdev->pdev;
>   
> @@ -3214,7 +3214,7 @@ static void vfio_pci_realize(PCIDevice *pdev, Error **errp)
>           goto error;
>       }
>   
> -    if (!vfio_populate_device(vdev, errp)) {
> +    if (!vfio_pci_populate_device(vdev, errp)) {
>           goto error;
>       }
>   
> @@ -3228,7 +3228,7 @@ static void vfio_pci_realize(PCIDevice *pdev, Error **errp)
>           goto out_teardown;
>       }
>   
> -    if (!vfio_add_capabilities(vdev, errp)) {
> +    if (!vfio_pci_add_capabilities(vdev, errp)) {
>           goto out_unset_idev;
>       }
>   
> @@ -3244,7 +3244,7 @@ static void vfio_pci_realize(PCIDevice *pdev, Error **errp)
>           vfio_bar_quirk_setup(vdev, i);
>       }
>   
> -    if (!vfio_interrupt_setup(vdev, errp)) {
> +    if (!vfio_pci_interrupt_setup(vdev, errp)) {
>           goto out_unset_idev;
>       }
>   
> @@ -3288,8 +3288,8 @@ static void vfio_pci_realize(PCIDevice *pdev, Error **errp)
>           }
>       }
>   
> -    vfio_register_err_notifier(vdev);
> -    vfio_register_req_notifier(vdev);
> +    vfio_pci_register_err_notifier(vdev);
> +    vfio_pci_register_req_notifier(vdev);
>       vfio_setup_resetfn_quirk(vdev);
>   
>       return;
> @@ -3310,8 +3310,8 @@ out_unset_idev:
>           pci_device_unset_iommu_device(pdev);
>       }
>   out_teardown:
> -    vfio_teardown_msi(vdev);
> -    vfio_bars_exit(vdev);
> +    vfio_pci_teardown_msi(vdev);
> +    vfio_pci_bars_exit(vdev);
>   error:
>       error_prepend(errp, VFIO_MSG_PREFIX, vbasedev->name);
>   }
> @@ -3338,9 +3338,9 @@ static void vfio_exitfn(PCIDevice *pdev)
>       if (vdev->intx.mmap_timer) {
>           timer_free(vdev->intx.mmap_timer);
>       }
> -    vfio_teardown_msi(vdev);
> +    vfio_pci_teardown_msi(vdev);
>       vfio_pci_disable_rp_atomics(vdev);
> -    vfio_bars_exit(vdev);
> +    vfio_pci_bars_exit(vdev);
>       vfio_migration_exit(vbasedev);
>       if (!vbasedev->mdev) {
>           pci_device_unset_iommu_device(pdev);
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index e90ec9bff8..f06236f37b 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -2,7 +2,7 @@
>   
>   # pci.c
>   vfio_intx_interrupt(const char *name, char line) " (%s) Pin %c"
> -vfio_intx_eoi(const char *name) " (%s) EOI"
> +vfio_pci_intx_eoi(const char *name) " (%s) EOI"
>   vfio_intx_enable_kvm(const char *name) " (%s) KVM INTx accel enabled"
>   vfio_intx_disable_kvm(const char *name) " (%s) KVM INTx accel disabled"
>   vfio_intx_update(const char *name, int new_irq, int target_irq) " (%s) IRQ moved %d -> %d"
> @@ -35,8 +35,8 @@ vfio_pci_hot_reset(const char *name, const char *type) " (%s) %s"
>   vfio_pci_hot_reset_has_dep_devices(const char *name) "%s: hot reset dependent devices:"
>   vfio_pci_hot_reset_dep_devices(int domain, int bus, int slot, int function, int group_id) "\t%04x:%02x:%02x.%x group %d"
>   vfio_pci_hot_reset_result(const char *name, const char *result) "%s hot reset: %s"
> -vfio_populate_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device '%s' config: size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
> -vfio_populate_device_get_irq_info_failure(const char *errstr) "VFIO_DEVICE_GET_IRQ_INFO failure: %s"
> +vfio_pci_populate_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device '%s' config: size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
> +vfio_pci_populate_device_get_irq_info_failure(const char *errstr) "VFIO_DEVICE_GET_IRQ_INFO failure: %s"
>   vfio_mdev(const char *name, bool is_mdev) " (%s) is_mdev %d"
>   vfio_add_ext_cap_dropped(const char *name, uint16_t cap, uint16_t offset) "%s 0x%x@0x%x"
>   vfio_pci_reset(const char *name) " (%s)"