Re: [PATCH] PCI/MSI: Initialize the prepare descriptor by default

[Naman Jain]

On 7/8/2025 3:32 PM, Shradha Gupta wrote:

On Tue, Jul 08, 2025 at 10:48:48AM +0530, Naman Jain wrote:

Plug the default MSI-X prepare descriptor for non-implemented ops by
default to workaround the inability of Hyper-V vPCI module to setup
the MSI-X descriptors properly; especially for dynamically allocated
MSI-X.

Signed-off-by: Naman Jain <namj...@linux.microsoft.com>
---
  drivers/pci/msi/irqdomain.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index 765312c92d9b..655e99b9c8cc 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -84,6 +84,8 @@ static void pci_msi_domain_update_dom_ops(struct 
msi_domain_info *info)
        } else {
                if (ops->set_desc == NULL)
                        ops->set_desc = pci_msi_domain_set_desc;
+               if (ops->prepare_desc == NULL)
+                       ops->prepare_desc = pci_msix_prepare_desc;
        }
  }

base-commit: 26ffb3d6f02cd0935fb9fa3db897767beee1cb2a
--
2.34.1

Hey Naman,

can you please try your tests with this patch:
https://lore.kernel.org/all/1749651015-9668-1-git-send-email-shradhagu...@linux.microsoft.com/
I think this should help your use case

Regards,
Shradha.

Hey,
Thanks for sharing this, this works for me.

Closing this thread.

Regards,
Naman