[PATCH v2 3/5] genirq/msi: Move prepare() call to per-device allocation

[Marc Zyngier]

Hi Zenghui,

On Tue, 03 Jun 2025 09:22:47 +0100,
Zenghui Yu <yuzenghui at huawei.com> wrote:
> 
> > +	domain->dev = dev;
> > +	dev->msi.data->__domains[domid].domain = domain;
> > +
> > +	if (msi_domain_prepare_irqs(domain, dev, hwsize, &bundle->alloc_info)) {
> 
> Does it work for MSI? hwsize is 1 in the MSI case, without taking
> pci_msi_vec_count() into account.
>
> bool pci_setup_msi_device_domain(struct pci_dev *pdev)
> {
> 	[...]
> 
> 	return pci_create_device_domain(pdev, &pci_msi_template, 1);

Well spotted.

This looks like a PCI bug ignoring Multi-MSI. Can you give the
following a go and let people know whether that fixes your issue?

Thanks,

	M.

diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index d7ba8795d60f..89677a21d525 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -287,7 +287,7 @@ static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_doma
  *	- The device is removed
  *	- MSI is disabled and a MSI-X domain is created
  */
-bool pci_setup_msi_device_domain(struct pci_dev *pdev)
+bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize)
 {
 	if (WARN_ON_ONCE(pdev->msix_enabled))
 		return false;
@@ -297,7 +297,7 @@ bool pci_setup_msi_device_domain(struct pci_dev *pdev)
 	if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
 		msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
 
-	return pci_create_device_domain(pdev, &pci_msi_template, 1);
+	return pci_create_device_domain(pdev, &pci_msi_template, hwsize);
 }
 
 /**
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 8b8848788618..81891701840a 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -449,7 +449,7 @@ int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
 	if (rc)
 		return rc;
 
-	if (!pci_setup_msi_device_domain(dev))
+	if (!pci_setup_msi_device_domain(dev, nvec))
 		return -ENODEV;
 
 	for (;;) {
diff --git a/drivers/pci/msi/msi.h b/drivers/pci/msi/msi.h
index ee53cf079f4e..3ab898af88a7 100644
--- a/drivers/pci/msi/msi.h
+++ b/drivers/pci/msi/msi.h
@@ -107,7 +107,7 @@ enum support_mode {
 };
 
 bool pci_msi_domain_supports(struct pci_dev *dev, unsigned int feature_mask, enum support_mode mode);
-bool pci_setup_msi_device_domain(struct pci_dev *pdev);
+bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize);
 bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize);
 
 /* Legacy (!IRQDOMAIN) fallbacks */

-- 
Jazz isn't dead. It just smells funny.