PCI/MSI: Size device MSI domain with the maximum number of vectors

Zenghui reports that since 1396e89e09 ("genirq/msi: Move prepare() call
to per-device allocation"), his Multi-MSI capable device isn't working
anymore.

This is a consequence of 15c72f824b ("PCI/MSI: Add support for per device
MSI[X] domains"), which always creates a MSI domain of size 1, even in the
presence of Multi-MSI.

While this was somehow working until then, moving the .prepare() call ends
up sizing the ITS table with a tiny value for this device, and making the
endpoint driver unhappy.

Instead, always create the domain and call the .prepare() helper with the
maximum expected size.

Fixes: 1396e89e09 ("genirq/msi: Move prepare() call to per-device allocation")
Fixes: 15c72f824b ("PCI/MSI: Add support for per device MSI[X] domains")
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Link: https://lore.kernel.org/all/20250603141801.915305-1-maz@kernel.org
Closes: https://lore.kernel.org/r/0b1d7aec-1eac-a9cd-502a-339e216e08a1@huawei.com
This commit is contained in:
Marc Zyngier 2025-06-03 15:18:01 +01:00 committed by Thomas Gleixner
parent 5abc7438f1
commit 9cc82d99b1
3 changed files with 8 additions and 7 deletions

View file

@ -271,6 +271,7 @@ static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_doma
/**
* pci_setup_msi_device_domain - Setup a device MSI interrupt domain
* @pdev: The PCI device to create the domain on
* @hwsize: The maximum number of MSI vectors
*
* Return:
* True when:
@ -287,7 +288,7 @@ 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 +298,7 @@ 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);
}
/**

View file

@ -439,16 +439,16 @@ int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
if (nvec < minvec)
return -ENOSPC;
if (nvec > maxvec)
nvec = maxvec;
rc = pci_setup_msi_context(dev);
if (rc)
return rc;
if (!pci_setup_msi_device_domain(dev))
if (!pci_setup_msi_device_domain(dev, nvec))
return -ENODEV;
if (nvec > maxvec)
nvec = maxvec;
for (;;) {
if (affd) {
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);

View file

@ -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 */