From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 11 Nov 2022 13:55:11 +0000 (+0100)
Subject: PCI/MSI: Reject MSI-X early
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=99f3d279765725920aa5924fa445537a20129a6f;p=linux.git

PCI/MSI: Reject MSI-X early

Similar to PCI multi-MSI reject MSI-X enablement when a irq domain is
attached to the device which does not support MSI-X.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20221111122015.631728309@linutronix.de
---

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index bc84647c6dbd4..0740acd10bdef 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -762,6 +762,10 @@ int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int
 	if (WARN_ON_ONCE(dev->msix_enabled))
 		return -EINVAL;
 
+	/* Check MSI-X early on irq domain enabled architectures */
+	if (!pci_msi_domain_supports(dev, MSI_FLAG_PCI_MSIX, ALLOW_LEGACY))
+		return -ENOTSUPP;
+
 	if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
 		return -EINVAL;