From: Keith Busch <keith.busch@intel.com>
Date: Thu, 20 Jul 2017 19:33:54 -0400
Subject: PCI: vmd: Assign vector zero to all bridges
Git-commit: f2586c678cb29f40a37c9c88a22b13d35484ffdc
Patch-mainline: v4.14-rc1
References: bsc#1109806

We don't want slower IRQ handlers impacting faster devices that happen to
be assigned the same VMD interrupt vector. The driver was trying to
separate such devices by checking if MSI-X wasn't used, but really we just
don't want endpoint devices to share with bridges. Most bridges may use MSI
currently, so that criteria happened to work, but newer ones may use MSI-X,
so this patch explicitly checks the device type when choosing a vector.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/host/vmd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/host/vmd.c b/drivers/pci/host/vmd.c
index 539da102f3d7..7e967a8784b2 100644
--- a/drivers/pci/host/vmd.c
+++ b/drivers/pci/host/vmd.c
@@ -183,7 +183,7 @@ static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *d
 	int i, best = 1;
 	unsigned long flags;
 
-	if (!desc->msi_attrib.is_msix || vmd->msix_count == 1)
+	if (pci_is_bridge(msi_desc_to_pci_dev(desc)) || vmd->msix_count == 1)
 		return &vmd->irqs[0];
 
 	raw_spin_lock_irqsave(&list_lock, flags);