linux-kernel - linux-next: NVME using PCI legacy interrupts only

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 9 Jun 2021 20:43:57 +0200
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Marc Zyngier <maz@...nel.org>, Thomas Gleixner <tglx@...utronix.de>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "linux-nvme@...ts.infradead.org" <linux-nvme@...ts.infradead.org>,
        Christoph Hellwig <hch@....de>
Subject: linux-next: NVME using PCI legacy interrupts only

I found that on linux-next from June 8th my nvme disk is using legacy
interrupts only. Some debugging lead me to irq_find_mapping() in
msi_domain_alloc() returning -EEXIST.

The nvme core first allocates a MSI-X interrupt for setup purposes
and later frees it and allocates the final number of MSI-X interrupts.

The following experimental change brought back the MSI-X interrupts.
This makes me think that somehow freeing a MSI-X interrupt doesn't
free it completely. I didn't see this behavior a few days ago,
therefore I think it's related to the recent changes to
irqdomain/genirq.

Didn't do a bisect yet, maybe you have an idea already.

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index a29b17070..8cc600819 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2381,7 +2381,7 @@ static int nvme_pci_enable(struct nvme_dev *dev)
         * interrupts. Pre-enable a single MSIX or MSI vec for setup. We'll
         * adjust this later.
         */
-       result = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
+       result = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_LEGACY);
        if (result < 0)
                return result;