linux-kernel - [PATCH AUTOSEL 6.1 049/212] vfio/pci: Handle INTx IRQ

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

Message-Id: <20250505230624.2692522-49-sashal@kernel.org>
Date: Mon,  5 May 2025 19:03:41 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Alex Williamson <alex.williamson@...hat.com>,
	Kevin Tian <kevin.tian@...el.com>,
	Sasha Levin <sashal@...nel.org>,
	Yunxiang.Li@....com,
	avihaih@...dia.com,
	yi.l.liu@...el.com,
	zhangdongdong@...incomputing.com,
	jgg@...pe.ca,
	bhelgaas@...gle.com,
	peterx@...hat.com,
	pstanner@...hat.com,
	dan.carpenter@...aro.org,
	pabeni@...hat.com,
	kvm@...r.kernel.org
Subject: [PATCH AUTOSEL 6.1 049/212] vfio/pci: Handle INTx IRQ_NOTCONNECTED

From: Alex Williamson <alex.williamson@...hat.com>

[ Upstream commit 860be250fc32de9cb24154bf21b4e36f40925707 ]

Some systems report INTx as not routed by setting pdev->irq to
IRQ_NOTCONNECTED, resulting in a -ENOTCONN error when trying to
setup eventfd signaling.  Include this in the set of conditions
for which the PIN register is virtualized to zero.

Additionally consolidate vfio_pci_get_irq_count() to use this
virtualized value in reporting INTx support via ioctl and sanity
checking ioctl paths since pdev->irq is re-used when the device
is in MSI mode.

The combination of these results in both the config space of the
device and the ioctl interface behaving as if the device does not
support INTx.

Reviewed-by: Kevin Tian <kevin.tian@...el.com>
Link: https://lore.kernel.org/r/20250311230623.1264283-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/vfio/pci/vfio_pci_config.c |  3 ++-
 drivers/vfio/pci/vfio_pci_core.c   | 10 +---------
 drivers/vfio/pci/vfio_pci_intrs.c  |  2 +-
 3 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 7902e1ec0fef2..105243d83b2dc 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -1806,7 +1806,8 @@ int vfio_config_init(struct vfio_pci_core_device *vdev)
 					cpu_to_le16(PCI_COMMAND_MEMORY);
 	}
 
-	if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx)
+	if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx ||
+	    vdev->pdev->irq == IRQ_NOTCONNECTED)
 		vconfig[PCI_INTERRUPT_PIN] = 0;
 
 	ret = vfio_cap_init(vdev);
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index f357fd157e1ed..aa362b434413a 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -719,15 +719,7 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_finish_enable);
 static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_type)
 {
 	if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
-		u8 pin;
-
-		if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) ||
-		    vdev->nointx || vdev->pdev->is_virtfn)
-			return 0;
-
-		pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
-
-		return pin ? 1 : 0;
+		return vdev->vconfig[PCI_INTERRUPT_PIN] ? 1 : 0;
 	} else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
 		u8 pos;
 		u16 flags;
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 5cbcde32ff79e..64d78944efa53 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -207,7 +207,7 @@ static int vfio_intx_enable(struct vfio_pci_core_device *vdev,
 	if (!is_irq_none(vdev))
 		return -EINVAL;
 
-	if (!pdev->irq)
+	if (!pdev->irq || pdev->irq == IRQ_NOTCONNECTED)
 		return -ENODEV;
 
 	name = kasprintf(GFP_KERNEL_ACCOUNT, "vfio-intx(%s)", pci_name(pdev));
-- 
2.39.5