linux-kernel - [PATCH v2 2/5] bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR

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: <20250710-sriov_vdev_next-20250630-v2-2-4bd862b822e8@quicinc.com>
Date: Thu, 10 Jul 2025 14:28:33 +0530
From: Vivek.Pernamitta@...cinc.com
To: Manivannan Sadhasivam <mani@...nel.org>
CC: <mhi@...ts.linux.dev>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        Vivek Pernamitta <quic_vpernami@...cinc.com>,
        Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
Subject: [PATCH v2 2/5] bus: mhi: host: pci_generic: Read
 SUBSYSTEM_VENDOR_ID for VF's to check status

From: Vivek Pernamitta <quic_vpernami@...cinc.com>

In SRIOV enabled devices, the VF DEVICE/VENDOR ID register returns FFFFh
when read (PCIe SRIOV spec-3.4.1.1). Therefore, read the PCIe
SUBSYSTEM_VENDOR_ID to check if the device is active.

Signed-off-by: Vivek Pernamitta <quic_vpernami@...cinc.com>
Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
---
 drivers/bus/mhi/host/pci_generic.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
index 7d0ac1c34ddf95ace2a85e5f08884f51604d9b0f..4bafe93b56c54e2b091786e7fcd68a36c8247b8e 100644
--- a/drivers/bus/mhi/host/pci_generic.c
+++ b/drivers/bus/mhi/host/pci_generic.c
@@ -1025,8 +1025,10 @@ static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl)
 	struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
 	u16 vendor = 0;
 
-	if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
-		return false;
+	if (pdev->is_virtfn)
+		pci_read_config_word(pdev, PCI_SUBSYSTEM_VENDOR_ID, &vendor);
+	else
+		pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor);
 
 	if (vendor == (u16) ~0 || vendor == 0)
 		return false;

-- 
2.34.1