linux-kernel - [PATCH v2 3/5] PCI/ATS: Skip VF ATS initialization if PF does not implement it

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: <21d93b3312418c1e28aeec238ef855c72efeb96a.1557162861.git.sathyanarayanan.kuppuswamy@linux.intel.com>
Date:   Mon,  6 May 2019 10:20:05 -0700
From:   sathyanarayanan.kuppuswamy@...ux.intel.com
To:     bhelgaas@...gle.com
Cc:     linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
        ashok.raj@...el.com, keith.busch@...el.com,
        sathyanarayanan.kuppuswamy@...ux.intel.com
Subject: [PATCH v2 3/5] PCI/ATS: Skip VF ATS initialization if PF does not implement it

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>

If PF does not implement ATS and VF implements/uses it, it might lead to
runtime issues. Also, as per spec r4.0, sec 9.3.7.8, PF should implement
ATS if VF implements it. So add additional check to confirm given device
aligns with the spec.

Cc: Ashok Raj <ashok.raj@...el.com>
Cc: Keith Busch <keith.busch@...el.com>
Suggested-by: Ashok Raj <ashok.raj@...el.com>
Reviewed-by: Keith Busch <keith.busch@...el.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
---
 drivers/pci/ats.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index e7a904e347c3..718e6f414680 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -19,6 +19,7 @@
 void pci_ats_init(struct pci_dev *dev)
 {
 	int pos;
+	struct pci_dev *pdev;
 
 	if (pci_ats_disabled())
 		return;
@@ -27,6 +28,17 @@ void pci_ats_init(struct pci_dev *dev)
 	if (!pos)
 		return;
 
+	/*
+	 * Per PCIe r4.0, sec 9.3.7.8, if VF implements Address Translation
+	 * Services (ATS) Extended Capability then corresponding PF should
+	 * also implement it.
+	 */
+	if (dev->is_virtfn) {
+		pdev = pci_physfn(dev);
+		if (!pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS))
+			return;
+	}
+
 	dev->ats_cap = pos;
 }
 
-- 
2.20.1