linux-kernel - [PATCH v2 3/5] vfio/iommu_type1: Remove the domain->ops comparison

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]

Date:   Wed, 15 Jun 2022 17:03:02 -0700
From:   Nicolin Chen <nicolinc@...dia.com>
To:     <joro@...tes.org>, <will@...nel.org>, <marcan@...can.st>,
        <sven@...npeter.dev>, <robin.murphy@....com>,
        <robdclark@...il.com>, <baolu.lu@...ux.intel.com>,
        <matthias.bgg@...il.com>, <orsonzhai@...il.com>,
        <baolin.wang7@...il.com>, <zhang.lyra@...il.com>,
        <jean-philippe@...aro.org>, <alex.williamson@...hat.com>,
        <jgg@...dia.com>, <kevin.tian@...el.com>
CC:     <suravee.suthikulpanit@....com>, <alyssa@...enzweig.io>,
        <dwmw2@...radead.org>, <yong.wu@...iatek.com>,
        <mjrosato@...ux.ibm.com>, <gerald.schaefer@...ux.ibm.com>,
        <thierry.reding@...il.com>, <vdumpa@...dia.com>,
        <jonathanh@...dia.com>, <cohuck@...hat.com>,
        <thunder.leizhen@...wei.com>, <tglx@...utronix.de>,
        <christophe.jaillet@...adoo.fr>, <john.garry@...wei.com>,
        <chenxiang66@...ilicon.com>, <saiprakash.ranjan@...eaurora.org>,
        <isaacm@...eaurora.org>, <yangyingliang@...wei.com>,
        <jordan@...micpenguin.net>, <iommu@...ts.linux-foundation.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-arm-msm@...r.kernel.org>,
        <linux-mediatek@...ts.infradead.org>, <linux-s390@...r.kernel.org>,
        <linux-tegra@...r.kernel.org>,
        <virtualization@...ts.linux-foundation.org>, <kvm@...r.kernel.org>
Subject: [PATCH v2 3/5] vfio/iommu_type1: Remove the domain->ops comparison

The domain->ops validation was added, as a precaution, for mixed-driver
systems. However, at this moment only one iommu driver is possible. So
remove it.

Per discussion with Robin, in future when many can be permitted we will
rely on the IOMMU core code to check the domain->ops:
https://lore.kernel.org/linux-iommu/6575de6d-94ba-c427-5b1e-967750ddff23@arm.com/

Signed-off-by: Nicolin Chen <nicolinc@...dia.com>
---
 drivers/vfio/vfio_iommu_type1.c | 32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index f4e3b423a453..11be5f95580b 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2277,29 +2277,19 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 			domain->domain->ops->enforce_cache_coherency(
 				domain->domain);
 
-	/*
-	 * Try to match an existing compatible domain.  We don't want to
-	 * preclude an IOMMU driver supporting multiple bus_types and being
-	 * able to include different bus_types in the same IOMMU domain, so
-	 * we test whether the domains use the same iommu_ops rather than
-	 * testing if they're on the same bus_type.
-	 */
+	/* Try to match an existing compatible domain */
 	list_for_each_entry(d, &iommu->domain_list, next) {
-		if (d->domain->ops == domain->domain->ops) {
-			iommu_detach_group(domain->domain, group->iommu_group);
-			if (!iommu_attach_group(d->domain,
-						group->iommu_group)) {
-				list_add(&group->next, &d->group_list);
-				iommu_domain_free(domain->domain);
-				kfree(domain);
-				goto done;
-			}
-
-			ret = iommu_attach_group(domain->domain,
-						 group->iommu_group);
-			if (ret)
-				goto out_domain;
+		iommu_detach_group(domain->domain, group->iommu_group);
+		if (!iommu_attach_group(d->domain, group->iommu_group)) {
+			list_add(&group->next, &d->group_list);
+			iommu_domain_free(domain->domain);
+			kfree(domain);
+			goto done;
 		}
+
+		ret = iommu_attach_group(domain->domain,  group->iommu_group);
+		if (ret)
+			goto out_domain;
 	}
 
 	vfio_test_domain_fgsp(domain);
-- 
2.17.1