linux-kernel - [RFC PATCH v1 3/8] iommu/arm-smmu-v3-sva: Allocate new ASID from installed

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: <20230818021629.RFC.v1.3.I326c62dc062aed8d901d319aa665dbe983c7904c@changeid>
Date:   Fri, 18 Aug 2023 02:16:25 +0800
From:   Michael Shavit <mshavit@...gle.com>
To:     iommu@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Cc:     will@...nel.org, jgg@...dia.com, nicolinc@...dia.com,
        tina.zhang@...el.com, jean-philippe@...aro.org,
        robin.murphy@....com, Michael Shavit <mshavit@...gle.com>
Subject: [RFC PATCH v1 3/8] iommu/arm-smmu-v3-sva: Allocate new ASID from installed_smmus

Pick an ASID that is within the supported range of all SMMUs that the
domain is installed to.

Signed-off-by: Michael Shavit <mshavit@...gle.com>
---

 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 23 +++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 58def59c36004..ab941e394cae5 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -82,6 +82,20 @@ static int arm_smmu_write_ctx_desc_devices(struct arm_smmu_domain *smmu_domain,
 	return ret;
 }
 
+static u32 arm_smmu_domain_max_asid_bits(struct arm_smmu_domain *smmu_domain)
+{
+	struct arm_smmu_installed_smmu *installed_smmu;
+	unsigned long flags;
+	u32 asid_bits = 16;
+
+	spin_lock_irqsave(&smmu_domain->installed_smmus_lock, flags);
+	list_for_each_entry(installed_smmu, &smmu_domain->installed_smmus,
+			    list)
+		asid_bits = min(asid_bits, installed_smmu->smmu->asid_bits);
+	spin_unlock_irqrestore(&smmu_domain->installed_smmus_lock, flags);
+	return asid_bits;
+}
+
 /*
  * Check if the CPU ASID is available on the SMMU side. If a private context
  * descriptor is using it, try to replace it.
@@ -92,7 +106,6 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid)
 	int ret;
 	u32 new_asid;
 	struct arm_smmu_ctx_desc *cd;
-	struct arm_smmu_device *smmu;
 	struct arm_smmu_domain *smmu_domain;
 
 	cd = xa_load(&arm_smmu_asid_xa, asid);
@@ -108,10 +121,12 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid)
 	}
 
 	smmu_domain = container_of(cd, struct arm_smmu_domain, cd);
-	smmu = smmu_domain->smmu;
 
-	ret = xa_alloc(&arm_smmu_asid_xa, &new_asid, cd,
-		       XA_LIMIT(1, (1 << smmu->asid_bits) - 1), GFP_KERNEL);
+	ret = xa_alloc(
+		&arm_smmu_asid_xa, &new_asid, cd,
+		XA_LIMIT(1,
+			 (1 << arm_smmu_domain_max_asid_bits(smmu_domain)) - 1),
+		GFP_KERNEL);
 	if (ret)
 		return ERR_PTR(-ENOSPC);
 	/*
-- 
2.42.0.rc1.204.g551eb34607-goog