From: Nicolin Chen <nicolinc@nvidia.com>
To: <jgg@nvidia.com>, <kevin.tian@intel.com>, <corbet@lwn.net>,
<will@kernel.org>
Cc: <joro@8bytes.org>, <suravee.suthikulpanit@amd.com>,
<robin.murphy@arm.com>, <dwmw2@infradead.org>,
<baolu.lu@linux.intel.com>, <shuah@kernel.org>,
<linux-kernel@vger.kernel.org>, <iommu@lists.linux.dev>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kselftest@vger.kernel.org>, <linux-doc@vger.kernel.org>,
<eric.auger@redhat.com>, <jean-philippe@linaro.org>,
<mdf@kernel.org>, <mshavit@google.com>,
<shameerali.kolothum.thodi@huawei.com>, <smostafa@google.com>,
<ddutile@redhat.com>, <yi.l.liu@intel.com>,
<patches@lists.linux.dev>
Subject: [PATCH v6 14/14] iommu/arm-smmu-v3: Set MEV bit in nested STE for DoS mitigations
Date: Fri, 24 Jan 2025 16:30:43 -0800 [thread overview]
Message-ID: <436ac2021bb3d75114ca0e45f25a6a8257489d3b.1737754129.git.nicolinc@nvidia.com> (raw)
In-Reply-To: <cover.1737754129.git.nicolinc@nvidia.com>
There is a DoS concern on the shared hardware event queue among devices
passed through to VMs, that too many translation failures that belong to
VMs could overflow the shared hardware event queue if those VMs or their
VMMs don't handle/recover the devices properly.
The MEV bit in the STE allows to configure the SMMU HW to merge similar
event records, though there is no guarantee. Set it in a nested STE for
DoS mitigations.
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 +
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 2 ++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 ++--
3 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index d24c3d8ee397..7181001fc5d7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -266,6 +266,7 @@ static inline u32 arm_smmu_strtab_l2_idx(u32 sid)
#define STRTAB_STE_1_S1COR GENMASK_ULL(5, 4)
#define STRTAB_STE_1_S1CSH GENMASK_ULL(7, 6)
+#define STRTAB_STE_1_MEV (1UL << 19)
#define STRTAB_STE_1_S2FWB (1UL << 25)
#define STRTAB_STE_1_S1STALLD (1UL << 27)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
index ceeed907a714..20a0e39d7caa 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
@@ -43,6 +43,8 @@ static void arm_smmu_make_nested_cd_table_ste(
target->data[0] |= nested_domain->ste[0] &
~cpu_to_le64(STRTAB_STE_0_CFG);
target->data[1] |= nested_domain->ste[1];
+ /* Merge events for DoS mitigations on eventq */
+ target->data[1] |= STRTAB_STE_1_MEV;
}
/*
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 59fbc342a095..14e079cfb8b6 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1051,7 +1051,7 @@ void arm_smmu_get_ste_used(const __le64 *ent, __le64 *used_bits)
cpu_to_le64(STRTAB_STE_1_S1DSS | STRTAB_STE_1_S1CIR |
STRTAB_STE_1_S1COR | STRTAB_STE_1_S1CSH |
STRTAB_STE_1_S1STALLD | STRTAB_STE_1_STRW |
- STRTAB_STE_1_EATS);
+ STRTAB_STE_1_EATS | STRTAB_STE_1_MEV);
used_bits[2] |= cpu_to_le64(STRTAB_STE_2_S2VMID);
/*
@@ -1067,7 +1067,7 @@ void arm_smmu_get_ste_used(const __le64 *ent, __le64 *used_bits)
if (cfg & BIT(1)) {
used_bits[1] |=
cpu_to_le64(STRTAB_STE_1_S2FWB | STRTAB_STE_1_EATS |
- STRTAB_STE_1_SHCFG);
+ STRTAB_STE_1_SHCFG | STRTAB_STE_1_MEV);
used_bits[2] |=
cpu_to_le64(STRTAB_STE_2_S2VMID | STRTAB_STE_2_VTCR |
STRTAB_STE_2_S2AA64 | STRTAB_STE_2_S2ENDI |
--
2.43.0
next prev parent reply other threads:[~2025-01-25 0:31 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-25 0:30 [PATCH v6 00/14] iommufd: Add vIOMMU infrastructure (Part-3: vEVENTQ) Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 01/14] iommufd/fault: Move two fault functions out of the header Nicolin Chen
2025-02-14 20:15 ` Jason Gunthorpe
2025-02-18 5:05 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 02/14] iommufd/fault: Add an iommufd_fault_init() helper Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 03/14] iommufd: Abstract an iommufd_eventq from iommufd_fault Nicolin Chen
2025-02-14 20:23 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 04/14] iommufd: Rename fault.c to eventq.c Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 05/14] iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC Nicolin Chen
2025-02-18 5:13 ` Tian, Kevin
2025-02-18 17:53 ` Nicolin Chen
2025-02-18 15:29 ` Jason Gunthorpe
2025-02-18 17:47 ` Nicolin Chen
2025-02-18 18:08 ` Jason Gunthorpe
2025-02-18 18:15 ` Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 06/14] iommufd/viommu: Add iommufd_viommu_get_vdev_id helper Nicolin Chen
2025-02-18 15:31 ` Jason Gunthorpe
2025-02-20 5:17 ` Nicolin Chen
2025-02-20 16:19 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 07/14] iommufd/viommu: Add iommufd_viommu_report_event helper Nicolin Chen
2025-02-18 5:14 ` Tian, Kevin
2025-02-18 15:35 ` Jason Gunthorpe
2025-02-19 6:58 ` Tian, Kevin
2025-02-20 21:16 ` Nicolin Chen
2025-02-21 4:27 ` Tian, Kevin
2025-02-21 13:39 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 08/14] iommufd/selftest: Require vdev_id when attaching to a nested domain Nicolin Chen
2025-02-18 5:15 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 09/14] iommufd/selftest: Add IOMMU_TEST_OP_TRIGGER_VEVENT for vEVENTQ coverage Nicolin Chen
2025-02-18 5:16 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 10/14] iommufd/selftest: Add IOMMU_VEVENTQ_ALLOC test coverage Nicolin Chen
2025-02-18 5:19 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 11/14] Documentation: userspace-api: iommufd: Update FAULT and VEVENTQ Nicolin Chen
2025-01-28 8:21 ` Bagas Sanjaya
2025-02-18 17:02 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 12/14] iommu/arm-smmu-v3: Introduce struct arm_smmu_vmaster Nicolin Chen
2025-02-18 17:08 ` Jason Gunthorpe
2025-02-20 7:16 ` Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 13/14] iommu/arm-smmu-v3: Report events that belong to devices attached to vIOMMU Nicolin Chen
2025-02-18 5:21 ` Tian, Kevin
2025-02-18 17:18 ` Jason Gunthorpe
2025-02-18 18:28 ` Nicolin Chen
2025-02-18 18:50 ` Jason Gunthorpe
2025-02-18 19:02 ` Nicolin Chen
2025-02-18 19:08 ` Jason Gunthorpe
2025-02-18 19:27 ` Nicolin Chen
2025-02-20 20:45 ` Nicolin Chen
2025-02-20 23:24 ` Jason Gunthorpe
2025-02-21 8:10 ` Nicolin Chen
2025-01-25 0:30 ` Nicolin Chen [this message]
2025-02-18 5:24 ` [PATCH v6 14/14] iommu/arm-smmu-v3: Set MEV bit in nested STE for DoS mitigations Tian, Kevin
2025-02-18 18:17 ` Pranjal Shrivastava
2025-02-18 18:52 ` Jason Gunthorpe
2025-02-20 7:12 ` Nicolin Chen
2025-02-18 18:53 ` Nicolin Chen
2025-02-20 16:15 ` Pranjal Shrivastava
2025-02-18 17:21 ` Jason Gunthorpe
2025-02-18 18:14 ` Nicolin Chen
2025-02-20 9:09 ` Nicolin Chen
2025-02-14 8:03 ` [PATCH v6 00/14] iommufd: Add vIOMMU infrastructure (Part-3: vEVENTQ) Nicolin Chen
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