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AJvYcCVDTSBfiK1eL1c9YzM17nnIq7cTEDHkO3ytXAtfaVX29g22Z+FqBvjlrAg8QmHqhfoeX92KjYM6HdELD2I=@vger.kernel.org X-Gm-Message-State: AOJu0Yz7pTRLIg7022F2m01G8L4cEMojbijpe+5LM7ethDn/0DZi8oRc fLljZUW6CGGfuEM+I0+K/fHvA51+/oQIfcni4RFAayJ5PJzFgXcHEGq/DJdQWzu2AUri0ligWZy jOi9GVcU7ncIyJg== X-Google-Smtp-Source: AGHT+IHvvN75ZRrmEK6mbR78xTnUzHtBzNs3L5jIM2mnz88x+TZ3qPg9z7gWLJIqDbGhhpJDNO5GQC2qpVQ4ZQ== X-Received: from wmgg23.prod.google.com ([2002:a05:600d:17:b0:477:7aa2:99cb]) (user=smostafa job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:4452:b0:477:8b2e:aa8f with SMTP id 5b1f17b1804b1-4778fe6a42fmr114864735e9.15.1763405326933; Mon, 17 Nov 2025 10:48:46 -0800 (PST) Date: Mon, 17 Nov 2025 18:48:08 +0000 In-Reply-To: <20251117184815.1027271-1-smostafa@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251117184815.1027271-1-smostafa@google.com> X-Mailer: git-send-email 2.52.0.rc1.455.g30608eb744-goog Message-ID: <20251117184815.1027271-22-smostafa@google.com> Subject: [PATCH v5 21/27] iommu/arm-smmu-v3-kvm: Emulate CMDQ for host From: Mostafa Saleh To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, iommu@lists.linux.dev Cc: catalin.marinas@arm.com, will@kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, joro@8bytes.org, jean-philippe@linaro.org, jgg@ziepe.ca, praan@google.com, danielmentz@google.com, mark.rutland@arm.com, qperret@google.com, tabba@google.com, Mostafa Saleh Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Don=E2=80=99t allow access to the command queue from the host: - ARM_SMMU_CMDQ_BASE: Only allowed to be written when CMDQ is disabled, we use it to keep track of the host command queue base. Reads return the saved value. - ARM_SMMU_CMDQ_PROD: Writes trigger command queue emulation which sanitise and filters the whole range. Reads returns the host copy. - ARM_SMMU_CMDQ_CONS: Writes move the sw copy of the cons, but the host can= =E2=80=99t skip commands once submitted. Reads return the emulated value and the err= or bits in the actual cons. Signed-off-by: Mostafa Saleh --- .../iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c | 119 +++++++++++++++++- 1 file changed, 115 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c b/drivers/iom= mu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c index a970b43e6a7e..746ffc4b0a70 100644 --- a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c @@ -60,6 +60,16 @@ static void smmu_reclaim_pages(u64 phys, size_t size) WARN_ON(__pkvm_hyp_donate_host(phys >> PAGE_SHIFT, size >> PAGE_SHIFT)); } =20 +static void smmu_copy_from_host(struct hyp_arm_smmu_v3_device *smmu, + void *dst_hyp_va, void *src_hyp_va, + size_t size) +{ + /* Clean and inval DC as the kernel uses NC mapping. */ + if (!(smmu->features & ARM_SMMU_FEAT_COHERENCY)) + kvm_flush_dcache_to_poc(src_hyp_va, size); + memcpy(dst_hyp_va, src_hyp_va, size); +} + /* * CMDQ, STE host copies are accessed by the hypervisor, we share them to * - Prevent the host from passing protected VM memory. @@ -89,7 +99,6 @@ static int smmu_unshare_pages(phys_addr_t addr, size_t si= ze) return 0; } =20 -__maybe_unused static bool smmu_cmdq_has_space(struct arm_smmu_queue *cmdq, u32 n) { struct arm_smmu_ll_queue *llq =3D &cmdq->llq; @@ -327,6 +336,88 @@ static int smmu_init(void) return ret; } =20 +static bool smmu_filter_command(struct hyp_arm_smmu_v3_device *smmu, u64 *= command) +{ + u64 type =3D FIELD_GET(CMDQ_0_OP, command[0]); + + switch (type) { + case CMDQ_OP_CFGI_STE: + /* TBD: SHADOW_STE*/ + break; + case CMDQ_OP_CFGI_ALL: + { + /* + * Linux doesn't use range STE invalidation, and only use this + * for CFGI_ALL, which is done on reset and not on an new STE + * being used. + * Although, this is not architectural we rely on the current Linux + * implementation. + */ + WARN_ON((FIELD_GET(CMDQ_CFGI_1_RANGE, command[1]) !=3D 31)); + break; + } + case CMDQ_OP_TLBI_NH_ASID: + case CMDQ_OP_TLBI_NH_VA: + case 0x13: /* CMD_TLBI_NH_VAA: Not used by Linux */ + { + /* Only allow VMID =3D 0*/ + if (FIELD_GET(CMDQ_TLBI_0_VMID, command[0]) =3D=3D 0) + break; + break; + } + case 0x10: /* CMD_TLBI_NH_ALL: Not used by Linux */ + case CMDQ_OP_TLBI_EL2_ALL: + case CMDQ_OP_TLBI_EL2_VA: + case CMDQ_OP_TLBI_EL2_ASID: + case CMDQ_OP_TLBI_S12_VMALL: + case 0x23: /* CMD_TLBI_EL2_VAA: Not used by Linux */ + return WARN_ON(true); + case CMDQ_OP_CMD_SYNC: + if (FIELD_GET(CMDQ_SYNC_0_CS, command[0]) =3D=3D CMDQ_SYNC_0_CS_IRQ) { + /* Allow it, but let the host timeout, as this should never happen. */ + command[0] &=3D ~CMDQ_SYNC_0_CS; + command[0] |=3D FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV); + command[1] &=3D ~CMDQ_SYNC_1_MSIADDR_MASK; + } + break; + } + + return false; +} + +static void smmu_emulate_cmdq_insert(struct hyp_arm_smmu_v3_device *smmu) +{ + u64 *host_cmdq =3D hyp_phys_to_virt(smmu->cmdq_host.q_base & Q_BASE_ADDR_= MASK); + int idx; + u64 cmd[CMDQ_ENT_DWORDS]; + bool skip; + u32 space; + bool use_wfe =3D smmu->features & ARM_SMMU_FEAT_SEV; + + if (!is_cmdq_enabled(smmu)) + return; + + space =3D (1 << (smmu->cmdq_host.llq.max_n_shift)) - queue_space(&smmu->c= mdq_host.llq); + /* Wait for the command queue to have some space. */ + WARN_ON(smmu_wait(use_wfe, smmu_cmdq_has_space(&smmu->cmdq, space))); + + while (space--) { + idx =3D Q_IDX(&smmu->cmdq_host.llq, smmu->cmdq_host.llq.cons); + queue_inc_cons(&smmu->cmdq_host.llq); + + smmu_copy_from_host(smmu, cmd, &host_cmdq[idx * CMDQ_ENT_DWORDS], + CMDQ_ENT_DWORDS << 3); + skip =3D smmu_filter_command(smmu, cmd); + if (skip) + continue; + smmu_add_cmd_raw(smmu, cmd); + } + + writel_relaxed(smmu->cmdq.llq.prod, smmu->cmdq.prod_reg); + + WARN_ON(smmu_wait(use_wfe, smmu_cmdq_empty(&smmu->cmdq))); +} + static void smmu_emulate_cmdq_enable(struct hyp_arm_smmu_v3_device *smmu) { smmu->cmdq_host.llq.max_n_shift =3D smmu->cmdq_host.q_base & Q_BASE_LOG2S= IZE; @@ -360,17 +451,37 @@ static bool smmu_dabt_device(struct hyp_arm_smmu_v3_d= evice *smmu, mask =3D read_only & ~(IDR0_S2P | IDR0_VMID16 | IDR0_MSI | IDR0_HYP); WARN_ON(len !=3D sizeof(u32)); break; - /* Passthrough the register access for bisectiblity, handled later */ case ARM_SMMU_CMDQ_BASE: if (is_write) { /* Not allowed by the architecture */ WARN_ON(is_cmdq_enabled(smmu)); smmu->cmdq_host.q_base =3D val; + } else { + regs->regs[rd] =3D smmu->cmdq_host.q_base; } - mask =3D read_write; - break; + goto out_ret; case ARM_SMMU_CMDQ_PROD: + if (is_write) { + smmu->cmdq_host.llq.prod =3D val; + smmu_emulate_cmdq_insert(smmu); + } else { + regs->regs[rd] =3D smmu->cmdq_host.llq.prod; + } + goto out_ret; case ARM_SMMU_CMDQ_CONS: + if (is_write) { + /* Not allowed by the architecture */ + WARN_ON(is_cmdq_enabled(smmu)); + smmu->cmdq_host.llq.cons =3D val; + } else { + /* Propagate errors back to the host.*/ + u32 cons =3D readl_relaxed(smmu->base + ARM_SMMU_CMDQ_CONS); + u32 err =3D CMDQ_CONS_ERR & cons; + + regs->regs[rd] =3D smmu->cmdq_host.llq.cons | err; + } + goto out_ret; + /* Passthrough the register access for bisectiblity, handled later */ case ARM_SMMU_STRTAB_BASE: case ARM_SMMU_STRTAB_BASE_CFG: case ARM_SMMU_GBPA: --=20 2.52.0.rc1.455.g30608eb744-goog