Re: [PATCH v14 06/13] iommu/smmuv3: Allow stage 1 invalidation with unmanaged ASIDs
From: Auger Eric
Date: Thu Apr 08 2021 - 08:30:43 EST
Hi Kunkun,
On 4/1/21 2:37 PM, Kunkun Jiang wrote:
> Hi Eric,
>
> On 2021/2/24 4:56, Eric Auger wrote:
>> With nested stage support, soon we will need to invalidate
>> S1 contexts and ranges tagged with an unmanaged asid, this
>> latter being managed by the guest. So let's introduce 2 helpers
>> that allow to invalidate with externally managed ASIDs
>>
>> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>>
>> ---
>>
>> v13 -> v14
>> - Actually send the NH_ASID command (reported by Xingang Wang)
>> ---
>> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 38 ++++++++++++++++-----
>> 1 file changed, 29 insertions(+), 9 deletions(-)
>>
>> 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 5579ec4fccc8..4c19a1114de4 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> @@ -1843,9 +1843,9 @@ int arm_smmu_atc_inv_domain(struct
>> arm_smmu_domain *smmu_domain, int ssid,
>> }
>> /* IO_PGTABLE API */
>> -static void arm_smmu_tlb_inv_context(void *cookie)
>> +static void __arm_smmu_tlb_inv_context(struct arm_smmu_domain
>> *smmu_domain,
>> + int ext_asid)
>> {
>> - struct arm_smmu_domain *smmu_domain = cookie;
>> struct arm_smmu_device *smmu = smmu_domain->smmu;
>> struct arm_smmu_cmdq_ent cmd;
>> @@ -1856,7 +1856,13 @@ static void arm_smmu_tlb_inv_context(void
>> *cookie)
>> * insertion to guarantee those are observed before the TLBI. Do be
>> * careful, 007.
>> */
>> - if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>> + if (ext_asid >= 0) { /* guest stage 1 invalidation */
>> + cmd.opcode = CMDQ_OP_TLBI_NH_ASID;
>> + cmd.tlbi.asid = ext_asid;
>> + cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
>> + arm_smmu_cmdq_issue_cmd(smmu, &cmd);
>> + arm_smmu_cmdq_issue_sync(smmu);
>> + } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>> arm_smmu_tlb_inv_asid(smmu, smmu_domain->s1_cfg.cd.asid);
>> } else {
>> cmd.opcode = CMDQ_OP_TLBI_S12_VMALL;
>> @@ -1867,6 +1873,13 @@ static void arm_smmu_tlb_inv_context(void *cookie)
>> arm_smmu_atc_inv_domain(smmu_domain, 0, 0, 0);
>> }
>> +static void arm_smmu_tlb_inv_context(void *cookie)
>> +{
>> + struct arm_smmu_domain *smmu_domain = cookie;
>> +
>> + __arm_smmu_tlb_inv_context(smmu_domain, -1);
>> +}
>> +
>> static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
>> unsigned long iova, size_t size,
>> size_t granule,
>> @@ -1926,9 +1939,10 @@ static void __arm_smmu_tlb_inv_range(struct
>> arm_smmu_cmdq_ent *cmd,
>> arm_smmu_cmdq_batch_submit(smmu, &cmds);
>> }
>>
> Here is the part of code in __arm_smmu_tlb_inv_range():
>> if (smmu->features & ARM_SMMU_FEAT_RANGE_INV) {
>> /* Get the leaf page size */
>> tg = __ffs(smmu_domain->domain.pgsize_bitmap);
>>
>> /* Convert page size of 12,14,16 (log2) to 1,2,3 */
>> cmd->tlbi.tg = (tg - 10) / 2;
>>
>> /* Determine what level the granule is at */
>> cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));
>>
>> num_pages = size >> tg;
>> }
> When pSMMU supports RIL, we get the leaf page size by __ffs(smmu_domain->
> domain.pgsize_bitmap). In nested mode, it is determined by host
> PAGE_SIZE. If
> the host kernel and guest kernel has different translation granule (e.g.
> host 16K,
> guest 4K), __arm_smmu_tlb_inv_range() will issue an incorrect tlbi command.
>
> Do you have any idea about this issue?
I think this is the same issue as the one reported by Chenxiang
https://lore.kernel.org/lkml/15938ed5-2095-e903-a290-333c299015a2@xxxxxxxxxxxxx/
In case RIL is not supported by the host, next version will use the
smallest pSMMU supported page size, as done in __arm_smmu_tlb_inv_range
Thanks
Eric
>
> Best Regards,
> Kunkun Jiang
>> -static void arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t
>> size,
>> - size_t granule, bool leaf,
>> - struct arm_smmu_domain *smmu_domain)
>> +static void
>> +arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
>> + size_t granule, bool leaf, int ext_asid,
>> + struct arm_smmu_domain *smmu_domain)
>> {
>> struct arm_smmu_cmdq_ent cmd = {
>> .tlbi = {
>> @@ -1936,7 +1950,12 @@ static void
>> arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
>> },
>> };
>> - if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>> + if (ext_asid >= 0) { /* guest stage 1 invalidation */
>> + cmd.opcode = smmu_domain->smmu->features &
>> ARM_SMMU_FEAT_E2H ?
>> + CMDQ_OP_TLBI_EL2_VA : CMDQ_OP_TLBI_NH_VA;
>> + cmd.tlbi.asid = ext_asid;
>> + cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
>> + } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>> cmd.opcode = smmu_domain->smmu->features &
>> ARM_SMMU_FEAT_E2H ?
>> CMDQ_OP_TLBI_EL2_VA : CMDQ_OP_TLBI_NH_VA;
>> cmd.tlbi.asid = smmu_domain->s1_cfg.cd.asid;
>> @@ -1944,6 +1963,7 @@ static void
>> arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
>> cmd.opcode = CMDQ_OP_TLBI_S2_IPA;
>> cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
>> }
>> +
>> __arm_smmu_tlb_inv_range(&cmd, iova, size, granule, smmu_domain);
>> /*
>> @@ -1982,7 +2002,7 @@ static void arm_smmu_tlb_inv_page_nosync(struct
>> iommu_iotlb_gather *gather,
>> static void arm_smmu_tlb_inv_walk(unsigned long iova, size_t size,
>> size_t granule, void *cookie)
>> {
>> - arm_smmu_tlb_inv_range_domain(iova, size, granule, false, cookie);
>> + arm_smmu_tlb_inv_range_domain(iova, size, granule, false, -1,
>> cookie);
>> }
>> static const struct iommu_flush_ops arm_smmu_flush_ops = {
>> @@ -2523,7 +2543,7 @@ static void arm_smmu_iotlb_sync(struct
>> iommu_domain *domain,
>> arm_smmu_tlb_inv_range_domain(gather->start,
>> gather->end - gather->start + 1,
>> - gather->pgsize, true, smmu_domain);
>> + gather->pgsize, true, -1, smmu_domain);
>> }
>> static phys_addr_t
>
>