Messages in this thread | | | From | Shameerali Kolothum Thodi <> | Subject | RE: [PATCH v14 13/13] iommu/smmuv3: Accept configs with more than one context descriptor | Date | Thu, 1 Apr 2021 12:38:16 +0000 |
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> -----Original Message----- > From: Auger Eric [mailto:eric.auger@redhat.com] > Sent: 01 April 2021 12:49 > To: yuzenghui <yuzenghui@huawei.com> > Cc: eric.auger.pro@gmail.com; iommu@lists.linux-foundation.org; > linux-kernel@vger.kernel.org; kvm@vger.kernel.org; > kvmarm@lists.cs.columbia.edu; will@kernel.org; maz@kernel.org; > robin.murphy@arm.com; joro@8bytes.org; alex.williamson@redhat.com; > tn@semihalf.com; zhukeqian <zhukeqian1@huawei.com>; > jacob.jun.pan@linux.intel.com; yi.l.liu@intel.com; wangxingang > <wangxingang5@huawei.com>; jiangkunkun <jiangkunkun@huawei.com>; > jean-philippe@linaro.org; zhangfei.gao@linaro.org; zhangfei.gao@gmail.com; > vivek.gautam@arm.com; Shameerali Kolothum Thodi > <shameerali.kolothum.thodi@huawei.com>; nicoleotsuka@gmail.com; > lushenming <lushenming@huawei.com>; vsethi@nvidia.com; Wanghaibin (D) > <wanghaibin.wang@huawei.com> > Subject: Re: [PATCH v14 13/13] iommu/smmuv3: Accept configs with more than > one context descriptor > > Hi Zenghui, > > On 3/30/21 11:23 AM, Zenghui Yu wrote: > > Hi Eric, > > > > On 2021/2/24 4:56, Eric Auger wrote: > >> In preparation for vSVA, let's accept userspace provided configs > >> with more than one CD. We check the max CD against the host iommu > >> capability and also the format (linear versus 2 level). > >> > >> Signed-off-by: Eric Auger <eric.auger@redhat.com> > >> Signed-off-by: Shameer Kolothum > <shameerali.kolothum.thodi@huawei.com> > >> --- > >> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 13 ++++++++----- > >> 1 file changed, 8 insertions(+), 5 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 332d31c0680f..ab74a0289893 100644 > >> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > >> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > >> @@ -3038,14 +3038,17 @@ static int > arm_smmu_attach_pasid_table(struct > >> iommu_domain *domain, > >> if (smmu_domain->s1_cfg.set) > >> goto out; > >> - /* > >> - * we currently support a single CD so s1fmt and s1dss > >> - * fields are also ignored > >> - */ > >> - if (cfg->pasid_bits) > >> + list_for_each_entry(master, &smmu_domain->devices, > >> domain_head) { > >> + if (cfg->pasid_bits > master->ssid_bits) > >> + goto out; > >> + } > >> + if (cfg->vendor_data.smmuv3.s1fmt == > >> STRTAB_STE_0_S1FMT_64K_L2 && > >> + !(smmu->features & > ARM_SMMU_FEAT_2_LVL_CDTAB)) > >> goto out; > >> smmu_domain->s1_cfg.cdcfg.cdtab_dma = cfg->base_ptr; > >> + smmu_domain->s1_cfg.s1cdmax = cfg->pasid_bits; > >> + smmu_domain->s1_cfg.s1fmt = > cfg->vendor_data.smmuv3.s1fmt; > > > > And what about the SIDSS field? > > > I added this patch upon Shameer's request, to be more vSVA friendly. > Hower this series does not really target multiple CD support. At the > moment the driver only supports STRTAB_STE_1_S1DSS_SSID0 (0x2) I think. > At this moment maybe I can only check the s1dss field is 0x2. Or simply > removes this patch? > > Thoughts?
Right. This was useful for vSVA tests. But yes, to properly support multiple CDs we need to pass the S1DSS from Qemu. And that requires further changes. So I think it's better to remove this patch and reject S1CDMAX != 0 cases.
Thanks, Shameer
> > Eric
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