| Message ID | be799951a817557ac093ac3e18d02a631306aa35.1740238876.git.nicolinc@nvidia.com |
|---|---|
| State | New |
| Headers | show |
| Series | iommufd: Add vIOMMU infrastructure (Part-3: vEVENTQ) | expand |
oN sAt, Feb 22, 2025 at 07:54:09AM -0800, Nicolin Chen wrote: > 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 5aa2e7af58b4..364d8469a480 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 > @@ -85,6 +85,59 @@ static void arm_smmu_make_nested_domain_ste( > } > } > > +int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state, > + struct iommu_domain *domain) > +{ > + struct arm_smmu_nested_domain *nested_domain; > + struct arm_smmu_vmaster *vmaster; > + unsigned long vsid; > + int ret; > + > + iommu_group_mutex_assert(state->master->dev); > + > + if (domain->type != IOMMU_DOMAIN_NESTED) > + return 0; > + nested_domain = to_smmu_nested_domain(domain); > + > + /* Skip invalid vSTE */ > + if (!(nested_domain->ste[0] & cpu_to_le64(STRTAB_STE_0_V))) > + return 0; > + > + ret = iommufd_viommu_get_vdev_id(&nested_domain->vsmmu->core, > + state->master->dev, &vsid); > + if (ret) > + return ret; > + > + vmaster = kzalloc(sizeof(*vmaster), GFP_KERNEL); > + if (!vmaster) > + return -ENOMEM; > + vmaster->vsmmu = nested_domain->vsmmu; > + vmaster->vsid = vsid; > + state->vmaster = vmaster; > + > + return 0; > +} > + > +void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state) > +{ > + struct arm_smmu_master *master = state->master; > + > + mutex_lock(&master->smmu->streams_mutex); > + if (state->vmaster != master->vmaster) { > + kfree(master->vmaster); > + master->vmaster = state->vmaster; > + } Does this condition suggest that we might end up calling `arm_smmu_attach_prepare_vmaster()` multiple times before __actually__ commiting to a vmaster? > + mutex_unlock(&master->smmu->streams_mutex); > +} > + > +void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master) > +{ > + mutex_lock(&master->smmu->streams_mutex); > + kfree(master->vmaster); > + master->vmaster = NULL; > + mutex_unlock(&master->smmu->streams_mutex); > +} > + > static int arm_smmu_attach_dev_nested(struct iommu_domain *domain, > struct device *dev) > { > 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 358072b4e293..9e50bcee69d1 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > @@ -2803,6 +2803,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, > struct arm_smmu_domain *smmu_domain = > to_smmu_domain_devices(new_domain); > unsigned long flags; > + int ret; > > /* > * arm_smmu_share_asid() must not see two domains pointing to the same > @@ -2832,9 +2833,15 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, > } > > if (smmu_domain) { > + ret = arm_smmu_attach_prepare_vmaster(state, new_domain); IMO, this adds a little confusion for folks not using iommufd. I guess it'd be cleaner if we invoke this below within the: `if (new_domain->type == IOMMU_DOMAIN_NESTED)` condition instead of simply returning from the function if the new_domain->type isn't NESTED. > + if (ret) > + return ret; > + > master_domain = kzalloc(sizeof(*master_domain), GFP_KERNEL); > - if (!master_domain) > + if (!master_domain) { > + kfree(state->vmaster); > return -ENOMEM; > + } > master_domain->master = master; > master_domain->ssid = state->ssid; > if (new_domain->type == IOMMU_DOMAIN_NESTED) > @@ -2861,6 +2868,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, > spin_unlock_irqrestore(&smmu_domain->devices_lock, > flags); > kfree(master_domain); > + kfree(state->vmaster); > return -EINVAL; > } > > @@ -2893,6 +2901,8 @@ void arm_smmu_attach_commit(struct arm_smmu_attach_state *state) > > lockdep_assert_held(&arm_smmu_asid_lock); > > + arm_smmu_attach_commit_vmaster(state); > + > if (state->ats_enabled && !master->ats_enabled) { > arm_smmu_enable_ats(master); > } else if (state->ats_enabled && master->ats_enabled) { > @@ -3162,6 +3172,7 @@ static int arm_smmu_attach_dev_identity(struct iommu_domain *domain, > struct arm_smmu_ste ste; > struct arm_smmu_master *master = dev_iommu_priv_get(dev); > > + arm_smmu_master_clear_vmaster(master); > arm_smmu_make_bypass_ste(master->smmu, &ste); > arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_BYPASS); > return 0; > @@ -3180,7 +3191,9 @@ static int arm_smmu_attach_dev_blocked(struct iommu_domain *domain, > struct device *dev) > { > struct arm_smmu_ste ste; > + struct arm_smmu_master *master = dev_iommu_priv_get(dev); > > + arm_smmu_master_clear_vmaster(master); > arm_smmu_make_abort_ste(&ste); > arm_smmu_attach_dev_ste(domain, dev, &ste, > STRTAB_STE_1_S1DSS_TERMINATE); > Thanks, Praan
On Mon, Feb 24, 2025 at 02:24:55PM -0800, Nicolin Chen wrote: > On Mon, Feb 24, 2025 at 09:53:58PM +0000, Pranjal Shrivastava wrote: > > On Mon, Feb 24, 2025 at 01:31:11PM -0800, Nicolin Chen wrote: > > > On Mon, Feb 24, 2025 at 08:35:56PM +0000, Pranjal Shrivastava wrote: > > > > oN sAt, Feb 22, 2025 at 07:54:09AM -0800, Nicolin Chen wrote: > > > > > 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 5aa2e7af58b4..364d8469a480 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 > > > > > @@ -85,6 +85,59 @@ static void arm_smmu_make_nested_domain_ste( > > > > > } > > > > > } > > > > > > > > > > +int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state, > > > > > + struct iommu_domain *domain) > > > > > +{ > > > > > + struct arm_smmu_nested_domain *nested_domain; > > > > > + struct arm_smmu_vmaster *vmaster; > > > > > + unsigned long vsid; > > > > > + int ret; > > > > > + > > > > > + iommu_group_mutex_assert(state->master->dev); > > > > > + > > > > > + if (domain->type != IOMMU_DOMAIN_NESTED) > > > > > + return 0; > > > > > + nested_domain = to_smmu_nested_domain(domain); > > > > > + > > > > > + /* Skip invalid vSTE */ > > > > > + if (!(nested_domain->ste[0] & cpu_to_le64(STRTAB_STE_0_V))) > > > > > + return 0; > > > > > + > > > > > + ret = iommufd_viommu_get_vdev_id(&nested_domain->vsmmu->core, > > > > > + state->master->dev, &vsid); > > > > > + if (ret) > > > > > + return ret; > > > > > + > > > > > + vmaster = kzalloc(sizeof(*vmaster), GFP_KERNEL); > > > > > + if (!vmaster) > > > > > + return -ENOMEM; > > > > > + vmaster->vsmmu = nested_domain->vsmmu; > > > > > + vmaster->vsid = vsid; > > > > > + state->vmaster = vmaster; > > > > > + > > > > > + return 0; > > > > > +} > > > > > + > > > > > +void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state) > > > > > +{ > > > > > + struct arm_smmu_master *master = state->master; > > > > > + > > > > > + mutex_lock(&master->smmu->streams_mutex); > > > > > + if (state->vmaster != master->vmaster) { > > > > > + kfree(master->vmaster); > > > > > + master->vmaster = state->vmaster; > > > > > + } > > > > > > > > Does this condition suggest that we might end up calling > > > > `arm_smmu_attach_prepare_vmaster()` multiple times before __actually__ > > > > commiting to a vmaster? > > > > > > No. prepare() and commit() are 1:1. How is it interpreted to have > > > "multiple times"? > > > > Ohh alright. I was just confused about why do we need to check: > > `if (state->vmaster != master->vmaster)` ? > > Hmm, it's probably not necessary, since we always allocate a new > vmaster pointer to the "state" or set a NULL. > > I will clean that up a bit. I made the following change on top of this patch (will squash): ------------------------------------------------------------- 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 364d8469a480..2c1a51c360fe 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 @@ -95,8 +95,6 @@ int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state, iommu_group_mutex_assert(state->master->dev); - if (domain->type != IOMMU_DOMAIN_NESTED) - return 0; nested_domain = to_smmu_nested_domain(domain); /* Skip invalid vSTE */ @@ -122,19 +120,9 @@ void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state) { struct arm_smmu_master *master = state->master; - mutex_lock(&master->smmu->streams_mutex); - if (state->vmaster != master->vmaster) { - kfree(master->vmaster); - master->vmaster = state->vmaster; - } - mutex_unlock(&master->smmu->streams_mutex); -} - -void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master) -{ mutex_lock(&master->smmu->streams_mutex); kfree(master->vmaster); - master->vmaster = NULL; + master->vmaster = state->vmaster; mutex_unlock(&master->smmu->streams_mutex); } 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 9e50bcee69d1..b9d0cf571da0 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2833,9 +2833,11 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, } if (smmu_domain) { - ret = arm_smmu_attach_prepare_vmaster(state, new_domain); - if (ret) - return ret; + if (new_domain->type == IOMMU_DOMAIN_NESTED) { + ret = arm_smmu_attach_prepare_vmaster(state, new_domain); + if (ret) + return ret; + } master_domain = kzalloc(sizeof(*master_domain), GFP_KERNEL); if (!master_domain) { @@ -3171,8 +3173,9 @@ static int arm_smmu_attach_dev_identity(struct iommu_domain *domain, { struct arm_smmu_ste ste; struct arm_smmu_master *master = dev_iommu_priv_get(dev); + struct arm_smmu_attach_state state = { .master = master }; - arm_smmu_master_clear_vmaster(master); + arm_smmu_attach_commit_vmaster(&state); arm_smmu_make_bypass_ste(master->smmu, &ste); arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_BYPASS); return 0; @@ -3192,8 +3195,9 @@ static int arm_smmu_attach_dev_blocked(struct iommu_domain *domain, { struct arm_smmu_ste ste; struct arm_smmu_master *master = dev_iommu_priv_get(dev); + struct arm_smmu_attach_state state = { .master = master }; - arm_smmu_master_clear_vmaster(master); + arm_smmu_attach_commit_vmaster(&state); arm_smmu_make_abort_ste(&ste); arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_TERMINATE); 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 85352504343b..eeec302f1b4b 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -1066,7 +1066,6 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev, int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state, struct iommu_domain *domain); void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state); -void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master); #else #define arm_smmu_hw_info NULL #define arm_vsmmu_alloc NULL @@ -1082,9 +1081,6 @@ static inline void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state) { } -static inline void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master) -{ -} #endif /* CONFIG_ARM_SMMU_V3_IOMMUFD */ #endif /* _ARM_SMMU_V3_H */ ------------------------------------------------------------- Thanks Nicolin
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 bd9d7c85576a..85352504343b 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -799,6 +799,11 @@ struct arm_smmu_stream { struct rb_node node; }; +struct arm_smmu_vmaster { + struct arm_vsmmu *vsmmu; + unsigned long vsid; +}; + struct arm_smmu_event { u8 stall : 1, ssv : 1, @@ -824,6 +829,8 @@ struct arm_smmu_master { struct arm_smmu_device *smmu; struct device *dev; struct arm_smmu_stream *streams; + /* Locked by smmu->streams_mutex */ + struct arm_smmu_vmaster *vmaster; /* Locked by the iommu core using the group mutex */ struct arm_smmu_ctx_desc_cfg cd_table; unsigned int num_streams; @@ -972,6 +979,7 @@ struct arm_smmu_attach_state { bool disable_ats; ioasid_t ssid; /* Resulting state */ + struct arm_smmu_vmaster *vmaster; bool ats_enabled; }; @@ -1055,9 +1063,28 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev, struct iommu_domain *parent, struct iommufd_ctx *ictx, unsigned int viommu_type); +int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state, + struct iommu_domain *domain); +void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state); +void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master); #else #define arm_smmu_hw_info NULL #define arm_vsmmu_alloc NULL + +static inline int +arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state, + struct iommu_domain *domain) +{ + return 0; /* NOP */ +} + +static inline void +arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state) +{ +} +static inline void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master) +{ +} #endif /* CONFIG_ARM_SMMU_V3_IOMMUFD */ #endif /* _ARM_SMMU_V3_H */ 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 5aa2e7af58b4..364d8469a480 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 @@ -85,6 +85,59 @@ static void arm_smmu_make_nested_domain_ste( } } +int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state, + struct iommu_domain *domain) +{ + struct arm_smmu_nested_domain *nested_domain; + struct arm_smmu_vmaster *vmaster; + unsigned long vsid; + int ret; + + iommu_group_mutex_assert(state->master->dev); + + if (domain->type != IOMMU_DOMAIN_NESTED) + return 0; + nested_domain = to_smmu_nested_domain(domain); + + /* Skip invalid vSTE */ + if (!(nested_domain->ste[0] & cpu_to_le64(STRTAB_STE_0_V))) + return 0; + + ret = iommufd_viommu_get_vdev_id(&nested_domain->vsmmu->core, + state->master->dev, &vsid); + if (ret) + return ret; + + vmaster = kzalloc(sizeof(*vmaster), GFP_KERNEL); + if (!vmaster) + return -ENOMEM; + vmaster->vsmmu = nested_domain->vsmmu; + vmaster->vsid = vsid; + state->vmaster = vmaster; + + return 0; +} + +void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state) +{ + struct arm_smmu_master *master = state->master; + + mutex_lock(&master->smmu->streams_mutex); + if (state->vmaster != master->vmaster) { + kfree(master->vmaster); + master->vmaster = state->vmaster; + } + mutex_unlock(&master->smmu->streams_mutex); +} + +void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master) +{ + mutex_lock(&master->smmu->streams_mutex); + kfree(master->vmaster); + master->vmaster = NULL; + mutex_unlock(&master->smmu->streams_mutex); +} + static int arm_smmu_attach_dev_nested(struct iommu_domain *domain, struct device *dev) { 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 358072b4e293..9e50bcee69d1 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2803,6 +2803,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, struct arm_smmu_domain *smmu_domain = to_smmu_domain_devices(new_domain); unsigned long flags; + int ret; /* * arm_smmu_share_asid() must not see two domains pointing to the same @@ -2832,9 +2833,15 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, } if (smmu_domain) { + ret = arm_smmu_attach_prepare_vmaster(state, new_domain); + if (ret) + return ret; + master_domain = kzalloc(sizeof(*master_domain), GFP_KERNEL); - if (!master_domain) + if (!master_domain) { + kfree(state->vmaster); return -ENOMEM; + } master_domain->master = master; master_domain->ssid = state->ssid; if (new_domain->type == IOMMU_DOMAIN_NESTED) @@ -2861,6 +2868,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, spin_unlock_irqrestore(&smmu_domain->devices_lock, flags); kfree(master_domain); + kfree(state->vmaster); return -EINVAL; } @@ -2893,6 +2901,8 @@ void arm_smmu_attach_commit(struct arm_smmu_attach_state *state) lockdep_assert_held(&arm_smmu_asid_lock); + arm_smmu_attach_commit_vmaster(state); + if (state->ats_enabled && !master->ats_enabled) { arm_smmu_enable_ats(master); } else if (state->ats_enabled && master->ats_enabled) { @@ -3162,6 +3172,7 @@ static int arm_smmu_attach_dev_identity(struct iommu_domain *domain, struct arm_smmu_ste ste; struct arm_smmu_master *master = dev_iommu_priv_get(dev); + arm_smmu_master_clear_vmaster(master); arm_smmu_make_bypass_ste(master->smmu, &ste); arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_BYPASS); return 0; @@ -3180,7 +3191,9 @@ static int arm_smmu_attach_dev_blocked(struct iommu_domain *domain, struct device *dev) { struct arm_smmu_ste ste; + struct arm_smmu_master *master = dev_iommu_priv_get(dev); + arm_smmu_master_clear_vmaster(master); arm_smmu_make_abort_ste(&ste); arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_TERMINATE);
Use it to store all vSMMU-related data. The vsid (Virtual Stream ID) will be the first use case. Since the vsid reader will be the eventq handler that already holds a streams_mutex, reuse that to fenche the vmaster too. Also add a pair of arm_smmu_attach_prepare/commit_vmaster helpers to set or unset the master->vmaster point. Put these helpers inside the existing arm_smmu_attach_prepare/commit(). For identity/blocked ops that don't call arm_smmu_attach_prepare/commit(), add a simpler arm_smmu_master_clear_vmaster helper to unset the vmaster. Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 27 ++++++++++ .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 53 +++++++++++++++++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 +++++- 3 files changed, 94 insertions(+), 1 deletion(-)