From: Jason Gunthorpe <jgg@xxxxxxxxxx>
Now, ATC invalidation can be done with the vIOMMU invalidation op. A guest
owned IOMMU_DOMAIN_NESTED can do an ATS too. Allow it to pass in the EATS
field via the vSTE words.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 4 ++-
include/uapi/linux/iommufd.h | 2 +-
.../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 31 ++++++++++++++++---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 26 +++++++++++++---
4 files changed, 53 insertions(+), 10 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 8bd740f537ee..af25f092303f 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -305,7 +305,7 @@ static inline u32 arm_smmu_strtab_l2_idx(u32 sid)
#define STRTAB_STE_1_NESTING_ALLOWED \
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_S1STALLD | STRTAB_STE_1_EATS)
/*
* Context descriptors.
@@ -838,6 +838,7 @@ struct arm_smmu_domain {
struct arm_smmu_nested_domain {
struct iommu_domain domain;
struct arm_vsmmu *vsmmu;
+ bool enable_ats : 1;
__le64 ste[2];
};
@@ -879,6 +880,7 @@ struct arm_smmu_master_domain {
struct list_head devices_elm;
struct arm_smmu_master *master;
ioasid_t ssid;
+ bool nested_ats_flush : 1;
};
static inline struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 8e66e2fde1dd..056ba05a8022 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -404,7 +404,7 @@ struct iommu_hwpt_vtd_s1 {
* a user stage-1 Context Descriptor Table. Must be little-endian.
* Allowed fields: (Refer to "5.2 Stream Table Entry" in SMMUv3 HW Spec)
* - word-0: V, Cfg, S1Fmt, S1ContextPtr, S1CDMax
- * - word-1: S1DSS, S1CIR, S1COR, S1CSH, S1STALLD
+ * - word-1: EATS, S1DSS, S1CIR, S1COR, S1CSH, S1STALLD
*
* -EIO will be returned if @ste is not legal or contains any non-allowed field.
* Cfg can be used to select a S1, Bypass or Abort configuration. A Bypass
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 2479074db820..c0c5cd807d34 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
@@ -96,8 +96,6 @@ static int arm_smmu_attach_dev_nested(struct iommu_domain *domain,
.master = master,
.old_domain = iommu_get_domain_for_dev(dev),
.ssid = IOMMU_NO_PASID,
- /* Currently invalidation of ATC is not supported */
- .disable_ats = true,
};
struct arm_smmu_ste ste;
int ret;
@@ -108,6 +106,15 @@ static int arm_smmu_attach_dev_nested(struct iommu_domain *domain,
return -EBUSY;
mutex_lock(&arm_smmu_asid_lock);
+ /*
+ * The VM has to control the actual ATS state at the PCI device because
+ * we forward the invalidations directly from the VM. If the VM doesn't
+ * think ATS is on it will not generate ATC flushes and the ATC will
+ * become incoherent. Since we can't access the actual virtual PCI ATS
+ * config bit here base this off the EATS value in the STE. If the EATS
+ * is set then the VM must generate ATC flushes.
+ */
+ state.disable_ats = !nested_domain->enable_ats;
ret = arm_smmu_attach_prepare(&state, domain);
if (ret) {
mutex_unlock(&arm_smmu_asid_lock);
@@ -132,8 +139,10 @@ static const struct iommu_domain_ops arm_smmu_nested_ops = {
.free = arm_smmu_domain_nested_free,
};
-static int arm_smmu_validate_vste(struct iommu_hwpt_arm_smmuv3 *arg)
+static int arm_smmu_validate_vste(struct iommu_hwpt_arm_smmuv3 *arg,
+ bool *enable_ats)
{
+ unsigned int eats;
unsigned int cfg;
if (!(arg->ste[0] & cpu_to_le64(STRTAB_STE_0_V))) {
@@ -150,6 +159,18 @@ static int arm_smmu_validate_vste(struct iommu_hwpt_arm_smmuv3 *arg)
if (cfg != STRTAB_STE_0_CFG_ABORT && cfg != STRTAB_STE_0_CFG_BYPASS &&
cfg != STRTAB_STE_0_CFG_S1_TRANS)
return -EIO;
+
+ /*
+ * Only Full ATS or ATS UR is supported
+ * The EATS field will be set by arm_smmu_make_nested_domain_ste()
+ */
+ eats = FIELD_GET(STRTAB_STE_1_EATS, le64_to_cpu(arg->ste[1]));
+ arg->ste[1] &= ~cpu_to_le64(STRTAB_STE_1_EATS);
+ if (eats != STRTAB_STE_1_EATS_ABT && eats != STRTAB_STE_1_EATS_TRANS)
+ return -EIO;
+
+ if (cfg == STRTAB_STE_0_CFG_S1_TRANS)
+ *enable_ats = (eats == STRTAB_STE_1_EATS_TRANS);
return 0;
}
@@ -160,6 +181,7 @@ arm_vsmmu_alloc_domain_nested(struct iommufd_viommu *viommu,
struct arm_vsmmu *vsmmu = container_of(viommu, struct arm_vsmmu, core);
struct arm_smmu_nested_domain *nested_domain;
struct iommu_hwpt_arm_smmuv3 arg;
+ bool enable_ats = false;
int ret;
ret = iommu_copy_struct_from_user(&arg, user_data,
@@ -167,7 +189,7 @@ arm_vsmmu_alloc_domain_nested(struct iommufd_viommu *viommu,
if (ret)
return ERR_PTR(ret);
- ret = arm_smmu_validate_vste(&arg);
+ ret = arm_smmu_validate_vste(&arg, &enable_ats);
if (ret)
return ERR_PTR(ret);
@@ -177,6 +199,7 @@ arm_vsmmu_alloc_domain_nested(struct iommufd_viommu *viommu,
nested_domain->domain.type = IOMMU_DOMAIN_NESTED;
nested_domain->domain.ops = &arm_smmu_nested_ops;
+ nested_domain->enable_ats = enable_ats;
nested_domain->vsmmu = vsmmu;
nested_domain->ste[0] = arg.ste[0];
nested_domain->ste[1] = arg.ste[1] & ~cpu_to_le64(STRTAB_STE_1_EATS);
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 d1abfb42d828..10b4dbc8d027 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2107,7 +2107,16 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
if (!master->ats_enabled)
continue;
- arm_smmu_atc_inv_to_cmd(master_domain->ssid, iova, size, &cmd);
+ if (master_domain->nested_ats_flush) {
+ /*
+ * If a S2 used as a nesting parent is changed we have
+ * no option but to completely flush the ATC.
+ */
+ arm_smmu_atc_inv_to_cmd(IOMMU_NO_PASID, 0, 0, &cmd);
+ } else {
+ arm_smmu_atc_inv_to_cmd(master_domain->ssid, iova, size,
+ &cmd);
+ }
for (i = 0; i < master->num_streams; i++) {
cmd.atc.sid = master->streams[i].id;
@@ -2631,7 +2640,7 @@ static void arm_smmu_disable_pasid(struct arm_smmu_master *master)
static struct arm_smmu_master_domain *
arm_smmu_find_master_domain(struct arm_smmu_domain *smmu_domain,
struct arm_smmu_master *master,
- ioasid_t ssid)
+ ioasid_t ssid, bool nested_ats_flush)
{
struct arm_smmu_master_domain *master_domain;
@@ -2640,7 +2649,8 @@ arm_smmu_find_master_domain(struct arm_smmu_domain *smmu_domain,
list_for_each_entry(master_domain, &smmu_domain->devices,
devices_elm) {
if (master_domain->master == master &&
- master_domain->ssid == ssid)
+ master_domain->ssid == ssid &&
+ master_domain->nested_ats_flush == nested_ats_flush)
return master_domain;
}
return NULL;
@@ -2671,13 +2681,18 @@ static void arm_smmu_remove_master_domain(struct arm_smmu_master *master,
{
struct arm_smmu_domain *smmu_domain = to_smmu_domain_devices(domain);
struct arm_smmu_master_domain *master_domain;
+ bool nested_ats_flush = false;
unsigned long flags;
if (!smmu_domain)
return;
+ if (domain->type == IOMMU_DOMAIN_NESTED)
+ nested_ats_flush = to_smmu_nested_domain(domain)->enable_ats;
+
spin_lock_irqsave(&smmu_domain->devices_lock, flags);
- master_domain = arm_smmu_find_master_domain(smmu_domain, master, ssid);
+ master_domain = arm_smmu_find_master_domain(smmu_domain, master, ssid,
+ nested_ats_flush);
if (master_domain) {
list_del(&master_domain->devices_elm);
kfree(master_domain);
@@ -2744,6 +2759,9 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state,
return -ENOMEM;
master_domain->master = master;
master_domain->ssid = state->ssid;
+ if (new_domain->type == IOMMU_DOMAIN_NESTED)
+ master_domain->nested_ats_flush =
+ to_smmu_nested_domain(new_domain)->enable_ats;
/*
* During prepare we want the current smmu_domain and new
--
2.43.0
