2024-06-14 14:24:06

by Zong Li

[permalink] [raw]
Subject: [RFC PATCH v2 08/10] iommu/riscv: support nested iommu for flushing cache

This patch implements cache_invalidate_user operation for the userspace
to flush the hardware caches for a nested domain through iommufd.

Signed-off-by: Zong Li <[email protected]>
---
drivers/iommu/riscv/iommu.c | 90 ++++++++++++++++++++++++++++++++++--
include/uapi/linux/iommufd.h | 11 +++++
2 files changed, 97 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index 410b236e9b24..d08eb0a2939e 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1587,8 +1587,9 @@ static int riscv_iommu_attach_dev_nested(struct iommu_domain *domain, struct dev
if (riscv_iommu_bond_link(riscv_domain, dev))
return -ENOMEM;

- riscv_iommu_iotlb_inval(riscv_domain, 0, ULONG_MAX);
- info->dc_user.ta |= RISCV_IOMMU_PC_TA_V;
+ if (riscv_iommu_bond_link(info->domain, dev))
+ return -ENOMEM;
+
riscv_iommu_iodir_update(iommu, dev, &info->dc_user);

info->domain = riscv_domain;
@@ -1611,13 +1612,92 @@ static void riscv_iommu_domain_free_nested(struct iommu_domain *domain)
kfree(riscv_domain);
}

+static int riscv_iommu_fix_user_cmd(struct riscv_iommu_command *cmd,
+ unsigned int pscid, unsigned int gscid)
+{
+ u32 opcode = FIELD_GET(RISCV_IOMMU_CMD_OPCODE, cmd->dword0);
+
+ switch (opcode) {
+ case RISCV_IOMMU_CMD_IOTINVAL_OPCODE:
+ u32 func = FIELD_GET(RISCV_IOMMU_CMD_FUNC, cmd->dword0);
+
+ if (func != RISCV_IOMMU_CMD_IOTINVAL_FUNC_GVMA &&
+ func != RISCV_IOMMU_CMD_IOTINVAL_FUNC_VMA) {
+ pr_warn("The IOTINVAL function: 0x%x is not supported\n",
+ func);
+ return -EOPNOTSUPP;
+ }
+
+ if (func == RISCV_IOMMU_CMD_IOTINVAL_FUNC_GVMA) {
+ cmd->dword0 &= ~RISCV_IOMMU_CMD_FUNC;
+ cmd->dword0 |= FIELD_PREP(RISCV_IOMMU_CMD_FUNC,
+ RISCV_IOMMU_CMD_IOTINVAL_FUNC_VMA);
+ }
+
+ cmd->dword0 &= ~(RISCV_IOMMU_CMD_IOTINVAL_PSCID |
+ RISCV_IOMMU_CMD_IOTINVAL_GSCID);
+ riscv_iommu_cmd_inval_set_pscid(cmd, pscid);
+ riscv_iommu_cmd_inval_set_gscid(cmd, gscid);
+ break;
+ case RISCV_IOMMU_CMD_IODIR_OPCODE:
+ /*
+ * Ensure the device ID is right. We expect that VMM has
+ * transferred the device ID to host's from guest's.
+ */
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int riscv_iommu_cache_invalidate_user(struct iommu_domain *domain,
+ struct iommu_user_data_array *array)
+{
+ struct riscv_iommu_domain *riscv_domain = iommu_domain_to_riscv(domain);
+ struct iommu_hwpt_riscv_iommu_invalidate inv_info;
+ int ret, index;
+
+ if (array->type != IOMMU_HWPT_INVALIDATE_DATA_RISCV_IOMMU) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ for (index = 0; index < array->entry_num; index++) {
+ ret = iommu_copy_struct_from_user_array(&inv_info, array,
+ IOMMU_HWPT_INVALIDATE_DATA_RISCV_IOMMU,
+ index, cmd);
+ if (ret)
+ break;
+
+ ret = riscv_iommu_fix_user_cmd((struct riscv_iommu_command *)inv_info.cmd,
+ riscv_domain->pscid,
+ riscv_domain->s2->gscid);
+ if (ret == -EOPNOTSUPP)
+ continue;
+
+ riscv_iommu_cmd_send(riscv_domain->iommu,
+ (struct riscv_iommu_command *)inv_info.cmd);
+ riscv_iommu_cmd_sync(riscv_domain->iommu,
+ RISCV_IOMMU_IOTINVAL_TIMEOUT);
+ }
+
+out:
+ array->entry_num = index;
+
+ return ret;
+}
+
static const struct iommu_domain_ops riscv_iommu_nested_domain_ops = {
.attach_dev = riscv_iommu_attach_dev_nested,
.free = riscv_iommu_domain_free_nested,
+ .cache_invalidate_user = riscv_iommu_cache_invalidate_user,
};

static int
-riscv_iommu_get_dc_user(struct device *dev, struct iommu_hwpt_riscv_iommu *user_arg)
+riscv_iommu_get_dc_user(struct device *dev, struct iommu_hwpt_riscv_iommu *user_arg,
+ struct riscv_iommu_domain *s1_domain)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct riscv_iommu_device *iommu = dev_to_iommu(dev);
@@ -1663,6 +1743,8 @@ riscv_iommu_get_dc_user(struct device *dev, struct iommu_hwpt_riscv_iommu *user_
riscv_iommu_get_dc(iommu, fwspec->ids[i]),
sizeof(struct riscv_iommu_dc));
info->dc_user.fsc = dc.fsc;
+ info->dc_user.ta = FIELD_PREP(RISCV_IOMMU_PC_TA_PSCID, s1_domain->pscid) |
+ RISCV_IOMMU_PC_TA_V;
}

return 0;
@@ -1708,7 +1790,7 @@ riscv_iommu_domain_alloc_nested(struct device *dev,
}

/* Get device context of stage-1 from user*/
- ret = riscv_iommu_get_dc_user(dev, &arg);
+ ret = riscv_iommu_get_dc_user(dev, &arg, s1_domain);
if (ret) {
kfree(s1_domain);
return ERR_PTR(-EINVAL);
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 514463fe85d3..876cbe980a42 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -653,9 +653,11 @@ struct iommu_hwpt_get_dirty_bitmap {
* enum iommu_hwpt_invalidate_data_type - IOMMU HWPT Cache Invalidation
* Data Type
* @IOMMU_HWPT_INVALIDATE_DATA_VTD_S1: Invalidation data for VTD_S1
+ * @IOMMU_HWPT_INVALIDATE_DATA_RISCV_IOMMU: Invalidation data for RISCV_IOMMU
*/
enum iommu_hwpt_invalidate_data_type {
IOMMU_HWPT_INVALIDATE_DATA_VTD_S1,
+ IOMMU_HWPT_INVALIDATE_DATA_RISCV_IOMMU,
};

/**
@@ -694,6 +696,15 @@ struct iommu_hwpt_vtd_s1_invalidate {
__u32 __reserved;
};

+/**
+ * struct iommu_hwpt_riscv_iommu_invalidate - RISCV IOMMU cache invalidation
+ * (IOMMU_HWPT_TYPE_RISCV_IOMMU)
+ * @cmd: An array holds a command for cache invalidation
+ */
+struct iommu_hwpt_riscv_iommu_invalidate {
+ __aligned_u64 cmd[2];
+};
+
/**
* struct iommu_hwpt_invalidate - ioctl(IOMMU_HWPT_INVALIDATE)
* @size: sizeof(struct iommu_hwpt_invalidate)
--
2.17.1



2024-06-15 03:24:36

by Lu Baolu

[permalink] [raw]
Subject: Re: [RFC PATCH v2 08/10] iommu/riscv: support nested iommu for flushing cache

On 6/14/24 10:21 PM, Zong Li wrote:
> This patch implements cache_invalidate_user operation for the userspace
> to flush the hardware caches for a nested domain through iommufd.

$ grep "This patch" Documentation/process/submitting-patches.rst

Same to other commit messages.

Best regards,
baolu