2023-09-21 23:05:36

by Yi Liu

Subject: [PATCH v5 06/11] iommu/vt-d: Set the nested domain to a device

This adds the helper for setting the nested domain to a device hence
enable nested domain usage on Intel VT-d.

Signed-off-by: Jacob Pan <[email protected]>
Signed-off-by: Lu Baolu <[email protected]>
Signed-off-by: Yi Liu <[email protected]>
---
drivers/iommu/intel/nested.c | 50 ++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)

diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index 012d5ff60265..f9c6ade72416 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -11,8 +11,57 @@
#define pr_fmt(fmt) "DMAR: " fmt

#include <linux/iommu.h>
+#include <linux/pci.h>
+#include <linux/pci-ats.h>

#include "iommu.h"
+#include "pasid.h"
+
+static int intel_nested_attach_dev(struct iommu_domain *domain,
+ struct device *dev)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct intel_iommu *iommu = info->iommu;
+ unsigned long flags;
+ int ret = 0;
+
+ if (info->domain)
+ device_block_translation(dev);
+
+ if (iommu->agaw < dmar_domain->s2_domain->agaw) {
+ dev_err_ratelimited(dev, "Adjusted guest address width not compatible\n");
+ return -ENODEV;
+ }
+
+ /* Is s2_domain compatible with this IOMMU? */
+ ret = prepare_domain_attach_device(&dmar_domain->s2_domain->domain, dev);
+ if (ret) {
+ dev_err_ratelimited(dev, "s2 domain is not compatible\n");
+ return ret;
+ }
+
+ ret = domain_attach_iommu(dmar_domain, iommu);
+ if (ret) {
+ dev_err_ratelimited(dev, "Failed to attach domain to iommu\n");
+ return ret;
+ }
+
+ ret = intel_pasid_setup_nested(iommu, dev,
+ IOMMU_NO_PASID, dmar_domain);
+ if (ret) {
+ domain_detach_iommu(dmar_domain, iommu);
+ dev_err_ratelimited(dev, "Failed to setup pasid entry\n");
+ return ret;
+ }
+
+ info->domain = dmar_domain;
+ spin_lock_irqsave(&dmar_domain->lock, flags);
+ list_add(&info->link, &dmar_domain->devices);
+ spin_unlock_irqrestore(&dmar_domain->lock, flags);
+
+ return 0;
+}

static void intel_nested_domain_free(struct iommu_domain *domain)
{
@@ -20,6 +69,7 @@ static void intel_nested_domain_free(struct iommu_domain *domain)
}

static const struct iommu_domain_ops intel_nested_domain_ops = {
+ .attach_dev = intel_nested_attach_dev,
.free = intel_nested_domain_free,
};

--
2.34.1

2023-09-27 07:53:30

by Tian, Kevin

Subject: RE: [PATCH v5 06/11] iommu/vt-d: Set the nested domain to a device

> From: Liu, Yi L <[email protected]>
> Sent: Thursday, September 21, 2023 3:54 PM
>
> +
> + /* Is s2_domain compatible with this IOMMU? */

Add more words on why prepare_attach uses s2_domain when the actual
attach is for s1

> + ret = prepare_domain_attach_device(&dmar_domain->s2_domain-
> >domain, dev);
> + if (ret) {
> + dev_err_ratelimited(dev, "s2 domain is not compatible\n");
> + return ret;
> + }
> +
> + ret = domain_attach_iommu(dmar_domain, iommu);
> + if (ret) {
> + dev_err_ratelimited(dev, "Failed to attach domain to
> iommu\n");
> + return ret;
> + }
> +