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From:   Liu Yi L <yi.l.liu@intel.com>
To:     alex.williamson@redhat.com, eric.auger@redhat.com,
        baolu.lu@linux.intel.com, joro@8bytes.org
Cc:     kevin.tian@intel.com, jacob.jun.pan@linux.intel.com,
        ashok.raj@intel.com, yi.l.liu@intel.com, jun.j.tian@intel.com,
        yi.y.sun@intel.com, jean-philippe@linaro.org, peterx@redhat.com,
        hao.wu@intel.com, iommu@lists.linux-foundation.org,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 02/15] iommu: Report domain nesting info
Date:   Thu, 11 Jun 2020 05:15:21 -0700
Message-Id: <1591877734-66527-3-git-send-email-yi.l.liu@intel.com>
In-Reply-To: <1591877734-66527-1-git-send-email-yi.l.liu@intel.com>
References: <1591877734-66527-1-git-send-email-yi.l.liu@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

IOMMUs that support nesting translation needs report the capability info
to userspace, e.g. the format of first level/stage paging structures.

Cc: Kevin Tian <kevin.tian@intel.com>
CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
@Jean, Eric: as nesting was introduced for ARM, but looks like no actual
user of it. right? So I'm wondering if we can reuse DOMAIN_ATTR_NESTING
to retrieve nesting info? how about your opinions?

 include/linux/iommu.h      |  1 +
 include/uapi/linux/iommu.h | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 78a26ae..f6e4b49 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -126,6 +126,7 @@ enum iommu_attr {
 	DOMAIN_ATTR_FSL_PAMUV1,
 	DOMAIN_ATTR_NESTING,	/* two stages of translation */
 	DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
+	DOMAIN_ATTR_NESTING_INFO,
 	DOMAIN_ATTR_MAX,
 };
 
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
index 303f148..02eac73 100644
--- a/include/uapi/linux/iommu.h
+++ b/include/uapi/linux/iommu.h
@@ -332,4 +332,38 @@ struct iommu_gpasid_bind_data {
 	};
 };
 
+struct iommu_nesting_info {
+	__u32	size;
+	__u32	format;
+	__u32	features;
+#define IOMMU_NESTING_FEAT_SYSWIDE_PASID	(1 << 0)
+#define IOMMU_NESTING_FEAT_BIND_PGTBL		(1 << 1)
+#define IOMMU_NESTING_FEAT_CACHE_INVLD		(1 << 2)
+	__u32	flags;
+	__u8	data[];
+};
+
+/*
+ * @flags:	VT-d specific flags. Currently reserved for future
+ *		extension.
+ * @addr_width:	The output addr width of first level/stage translation
+ * @pasid_bits:	Maximum supported PASID bits, 0 represents no PASID
+ *		support.
+ * @cap_reg:	Describe basic capabilities as defined in VT-d capability
+ *		register.
+ * @cap_mask:	Mark valid capability bits in @cap_reg.
+ * @ecap_reg:	Describe the extended capabilities as defined in VT-d
+ *		extended capability register.
+ * @ecap_mask:	Mark the valid capability bits in @ecap_reg.
+ */
+struct iommu_nesting_info_vtd {
+	__u32	flags;
+	__u16	addr_width;
+	__u16	pasid_bits;
+	__u64	cap_reg;
+	__u64	cap_mask;
+	__u64	ecap_reg;
+	__u64	ecap_mask;
+};
+
 #endif /* _UAPI_IOMMU_H */
-- 
2.7.4