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From: Eric Auger <eric.auger@redhat.com>
To: eric.auger.pro@gmail.com, eric.auger@redhat.com,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
	joro@8bytes.org, alex.williamson@redhat.com,
	jacob.jun.pan@linux.intel.com, yi.l.liu@intel.com,
	jean-philippe.brucker@arm.com, will.deacon@arm.com,
	robin.murphy@arm.com
Cc: marc.zyngier@arm.com, kevin.tian@intel.com,
	vincent.stehle@arm.com, ashok.raj@intel.com
Subject: [PATCH v8 10/29] iommu: Introduce bind/unbind_guest_msi
Date: Sun, 26 May 2019 18:09:45 +0200
Message-ID: <20190526161004.25232-11-eric.auger@redhat.com> (raw)
In-Reply-To: <20190526161004.25232-1-eric.auger@redhat.com>

On ARM, MSI are translated by the SMMU. An IOVA is allocated
for each MSI doorbell. If both the host and the guest are exposed
with SMMUs, we end up with 2 different IOVAs allocated by each.
guest allocates an IOVA (gIOVA) to map onto the guest MSI
doorbell (gDB). The Host allocates another IOVA (hIOVA) to map
onto the physical doorbell (hDB).

So we end up with 2 untied mappings:
         S1            S2
gIOVA    ->    gDB
              hIOVA    ->    hDB

Currently the PCI device is programmed by the host with hIOVA
as MSI doorbell. So this does not work.

This patch introduces an API to pass gIOVA/gDB to the host so
that gIOVA can be reused by the host instead of re-allocating
a new IOVA. So the goal is to create the following nested mapping:

         S1            S2
gIOVA    ->    gDB     ->    hDB

and program the PCI device with gIOVA MSI doorbell.

In case we have several devices attached to this nested domain
(devices belonging to the same group), they cannot be isolated
on guest side either. So they should also end up in the same domain
on guest side. We will enforce that all the devices attached to
the host iommu domain use the same physical doorbell and similarly
a single virtual doorbell mapping gets registered (1 single
virtual doorbell is used on guest as well).

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
v7 -> v8:
- dummy iommu_unbind_guest_msi turned into a void function

v6 -> v7:
- remove the device handle parameter.
- Add comments saying there can only be a single MSI binding
  registered per iommu_domain
v5 -> v6:
-fix compile issue when IOMMU_API is not set

v3 -> v4:
- add unbind

v2 -> v3:
- add a struct device handle
---
 drivers/iommu/iommu.c | 37 +++++++++++++++++++++++++++++++++++++
 include/linux/iommu.h | 20 ++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 1758b574c722..eb8c95eb2d5a 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1662,6 +1662,43 @@ static void __iommu_detach_device(struct iommu_domain *domain,
 	trace_detach_device_from_domain(dev);
 }
 
+/**
+ * iommu_bind_guest_msi - Passes the stage1 GIOVA/GPA mapping of a
+ * virtual doorbell
+ *
+ * @domain: iommu domain the stage 1 mapping will be attached to
+ * @iova: iova allocated by the guest
+ * @gpa: guest physical address of the virtual doorbell
+ * @size: granule size used for the mapping
+ *
+ * The associated IOVA can be reused by the host to create a nested
+ * stage2 binding mapping translating into the physical doorbell used
+ * by the devices attached to the domain.
+ *
+ * All devices within the domain must share the same physical doorbell.
+ * A single MSI GIOVA/GPA mapping can be attached to an iommu_domain.
+ */
+
+int iommu_bind_guest_msi(struct iommu_domain *domain,
+			 dma_addr_t giova, phys_addr_t gpa, size_t size)
+{
+	if (unlikely(!domain->ops->bind_guest_msi))
+		return -ENODEV;
+
+	return domain->ops->bind_guest_msi(domain, giova, gpa, size);
+}
+EXPORT_SYMBOL_GPL(iommu_bind_guest_msi);
+
+void iommu_unbind_guest_msi(struct iommu_domain *domain,
+			    dma_addr_t iova)
+{
+	if (unlikely(!domain->ops->unbind_guest_msi))
+		return;
+
+	domain->ops->unbind_guest_msi(domain, iova);
+}
+EXPORT_SYMBOL_GPL(iommu_unbind_guest_msi);
+
 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
 {
 	struct iommu_group *group;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 7a37336e5d7f..9e397f423333 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -267,6 +267,8 @@ struct page_response_msg {
  * @attach_pasid_table: attach a pasid table
  * @detach_pasid_table: detach the pasid table
  * @cache_invalidate: invalidate translation caches
+ * @bind_guest_msi: provides a stage1 giova/gpa MSI doorbell mapping
+ * @unbind_guest_msi: withdraw a stage1 giova/gpa MSI doorbell mapping
  * @pgsize_bitmap: bitmap of all possible supported page sizes
  */
 struct iommu_ops {
@@ -334,6 +336,10 @@ struct iommu_ops {
 	int (*cache_invalidate)(struct iommu_domain *domain, struct device *dev,
 				struct iommu_cache_invalidate_info *inv_info);
 
+	int (*bind_guest_msi)(struct iommu_domain *domain,
+			      dma_addr_t giova, phys_addr_t gpa, size_t size);
+	void (*unbind_guest_msi)(struct iommu_domain *domain, dma_addr_t giova);
+
 	unsigned long pgsize_bitmap;
 };
 
@@ -448,6 +454,11 @@ extern void iommu_detach_pasid_table(struct iommu_domain *domain);
 extern int iommu_cache_invalidate(struct iommu_domain *domain,
 				  struct device *dev,
 				  struct iommu_cache_invalidate_info *inv_info);
+extern int iommu_bind_guest_msi(struct iommu_domain *domain,
+				dma_addr_t giova, phys_addr_t gpa, size_t size);
+extern void iommu_unbind_guest_msi(struct iommu_domain *domain,
+				   dma_addr_t giova);
+
 extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
 extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);
 extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
@@ -1000,6 +1011,15 @@ iommu_cache_invalidate(struct iommu_domain *domain,
 	return -ENODEV;
 }
 
+static inline
+int iommu_bind_guest_msi(struct iommu_domain *domain,
+			 dma_addr_t giova, phys_addr_t gpa, size_t size)
+{
+	return -ENODEV;
+}
+static inline
+void iommu_unbind_guest_msi(struct iommu_domain *domain, dma_addr_t giova) {}
+
 #endif /* CONFIG_IOMMU_API */
 
 #ifdef CONFIG_IOMMU_DEBUGFS
-- 
2.20.1

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  parent reply index

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-26 16:09 [PATCH v8 00/29] SMMUv3 Nested Stage Setup Eric Auger
2019-05-26 16:09 ` [PATCH v8 01/29] driver core: Add per device iommu param Eric Auger
2019-05-26 16:09 ` [PATCH v8 02/29] iommu: Introduce device fault data Eric Auger
2019-05-26 16:09 ` [PATCH v8 03/29] iommu: Introduce device fault report API Eric Auger
2019-05-26 16:09 ` [PATCH v8 04/29] iommu: Add recoverable fault reporting Eric Auger
2019-06-03 22:31   ` Alex Williamson
2019-06-04 15:48     ` Jacob Pan
2019-05-26 16:09 ` [PATCH v8 05/29] iommu: Add a timeout parameter for PRQ response Eric Auger
2019-06-03 22:32   ` Alex Williamson
2019-06-04 10:52     ` Jean-Philippe Brucker
2019-06-04 15:50       ` Jacob Pan
2019-05-26 16:09 ` [PATCH v8 06/29] trace/iommu: Add sva trace events Eric Auger
2019-05-26 16:09 ` [PATCH v8 07/29] iommu: Use device fault trace event Eric Auger
2019-05-26 16:09 ` [PATCH v8 08/29] iommu: Introduce attach/detach_pasid_table API Eric Auger
2019-05-26 16:09 ` [PATCH v8 09/29] iommu: Introduce cache_invalidate API Eric Auger
2019-05-26 16:09 ` Eric Auger [this message]
2019-05-26 16:09 ` [PATCH v8 11/29] iommu/arm-smmu-v3: Maintain a SID->device structure Eric Auger
2019-05-26 16:09 ` [PATCH v8 12/29] iommu/smmuv3: Dynamically allocate s1_cfg and s2_cfg Eric Auger
2019-05-26 16:09 ` [PATCH v8 13/29] iommu/smmuv3: Get prepared for nested stage support Eric Auger
2019-05-26 16:09 ` [PATCH v8 14/29] iommu/smmuv3: Implement attach/detach_pasid_table Eric Auger
2019-05-26 16:09 ` [PATCH v8 15/29] iommu/smmuv3: Introduce __arm_smmu_tlb_inv_asid/s1_range_nosync Eric Auger
2019-05-26 16:09 ` [PATCH v8 16/29] iommu/smmuv3: Implement cache_invalidate Eric Auger
2019-05-26 16:09 ` [PATCH v8 17/29] dma-iommu: Implement NESTED_MSI cookie Eric Auger
2019-05-26 16:09 ` [PATCH v8 18/29] iommu/smmuv3: Nested mode single MSI doorbell per domain enforcement Eric Auger
2019-05-26 16:09 ` [PATCH v8 19/29] iommu/smmuv3: Enforce incompatibility between nested mode and HW MSI regions Eric Auger
2019-05-26 16:09 ` [PATCH v8 20/29] iommu/smmuv3: Implement bind/unbind_guest_msi Eric Auger
2019-05-26 16:09 ` [PATCH v8 21/29] iommu/smmuv3: Report non recoverable faults Eric Auger
2019-05-26 16:09 ` [PATCH v8 22/29] vfio: VFIO_IOMMU_ATTACH/DETACH_PASID_TABLE Eric Auger
2019-06-03 22:32   ` Alex Williamson
2019-05-26 16:09 ` [PATCH v8 23/29] vfio: VFIO_IOMMU_CACHE_INVALIDATE Eric Auger
2019-06-14 12:38   ` Liu, Yi L
2019-06-14 13:17     ` Auger Eric
2019-05-26 16:09 ` [PATCH v8 24/29] vfio: VFIO_IOMMU_BIND/UNBIND_MSI Eric Auger
2019-06-03 22:32   ` Alex Williamson
2019-06-07  8:30     ` Auger Eric
2019-05-26 16:10 ` [PATCH v8 25/29] vfio-pci: Add a new VFIO_REGION_TYPE_NESTED region type Eric Auger
2019-06-03 22:31   ` Alex Williamson
2019-06-07  8:28     ` Auger Eric
2019-06-07 12:47       ` Jean-Philippe Brucker
2019-06-07 16:29       ` Alex Williamson
2019-05-26 16:10 ` [PATCH v8 26/29] vfio-pci: Register an iommu fault handler Eric Auger
2019-06-03 22:31   ` Alex Williamson
2019-06-04 16:11     ` Auger Eric
2019-06-05 22:45       ` Jacob Pan
2019-06-06 18:54         ` Jean-Philippe Brucker
2019-06-06 20:29           ` Jacob Pan
2019-06-07  7:02             ` Auger Eric
2019-06-07 10:28             ` Jean-Philippe Brucker
2019-06-07 17:43               ` Jacob Pan
2019-06-10 12:45                 ` Jean-Philippe Brucker
2019-06-10 21:31                   ` Jacob Pan
2019-06-11 13:14                     ` Jean-Philippe Brucker
2019-06-12 18:53                       ` Jacob Pan
2019-06-18 14:04                         ` Jean-Philippe Brucker
2019-06-19  0:19                           ` Jacob Pan
2019-06-19 11:44                             ` Jean-Philippe Brucker
2019-07-11 13:07                           ` Auger Eric
2019-06-07 12:48   ` Jean-Philippe Brucker
2019-06-07 14:18     ` Auger Eric
2019-05-26 16:10 ` [PATCH v8 27/29] vfio_pci: Allow to mmap the fault queue Eric Auger
2019-05-26 16:10 ` [PATCH v8 28/29] vfio-pci: Add VFIO_PCI_DMA_FAULT_IRQ_INDEX Eric Auger
2019-06-03 22:31   ` Alex Williamson
2019-06-04 16:11     ` Auger Eric
2019-05-26 16:10 ` [PATCH v8 29/29] vfio: Document nested stage control Eric Auger

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