Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pc, pci, virtio: features, fixes, cleanups

A bunch of fixes, cleanus and new features all over the place.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Thu 11 Jan 2018 20:04:57 GMT
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (23 commits)
  smbus: do not immediately complete commands
  dump-guest-memory.py: fix "You can't do that without a process to debug"
  virtio-pci: Don't force Subsystem Vendor ID = Vendor ID
  intel_iommu: fix error param in string
  intel_iommu: remove X86_IOMMU_PCI_DEVFN_MAX
  vhost-user: document memory accesses
  vhost-user: fix indentation in protocol specification
  hw/pci-host/xilinx: QOM'ify the AXI-PCIe host bridge
  hw/pci-host/piix: QOM'ify the IGD Passthrough host bridge
  tests/pxe-test: Add some extra tests
  tests/pxe-test: Test net booting over IPv6 in some cases
  tests/pxe-test: Use table of testcases rather than open-coding
  tests/pxe-test: Remove unnecessary special case test functions
  virtio_error: don't invoke status callbacks
  pci: Eliminate pci_find_primary_bus()
  pci: Eliminate redundant PCIDevice::bus pointer
  pci: Add pci_dev_bus_num() helper
  pci: Move bridge data structures from pci_bus.h to pci_bridge.h
  pci: Rename root bus initialization functions for clarity
  tests: add test to check VirtQueue object
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 32 insertions, 5 deletions

diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index 954771d..d49444e 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -53,8 +53,8 @@ Depending on the request type, payload can be:
 
  * A vring state description
    ---------------
-  | index | num |
-  ---------------
+   | index | num |
+   ---------------
 
    Index: a 32-bit index
    Num: a 32-bit number
@@ -66,11 +66,14 @@ Depending on the request type, payload can be:
 
    Index: a 32-bit vring index
    Flags: a 32-bit vring flags
-   Descriptor: a 64-bit user address of the vring descriptor table
-   Used: a 64-bit user address of the vring used ring
-   Available: a 64-bit user address of the vring available ring
+   Descriptor: a 64-bit ring address of the vring descriptor table
+   Used: a 64-bit ring address of the vring used ring
+   Available: a 64-bit ring address of the vring available ring
    Log: a 64-bit guest address for logging
 
+   Note that a ring address is an IOVA if VIRTIO_F_IOMMU_PLATFORM has been
+   negotiated.  Otherwise it is a user address.
+
  * Memory regions description
    ---------------------------------------------------
    | num regions | padding | region0 | ... | region7 |
@@ -273,6 +276,30 @@ Once the source has finished migration, rings will be stopped by
 the source. No further update must be done before rings are
 restarted.
 
+Memory access
+-------------
+
+The master sends a list of vhost memory regions to the slave using the
+VHOST_USER_SET_MEM_TABLE message.  Each region has two base addresses: a guest
+address and a user address.
+
+Messages contain guest addresses and/or user addresses to reference locations
+within the shared memory.  The mapping of these addresses works as follows.
+
+User addresses map to the vhost memory region containing that user address.
+
+When the VIRTIO_F_IOMMU_PLATFORM feature has not been negotiated:
+
+ * Guest addresses map to the vhost memory region containing that guest
+   address.
+
+When the VIRTIO_F_IOMMU_PLATFORM feature has been negotiated:
+
+ * Guest addresses are also called I/O virtual addresses (IOVAs).  They are
+   translated to user addresses via the IOTLB.
+
+ * The vhost memory region guest address is not used.
+
 IOMMU support
 -------------