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authorPeter Maydell2018-01-19 11:17:20 +0100
committerPeter Maydell2018-01-19 11:17:20 +0100
commit3e5bdc6573edf0585e4085e6a4e349b135abf3b4 (patch)
treed5a30ac7e2374d362cc7a927665d1938ed1e03ba /docs
parentMerge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2018-01-17' into st... (diff)
parentvhost: remove assertion to prevent crash (diff)
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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 18 Jan 2018 20:41:03 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: (29 commits) vhost: remove assertion to prevent crash vhost-user: fix misaligned access to payload vhost-user: factor out msg head and payload tests: acpi: add comments to fetch_rsdt_referenced_tables/data->tables usage tests: acpi: rename test_acpi_tables()/test_dst_table() to reflect its usage tests: acpi: init table descriptor in test_dst_table() tests: acpi: move tested tables array allocation outside of test_acpi_dsdt_table() x86_iommu: check if machine has PCI bus x86_iommu: Move machine check to x86_iommu_realize() vhost-user-test: use init_virtio_dev in multiqueue test vhost-user-test: make features mask an init_virtio_dev() argument vhost-user-test: setup virtqueues in all tests vhost-user-test: extract read-guest-mem test from main loop vhost-user-test: fix features mask hw/acpi-build: Make next_base easy to follow ACPI/unit-test: Add a testcase for RAM allocation in numa node hw/pci-bridge: fix QEMU crash because of pcie-root-port intel-iommu: Extend address width to 48 bits intel-iommu: Redefine macros to enable supporting 48 bit address width vhost-user: fix multiple queue specification ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'docs')
-rw-r--r--docs/interop/vhost-user.txt59
1 files changed, 57 insertions, 2 deletions
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index d49444e037..9fcf48d611 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -119,6 +119,19 @@ Depending on the request type, payload can be:
- 3: IOTLB invalidate
- 4: IOTLB access fail
+ * Virtio device config space
+ -----------------------------------
+ | offset | size | flags | payload |
+ -----------------------------------
+
+ Offset: a 32-bit offset of virtio device's configuration space
+ Size: a 32-bit configuration space access size in bytes
+ Flags: a 32-bit value:
+ - 0: Vhost master messages used for writeable fields
+ - 1: Vhost master messages used for live migration
+ Payload: Size bytes array holding the contents of the virtio
+ device's configuration space
+
In QEMU the vhost-user message is implemented with the following struct:
typedef struct VhostUserMsg {
@@ -132,6 +145,7 @@ typedef struct VhostUserMsg {
VhostUserMemory memory;
VhostUserLog log;
struct vhost_iotlb_msg iotlb;
+ VhostUserConfig config;
};
} QEMU_PACKED VhostUserMsg;
@@ -214,8 +228,8 @@ Multiple queue is treated as a protocol extension, hence the slave has to
implement protocol features first. The multiple queues feature is supported
only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set.
-The max number of queues the slave supports can be queried with message
-VHOST_USER_GET_PROTOCOL_FEATURES. Master should stop when the number of
+The max number of queue pairs the slave supports can be queried with message
+VHOST_USER_GET_QUEUE_NUM. Master should stop when the number of
requested queues is bigger than that.
As all queues share one connection, the master uses a unique index for each
@@ -623,6 +637,32 @@ Master message types
and expect this message once (per VQ) during device configuration
(ie. before the master starts the VQ).
+ * VHOST_USER_GET_CONFIG
+
+ Id: 24
+ Equivalent ioctl: N/A
+ Master payload: virtio device config space
+ Slave payload: virtio device config space
+
+ Submitted by the vhost-user master to fetch the contents of the virtio
+ device configuration space, vhost-user slave's payload size MUST match
+ master's request, vhost-user slave uses zero length of payload to
+ indicate an error to vhost-user master. The vhost-user master may
+ cache the contents to avoid repeated VHOST_USER_GET_CONFIG calls.
+
+* VHOST_USER_SET_CONFIG
+
+ Id: 25
+ Equivalent ioctl: N/A
+ Master payload: virtio device config space
+ Slave payload: N/A
+
+ Submitted by the vhost-user master when the Guest changes the virtio
+ device configuration space and also can be used for live migration
+ on the destination host. The vhost-user slave must check the flags
+ field, and slaves MUST NOT accept SET_CONFIG for read-only
+ configuration space fields unless the live migration bit is set.
+
Slave message types
-------------------
@@ -641,6 +681,21 @@ Slave message types
This request should be send only when VIRTIO_F_IOMMU_PLATFORM feature
has been successfully negotiated.
+* VHOST_USER_SLAVE_CONFIG_CHANGE_MSG
+
+ Id: 2
+ Equivalent ioctl: N/A
+ Slave payload: N/A
+ Master payload: N/A
+
+ Vhost-user slave sends such messages to notify that the virtio device's
+ configuration space has changed, for those host devices which can support
+ such feature, host driver can send VHOST_USER_GET_CONFIG message to slave
+ to get the latest content. If VHOST_USER_PROTOCOL_F_REPLY_ACK is
+ negotiated, and slave set the VHOST_USER_NEED_REPLY flag, master must
+ respond with zero when operation is successfully completed, or non-zero
+ otherwise.
+
VHOST_USER_PROTOCOL_F_REPLY_ACK:
-------------------------------
The original vhost-user specification only demands replies for certain