€•ZA      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ(/translations/zh_CN/virt/acrn/io-request”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ(/translations/zh_TW/virt/acrn/io-request”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ(/translations/it_IT/virt/acrn/io-request”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ(/translations/ja_JP/virt/acrn/io-request”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ(/translations/ko_KR/virt/acrn/io-request”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ(/translations/pt_BR/virt/acrn/io-request”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ(/translations/sp_SP/virt/acrn/io-request”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒcomment”“”)”}”(hŒ SPDX-License-Identifier: GPL-2.0”h]”hŒ SPDX-License-Identifier: GPL-2.0”…””}”hh·sbah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1hµhhh²hh³ŒB/var/lib/git/docbuild/linux/Documentation/virt/acrn/io-request.rst”h´KubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒI/O request handling”h]”hŒI/O request handling”…””}”(hhÏh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhhÊh²hh³hÇh´KubhŒ	paragraph”“”)”}”(hX
  An I/O request of a User VM, which is constructed by the hypervisor, is
distributed by the ACRN Hypervisor Service Module to an I/O client
corresponding to the address range of the I/O request. Details of I/O request
handling are described in the following sections.”h]”hX
  An I/O request of a User VM, which is constructed by the hypervisor, is
distributed by the ACRN Hypervisor Service Module to an I/O client
corresponding to the address range of the I/O request. Details of I/O request
handling are described in the following sections.”…””}”(hhßh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KhhÊh²hubhÉ)”}”(hhh]”(hÎ)”}”(hŒ1. I/O request”h]”hŒ1. I/O request”…””}”(hhðh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhhíh²hh³hÇh´KubhÞ)”}”(hXK  For each User VM, there is a shared 4-KByte memory region used for I/O requests
communication between the hypervisor and Service VM. An I/O request is a
256-byte structure buffer, which is 'struct acrn_io_request', that is filled by
an I/O handler of the hypervisor when a trapped I/O access happens in a User
VM. ACRN userspace in the Service VM first allocates a 4-KByte page and passes
the GPA (Guest Physical Address) of the buffer to the hypervisor. The buffer is
used as an array of 16 I/O request slots with each I/O request slot being 256
bytes. This array is indexed by vCPU ID.”h]”hXO  For each User VM, there is a shared 4-KByte memory region used for I/O requests
communication between the hypervisor and Service VM. An I/O request is a
256-byte structure buffer, which is â€˜struct acrn_io_requestâ€™, that is filled by
an I/O handler of the hypervisor when a trapped I/O access happens in a User
VM. ACRN userspace in the Service VM first allocates a 4-KByte page and passes
the GPA (Guest Physical Address) of the buffer to the hypervisor. The buffer is
used as an array of 16 I/O request slots with each I/O request slot being 256
bytes. This array is indexed by vCPU ID.”…””}”(hhþh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Khhíh²hubeh}”(h]”Œi-o-request”ah ]”h"]”Œ1. i/o request”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´KubhÉ)”}”(hhh]”(hÎ)”}”(hŒ2. I/O clients”h]”hŒ2. I/O clients”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj  h²hh³hÇh´KubhÞ)”}”(hX‹  An I/O client is responsible for handling User VM I/O requests whose accessed
GPA falls in a certain range. Multiple I/O clients can be associated with each
User VM. There is a special client associated with each User VM, called the
default client, that handles all I/O requests that do not fit into the range of
any other clients. The ACRN userspace acts as the default client for each User
VM.”h]”hX‹  An I/O client is responsible for handling User VM I/O requests whose accessed
GPA falls in a certain range. Multiple I/O clients can be associated with each
User VM. There is a special client associated with each User VM, called the
default client, that handles all I/O requests that do not fit into the range of
any other clients. The ACRN userspace acts as the default client for each User
VM.”…””}”(hj%  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Khj  h²hubhÞ)”}”(hŒkBelow illustration shows the relationship between I/O requests shared buffer,
I/O requests and I/O clients.”h]”hŒkBelow illustration shows the relationship between I/O requests shared buffer,
I/O requests and I/O clients.”…””}”(hj3  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K!hj  h²hubhŒliteral_block”“”)”}”(hX	  +------------------------------------------------------+
|                                       Service VM     |
|+--------------------------------------------------+  |
||      +----------------------------------------+  |  |
||      | shared page            ACRN userspace  |  |  |
||      |    +-----------------+  +------------+ |  |  |
||   +----+->| acrn_io_request |<-+  default   | |  |  |
||   |  | |  +-----------------+  | I/O client | |  |  |
||   |  | |  |       ...       |  +------------+ |  |  |
||   |  | |  +-----------------+                 |  |  |
||   |  +-|--------------------------------------+  |  |
||---|----|-----------------------------------------|  |
||   |    |                             kernel      |  |
||   |    |            +----------------------+     |  |
||   |    |            | +-------------+  HSM |     |  |
||   |    +--------------+             |      |     |  |
||   |                 | | I/O clients |      |     |  |
||   |                 | |             |      |     |  |
||   |                 | +-------------+      |     |  |
||   |                 +----------------------+     |  |
|+---|----------------------------------------------+  |
+----|-------------------------------------------------+
     |
+----|-------------------------------------------------+
|  +-+-----------+                                     |
|  | I/O handler |              ACRN Hypervisor        |
|  +-------------+                                     |
+------------------------------------------------------+”h]”hX	  +------------------------------------------------------+
|                                       Service VM     |
|+--------------------------------------------------+  |
||      +----------------------------------------+  |  |
||      | shared page            ACRN userspace  |  |  |
||      |    +-----------------+  +------------+ |  |  |
||   +----+->| acrn_io_request |<-+  default   | |  |  |
||   |  | |  +-----------------+  | I/O client | |  |  |
||   |  | |  |       ...       |  +------------+ |  |  |
||   |  | |  +-----------------+                 |  |  |
||   |  +-|--------------------------------------+  |  |
||---|----|-----------------------------------------|  |
||   |    |                             kernel      |  |
||   |    |            +----------------------+     |  |
||   |    |            | +-------------+  HSM |     |  |
||   |    +--------------+             |      |     |  |
||   |                 | | I/O clients |      |     |  |
||   |                 | |             |      |     |  |
||   |                 | +-------------+      |     |  |
||   |                 +----------------------+     |  |
|+---|----------------------------------------------+  |
+----|-------------------------------------------------+
     |
+----|-------------------------------------------------+
|  +-+-----------+                                     |
|  | I/O handler |              ACRN Hypervisor        |
|  +-------------+                                     |
+------------------------------------------------------+”…””}”hjC  sbah}”(h]”h ]”h"]”h$]”h&]”hÅhÆuh1jA  h³hÇh´K&hj  h²hubeh}”(h]”Œi-o-clients”ah ]”h"]”Œ2. i/o clients”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´KubhÉ)”}”(hhh]”(hÎ)”}”(hŒ3. I/O request state transition”h]”hŒ3. I/O request state transition”…””}”(hj\  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjY  h²hh³hÇh´KDubhÞ)”}”(hŒ<The state transitions of an ACRN I/O request are as follows.”h]”hŒ<The state transitions of an ACRN I/O request are as follows.”…””}”(hjj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KFhjY  h²hubjB  )”}”(hŒ8FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ...”h]”hŒ8FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ...”…””}”hjx  sbah}”(h]”h ]”h"]”h$]”h&]”hÅhÆuh1jA  h³hÇh´KJhjY  h²hubhŒbullet_list”“”)”}”(hhh]”(hŒ	list_item”“”)”}”(hŒ$FREE: this I/O request slot is empty”h]”hÞ)”}”(hj  h]”hŒ$FREE: this I/O request slot is empty”…””}”(hj‘  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KLhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hjˆ  h²hh³hÇh´NubjŒ  )”}”(hŒ4PENDING: a valid I/O request is pending in this slot”h]”hÞ)”}”(hj¦  h]”hŒ4PENDING: a valid I/O request is pending in this slot”…””}”(hj¨  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KMhj¤  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hjˆ  h²hh³hÇh´NubjŒ  )”}”(hŒ.PROCESSING: the I/O request is being processed”h]”hÞ)”}”(hj½  h]”hŒ.PROCESSING: the I/O request is being processed”…””}”(hj¿  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KNhj»  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hjˆ  h²hh³hÇh´NubjŒ  )”}”(hŒ-COMPLETE: the I/O request has been processed
”h]”hÞ)”}”(hŒ,COMPLETE: the I/O request has been processed”h]”hŒ,COMPLETE: the I/O request has been processed”…””}”(hjÖ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KOhjÒ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hjˆ  h²hh³hÇh´Nubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ-”uh1j†  h³hÇh´KLhjY  h²hubhÞ)”}”(hŒƒAn I/O request in COMPLETE or FREE state is owned by the hypervisor. HSM and
ACRN userspace are in charge of processing the others.”h]”hŒƒAn I/O request in COMPLETE or FREE state is owned by the hypervisor. HSM and
ACRN userspace are in charge of processing the others.”…””}”(hjò  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KQhjY  h²hubeh}”(h]”Œi-o-request-state-transition”ah ]”h"]”Œ3. i/o request state transition”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´KDubhÉ)”}”(hhh]”(hÎ)”}”(hŒ"4. Processing flow of I/O requests”h]”hŒ"4. Processing flow of I/O requests”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj  h²hh³hÇh´KUubhŒenumerated_list”“”)”}”(hhh]”(jŒ  )”}”(hŒ}The I/O handler of the hypervisor will fill an I/O request with PENDING
state when a trapped I/O access happens in a User VM.”h]”hÞ)”}”(hŒ}The I/O handler of the hypervisor will fill an I/O request with PENDING
state when a trapped I/O access happens in a User VM.”h]”hŒ}The I/O handler of the hypervisor will fill an I/O request with PENDING
state when a trapped I/O access happens in a User VM.”…””}”(hj"  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KWhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hj  h²hh³hÇh´NubjŒ  )”}”(hŒUThe hypervisor makes an upcall, which is a notification interrupt, to
the Service VM.”h]”hÞ)”}”(hŒUThe hypervisor makes an upcall, which is a notification interrupt, to
the Service VM.”h]”hŒUThe hypervisor makes an upcall, which is a notification interrupt, to
the Service VM.”…””}”(hj:  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KYhj6  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hj  h²hh³hÇh´NubjŒ  )”}”(hŒ?The upcall handler schedules a worker to dispatch I/O requests.”h]”hÞ)”}”(hjP  h]”hŒ?The upcall handler schedules a worker to dispatch I/O requests.”…””}”(hjR  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K[hjN  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hj  h²hh³hÇh´NubjŒ  )”}”(hŒÙThe worker looks for the PENDING I/O requests, assigns them to different
registered clients based on the address of the I/O accesses, updates
their state to PROCESSING, and notifies the corresponding client to handle.”h]”hÞ)”}”(hŒÙThe worker looks for the PENDING I/O requests, assigns them to different
registered clients based on the address of the I/O accesses, updates
their state to PROCESSING, and notifies the corresponding client to handle.”h]”hŒÙThe worker looks for the PENDING I/O requests, assigns them to different
registered clients based on the address of the I/O accesses, updates
their state to PROCESSING, and notifies the corresponding client to handle.”…””}”(hji  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K\hje  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hj  h²hh³hÇh´NubjŒ  )”}”(hŒ6The notified client handles the assigned I/O requests.”h]”hÞ)”}”(hj  h]”hŒ6The notified client handles the assigned I/O requests.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K_hj}  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hj  h²hh³hÇh´NubjŒ  )”}”(hŒmThe HSM updates I/O requests states to COMPLETE and notifies the hypervisor
of the completion via hypercalls.”h]”hÞ)”}”(hŒmThe HSM updates I/O requests states to COMPLETE and notifies the hypervisor
of the completion via hypercalls.”h]”hŒmThe HSM updates I/O requests states to COMPLETE and notifies the hypervisor
of the completion via hypercalls.”…””}”(hj˜  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K`hj”  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j‹  hj  h²hh³hÇh´Nubeh}”(h]”h ]”h"]”h$]”h&]”Œenumtype”Œ
loweralpha”Œprefix”hŒsuffix”Œ.”uh1j  hj  h²hh³hÇh´KWubeh}”(h]”Œprocessing-flow-of-i-o-requests”ah ]”h"]”Œ"4. processing flow of i/o requests”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´KUubeh}”(h]”Œi-o-request-handling”ah ]”h"]”Œi/o request handling”ah$]”h&]”uh1hÈhhh²hh³hÇh´Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”hÇuh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(hÍNŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jê  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”hÇŒ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jÄ  jÁ  j  j  jV  jS  j  j  j¼  j¹  uŒ	nametypes”}”(jÄ  ‰j  ‰jV  ‰j  ‰j¼  ‰uh}”(jÁ  hÊj  híjS  j  j  jY  j¹  j  uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
decoration”Nh²hub.