6 files changed, 171 insertions, 3 deletions
diff --git a/docs/specs/index.rst b/docs/specs/index.rst
index ff5a1f03da..d7675cebc2 100644
--- a/docs/specs/index.rst
+++ b/docs/specs/index.rst
@@ -37,3 +37,4 @@ guest hardware that is specific to QEMU.
    rapl-msr
    rocker
    riscv-iommu
+   riscv-aia
diff --git a/docs/specs/riscv-aia.rst b/docs/specs/riscv-aia.rst
new file mode 100644
index 0000000000..8097e2f897
--- /dev/null
+++ b/docs/specs/riscv-aia.rst
@@ -0,0 +1,83 @@
+.. _riscv-aia:
+
+RISC-V AIA support for RISC-V machines
+======================================
+
+AIA (Advanced Interrupt Architecture) support is implemented in the ``virt``
+RISC-V machine for TCG and KVM accelerators.
+
+The support consists of two main modes:
+
+- "aia=aplic": adds one or more APLIC (Advanced Platform Level Interrupt Controller)
+  devices
+- "aia=aplic-imsic": adds one or more APLIC device and an IMSIC (Incoming MSI
+   Controller) device for each CPU
+
+From an user standpoint, these modes will behave the same regardless of the accelerator
+used.  From a developer standpoint the accelerator settings will change what it being
+emulated in userspace versus what is being emulated by an in-kernel irqchip.
+
+When running TCG, all controllers are emulated in userspace, including machine mode
+(m-mode) APLIC and IMSIC (when applicable).
+
+When running KVM:
+
+- no m-mode is provided, so there is no m-mode APLIC or IMSIC emulation regardless of
+  the AIA mode chosen
+- with "aia=aplic", s-mode APLIC will be emulated by userspace
+- with "aia=aplic-imsic" there are two possibilities.  If no additional KVM option
+  is provided there will be no APLIC or IMSIC emulation in userspace, and the virtual
+  machine will use the provided in-kernel APLIC and IMSIC controllers.  If the user
+  chooses to use the irqchip in split mode via "-accel kvm,kernel-irqchip=split",
+  s-mode APLIC will be emulated while using the s-mode IMSIC from the irqchip
+
+The following table summarizes how the AIA and accelerator options defines what
+we will emulate in userspace:
+
+
+.. list-table:: How AIA and accel options changes controller emulation
+   :widths: 25 25 25 25 25 25 25
+   :header-rows: 1
+
+   * - Accel
+     - Accel props
+     - AIA type
+     - APLIC m-mode
+     - IMSIC m-mode
+     - APLIC s-mode
+     - IMSIC s-mode
+   * - tcg
+     - ---
+     - aplic
+     - emul
+     - n/a
+     - emul
+     - n/a
+   * - tcg
+     - ---
+     - aplic-imsic
+     - emul
+     - emul
+     - emul
+     - emul
+   * - kvm
+     - ---
+     - aplic
+     - n/a
+     - n/a
+     - emul
+     - n/a
+   * - kvm
+     - none
+     - aplic-imsic
+     - n/a
+     - n/a
+     - in-kernel
+     - in-kernel
+   * - kvm
+     - irqchip=split
+     - aplic-imsic
+     - n/a
+     - n/a
+     - emul
+     - in-kernel
diff --git a/docs/specs/riscv-iommu.rst b/docs/specs/riscv-iommu.rst
index 463f4cffb6..b1538c9ead 100644
--- a/docs/specs/riscv-iommu.rst
+++ b/docs/specs/riscv-iommu.rst
@@ -6,9 +6,9 @@ RISC-V IOMMU support for RISC-V machines
 QEMU implements a RISC-V IOMMU emulation based on the RISC-V IOMMU spec
 version 1.0 `iommu1.0`_.
 
-The emulation includes a PCI reference device, riscv-iommu-pci, that QEMU
-RISC-V boards can use.  The 'virt' RISC-V machine is compatible with this
-device.
+The emulation includes a PCI reference device (riscv-iommu-pci) and a platform
+bus device (riscv-iommu-sys) that QEMU RISC-V boards can use.  The 'virt'
+RISC-V machine is compatible with both devices.
 
 riscv-iommu-pci reference device
 --------------------------------
@@ -83,6 +83,30 @@ Several options are available to control the capabilities of the device, namely:
 - "s-stage": enable s-stage support
 - "g-stage": enable g-stage support
 
+riscv-iommu-sys device
+----------------------
+
+This device implements the RISC-V IOMMU emulation as a platform bus device that
+RISC-V boards can use.
+
+For the 'virt' board the device is disabled by default.  To enable it use the
+'iommu-sys' machine option:
+
+.. code-block:: bash
+
+  $ qemu-system-riscv64 -M virt,iommu-sys=on (...)
+
+There is no options to configure the capabilities of this device in the 'virt'
+board using the QEMU command line.  The device is configured with the following
+riscv-iommu options:
+
+- "ioatc-limit": default value (2Mb)
+- "intremap": enabled
+- "ats": enabled
+- "off": on (DMA disabled)
+- "s-stage": enabled
+- "g-stage": enabled
+
 .. _iommu1.0: https://github.com/riscv-non-isa/riscv-iommu/releases/download/v1.0/riscv-iommu.pdf
 
 .. _linux-v8: https://lore.kernel.org/linux-riscv/cover.1718388908.git.tjeznach@rivosinc.com/
diff --git a/docs/system/riscv/microblaze-v-generic.rst b/docs/system/riscv/microblaze-v-generic.rst
new file mode 100644
index 0000000000..5606f88d57
--- /dev/null
+++ b/docs/system/riscv/microblaze-v-generic.rst
@@ -0,0 +1,42 @@
+Microblaze-V generic board (``amd-microblaze-v-generic``)
+=========================================================
+The AMD MicroBlaze™ V processor is a soft-core RISC-V processor IP for AMD
+adaptive SoCs and FPGAs. The MicroBlaze™ V processor is based on the 32-bit (or
+64-bit) RISC-V instruction set architecture (ISA) and contains interfaces
+compatible with the classic MicroBlaze™ V processor (i.e it is a drop in
+replacement for the classic MicroBlaze™ processor in existing RTL designs).
+More information can be found in below document.
+
+https://docs.amd.com/r/en-US/ug1629-microblaze-v-user-guide/MicroBlaze-V-Architecture
+
+The MicroBlaze™ V generic board in QEMU has following supported devices:
+
+    - timer
+    - uartlite
+    - uart16550
+    - emaclite
+    - timer2
+    - axi emac
+    - axi dma
+
+The MicroBlaze™ V core in QEMU has the following configuration:
+
+    - RV32I base integer instruction set
+    - "Zicsr" Control and Status register instructions
+    - "Zifencei" instruction-fetch
+    - Extensions: m, a, f, c
+
+Running
+"""""""
+Below is an example command line for launching mainline U-boot
+(xilinx_mbv32_defconfig) on the Microblaze-V generic board.
+
+.. code-block:: bash
+
+   $ qemu-system-riscv32 -M amd-microblaze-v-generic \
+     -display none \
+     -device loader,addr=0x80000000,file=u-boot-spl.bin,cpu-num=0 \
+     -device loader,addr=0x80200000,file=u-boot.img \
+     -serial mon:stdio \
+     -device loader,addr=0x83000000,file=system.dtb \
+     -m 2g
diff --git a/docs/system/riscv/virt.rst b/docs/system/riscv/virt.rst
index 8e9a2e4dda..60850970ce 100644
--- a/docs/system/riscv/virt.rst
+++ b/docs/system/riscv/virt.rst
@@ -94,6 +94,12 @@ command line:
 
   $ qemu-system-riscv64 -M virt -device riscv-iommu-pci (...)
 
+It also has support for the riscv-iommu-sys platform device:
+
+.. code-block:: bash
+
+  $ qemu-system-riscv64 -M virt,iommu-sys=on (...)
+
 Refer to :ref:`riscv-iommu` for more information on how the RISC-V IOMMU support
 works.
 
@@ -123,12 +129,23 @@ The following machine-specific options are supported:
   MSIs. When not specified, this option is assumed to be "none" which selects
   SiFive PLIC to handle wired interrupts.
 
+  This option also interacts with '-accel kvm'.  When using "aia=aplic-imsic"
+  with KVM, it is possible to set the use of the kernel irqchip in split mode
+  by using "-accel kvm,kernel-irqchip=split".  In this case the ``virt`` machine
+  will emulate the APLIC controller instead of using the APLIC controller from
+  the irqchip.  See :ref:`riscv-aia` for more details on all available AIA
+  modes.
+
 - aia-guests=nnn
 
   The number of per-HART VS-level AIA IMSIC pages to be emulated for a guest
   having AIA IMSIC (i.e. "aia=aplic-imsic" selected). When not specified,
   the default number of per-HART VS-level AIA IMSIC pages is 0.
 
+- iommu-sys=[on|off]
+
+  Enables the riscv-iommu-sys platform device. Defaults to 'off'.
+
 Running Linux kernel
 --------------------
 
diff --git a/docs/system/target-riscv.rst b/docs/system/target-riscv.rst
index ba195f1518..95457af130 100644
--- a/docs/system/target-riscv.rst
+++ b/docs/system/target-riscv.rst
@@ -66,6 +66,7 @@ undocumented; you can get a complete list by running
 .. toctree::
    :maxdepth: 1
 
+   riscv/microblaze-v-generic
    riscv/microchip-icicle-kit
    riscv/shakti-c
    riscv/sifive_u