diff options
Diffstat (limited to 'docs/about')
| -rw-r--r-- | docs/about/deprecated.rst | 34 | ||||
| -rw-r--r-- | docs/about/removed-features.rst | 9 |
2 files changed, 41 insertions, 2 deletions
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index e2b4f07..0538144 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -292,6 +292,36 @@ Big-Endian variants of MicroBlaze ``petalogix-ml605`` and ``xlnx-zynqmp-pmu`` ma Both ``petalogix-ml605`` and ``xlnx-zynqmp-pmu`` were added for little endian CPUs. Big endian support is not tested. +Mips ``mipssim`` machine (since 10.0) +''''''''''''''''''''''''''''''''''''' + +Linux dropped support for this virtual machine type in kernel v3.7, and +there does not seem to be anybody around who is still using this board +in QEMU: Most former MIPS-related people are working on other architectures +in their everyday job nowadays, and we are also not aware of anybody still +using old binaries with this board (i.e. there is also no binary available +online to check that this board did not completely bitrot yet). It is +recommended to use another MIPS machine for future MIPS code development +instead. + +RISC-V default machine option (since 10.0) +'''''''''''''''''''''''''''''''''''''''''' + +RISC-V defines ``spike`` as the default machine if no machine option is +given in the command line. This happens because ``spike`` is the first +RISC-V machine implemented in QEMU and setting it as default was +convenient at that time. Now we have 7 riscv64 and 6 riscv32 machines +and having ``spike`` as a default is no longer justified. This default +will also promote situations where users think they're running ``virt`` +(the most used RISC-V machine type in 10.0) when in fact they're +running ``spike``. + +Removing the default machine option forces users to always set the machine +they want to use and avoids confusion. Existing users of the ``spike`` +machine must ensure that they're setting the ``spike`` machine in the +command line (``-M spike``). + + Backend options --------------- @@ -422,7 +452,7 @@ Backend ``memory`` (since 9.0) ``reconnect`` (since 9.2) ^^^^^^^^^^^^^^^^^^^^^^^^^ -The ``reconnect`` option only allows specifiying second granularity timeouts, +The ``reconnect`` option only allows specifying second granularity timeouts, which is not enough for all types of use cases, use ``reconnect-ms`` instead. @@ -432,7 +462,7 @@ Net device options Stream ``reconnect`` (since 9.2) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -The ``reconnect`` option only allows specifiying second granularity timeouts, +The ``reconnect`` option only allows specifying second granularity timeouts, which is not enough for all types of use cases, use ``reconnect-ms`` instead. VFIO device options diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst index 2527a91..790a5e4 100644 --- a/docs/about/removed-features.rst +++ b/docs/about/removed-features.rst @@ -858,6 +858,15 @@ QEMU. Since all recent x86 hardware from the past >10 years is capable of the 64-bit x86 extensions, a corresponding 64-bit OS should be used instead. +32-bit hosts for 64-bit guests (removed in 10.0) +'''''''''''''''''''''''''''''''''''''''''''''''' + +In general, 32-bit hosts cannot support the memory space or atomicity +requirements of 64-bit guests. Prior to 10.0, QEMU attempted to +work around the atomicity issues in system mode by running all vCPUs +in a single thread context; in user mode atomicity was simply broken. +From 10.0, QEMU has disabled configuration of 64-bit guests on 32-bit hosts. + Guest Emulator ISAs ------------------- |