friedkiwi/qemu
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

whpx: i386: documentation update

Browse Source 
Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
Link: https://lore.kernel.org/r/20260422214225.2242-38-mohamed@unpredictable.fr
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Mohamed Mediouni
2026-04-22 23:42:25 +02:00
committed by Paolo Bonzini
parent a1a3692d15
commit f0eb0ef4d8
1 changed files with 11 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
docs/system/whpx.rst
View File

@@ -63,7 +63,7 @@ additional functionality compared to ``-device ramfb``, but is
incompatible with Windows's UEFI GOP implementation, which
expects a linear framebuffer to be available.
Some tracing options
Accelerator options
--------------------
x86_64
@@ -75,6 +75,11 @@ to undocumented MSRs.
``-d invalid_mem`` allows to trace accesses to unmapped
GPAs.
``-accel whpx,ssd=off`` disables the separate security domain feature,
as in a BTB flush when entering/exiting the guest. This results in a
significant MMIO performance increase at the detriment of security
mitigations.
Known issues on x86_64
----------------------
@@ -96,45 +101,22 @@ MMX, SSE or AVX instructions for access to MMIO memory ranges.
Attempts to run such guests will result in an ``Unimplemented handler``
warning for MMX and a failure to decode for newer instructions.
``-M isapc``
^^^^^^^^^^^^
``-M isapc`` doesn't disable the Hyper-V LAPIC on its own yet. To
be able to use that machine, use ``-accel whpx,hyperv=off,kernel-irqchip=off``.
However, in QEMU 11.0, the guest will still be a 64-bit x86
ISA machine with all the corresponding CPUID leaves exposed.
gdbstub
^^^^^^^
As save/restore of xsave state is not currently present, state
exposed through GDB will be incomplete.
The same also applies to ``info registers``.
``-cpu type`` ignored
^^^^^^^^^^^^^^^^^^^^^
In this release, -cpu is an ignored argument.
PIC interrupts on Windows 10
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
On Windows 10, a legacy PIC interrupt injected does not wake the guest
from an HLT when using the Hyper-V provided interrupt controller.
This has been addressed in QEMU 11.0 on Windows 11 platforms but
functionality to make it available on Windows 10 isn't present.
As such, on Windows 10, using the Hyper-V interrupt controller is
disabled by default. You can enable it via ``-M q35,pic=off`` which
disables the PIC. In that configuration, using a UEFI is recommended.
Workaround: for affected use cases, use ``-M kernel-irqchip=off``.
On this release, ``-M kernel-irqchip=`` is not expected to be manually
set during normal operation. It remains as a debugging option.
Known issues on Windows 11
^^^^^^^^^^^^^^^^^^^^^^^^^^
Nested virtualisation-specific Hyper-V enlightenments are not
currently exposed.
arm64
-----