Re: [PATCH v2 0/4] Add support for updated vmware hypercall instruction

From: Thomas HellstrÃm (VMware)
Date: Tue Aug 27 2019 - 04:33:29 EST


Thomas,

On 8/23/19 10:13 AM, Thomas HellstrÃm (VMware) wrote:
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: <x86@xxxxxxxxxx>

VMware has started using "vmcall" / "vmmcall" instead of an inl instruction
for the "backdoor" interface. This series detects support for those
instructions.
Outside of the platform code we use the "ALTERNATIVES" self-patching
mechanism similarly to how this is done with KVM.
Unfortunately we need two new x86 CPU feature flags for this, since we need
the default instruction to be "inl". IIRC the vmmouse driver is used by
other virtualization solutions than VMware, and those might break if
they encounter any of the other instructions.

v2:
- Address various style review comments
- Use mnemonics instead of bytecode in the ALTERNATIVE_2 macros
- Use vmcall / vmmcall also for the High-Bandwidth port calls
- Change the %edx argument to what vmcall / vmmcall expect (flags instead of
port number). The port number is added in the default ALTERNATIVE_2 path.
- Ack to merge the vmmouse patch from Dmitry.
- Drop license update for now. Will get back with a freestanding patch.
Are you OK taking the above series through the x86 tree? In addition to the ack from Dmitry to do this for the vmmouse patch, there's also an ack from Dave to do the same for vmwgfx.

Thanks,
Thomas