Re: [PATCH v4 0/4] Add support for XMM fast hypercalls

[Paolo Bonzini]

On 30/06/21 13:56, Siddharth Chandrasekaran wrote:
> On Wed, May 26, 2021 at 10:56:07AM +0200, Siddharth Chandrasekaran wrote:
> > Hyper-V supports the use of XMM registers to perform fast hypercalls.
> > This allows guests to take advantage of the improved performance of the
> > fast hypercall interface even though a hypercall may require more than
> > (the current maximum of) two general purpose registers.
> >
> > The XMM fast hypercall interface uses an additional six XMM registers
> > (XMM0 to XMM5) to allow the caller to pass an input parameter block of
> > up to 112 bytes. Hyper-V can also return data back to the guest in the
> > remaining XMM registers that are not used by the current hypercall.
> >
> > Although the Hyper-v TLFS mentions that a guest cannot use this feature
> > unless the hypervisor advertises support for it, some hypercalls which
> > we plan on upstreaming in future uses them anyway. This patchset adds
> > necessary infrastructure for handling input/output via XMM registers and
> > patches kvm_hv_flush_tlb() to use xmm input arguments.
>
> Hi Paolo,
>
> Are you expecting more reviews on these patches?

They are part of 5.14 already. :)

Paolo