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

[Siddharth Chandrasekaran]

On Tue, Jul 06, 2021 at 05:04:59PM +0200, Paolo Bonzini wrote:
> 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. :)

Ahh, I see them now. I was expecting them to show up in master - that was
the confusion.

Thanks! :)

~ Sid



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