Messages in this thread | | | From | "Wang, Wei W" <> | Subject | RE: [PATCH 16/19] kvm: x86: Introduce KVM_{G|S}ET_XSAVE2 ioctl | Date | Thu, 16 Dec 2021 08:25:54 +0000 |
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On Wednesday, December 15, 2021 9:43 PM, Paolo Bonzini wrote: > It's still easier to return the full size of the buffer from > KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2). It makes the userspace code a > bit easier.
OK. For the "full size" returned to userspace, would you prefer to directly use the value retrieved from guest CPUID(0xd), or get it from guest_fpu (i.e. fpstate->user_size)? (retrieved from CPUID will be the max size and should work fine as well)
> > I'm also thinking that I prefer KVM_GET_XSAVE2 to > KVM_ENABLE_CAP(KVM_CAP_XSAVE2), after all. Since it would be a > backwards-incompatible change to an _old_ ioctl (KVM_GET_XSAVE), I prefer > to limit the ways that userspace can shoot itself in the foot.
OK, we will use KVM_GET_XSAVE2.
Thanks, Wei
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