Messages in this thread | | | Date | Thu, 27 Oct 2022 17:03:08 +0200 | Subject | Re: [PATCH v2 03/16] KVM: x86: Always use non-compat vcpu_runstate_info size for gfn=>pfn cache | From | Paolo Bonzini <> |
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On 10/27/22 16:44, Sean Christopherson wrote: >> - long mode cannot be changed after the shared info page is enabled (which >> makes sense because the shared info page also has a compat version) > > How is this not introducing an additional restriction? This seems way more > onerous than what is effectively a revert. > >> - the caches must be activated after the shared info page (which enforces >> that the vCPU attributes are set after the VM attributes) >> >> This is technically a userspace API break, but nobody is really using this >> API outside Amazon so... Patches coming after I finish testing. > > It's not just userspace break, it affects the guest ABI as well.
Yes, I was talking of the VMM here; additional restrictions are fine there.
The guests however should be compatible with Xen, so you also need to re-activate the cache after the hypercall page is written, but that's two lines of code.
Paolo
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