Messages in this thread | | | Date | Fri, 20 Mar 2020 23:21:02 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 62/70] x86/kvm: Add KVM specific VMMCALL handling under SEV-ES |
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On Fri, Mar 20, 2020 at 02:23:58PM -0700, David Rientjes wrote: > On Thu, 19 Mar 2020, Joerg Roedel wrote: > > +#if defined(CONFIG_AMD_MEM_ENCRYPT) > > +static void kvm_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs) > > +{ > > + /* RAX and CPL are already in the GHCB */ > > + ghcb_set_rbx(ghcb, regs->bx); > > + ghcb_set_rcx(ghcb, regs->cx); > > + ghcb_set_rdx(ghcb, regs->dx); > > + ghcb_set_rsi(ghcb, regs->si); > > Is it possible to check the hypercall from RAX and only copy the needed > regs or is there a requirement that they must all be copied > unconditionally?
No, there is no such requirement. This could be optimized with hypercall specific knowledge as it is in the KVM code anyway.
Regards,
Joerg
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