RE: [PATCH 1/4] x86/hyperv: Move VMCB enlightenment definitions to hyperv-tlfs.h

[Michael Kelley (LINUX)]

From: Sean Christopherson <seanjc@xxxxxxxxxx> Sent: Wednesday, September 21, 2022 1:16 PM
> 
> Move Hyper-V's VMCB enlightenment definitions to the TLFS header; the
> definitions come directly from the TLFS[*], not from KVM.
> 
> No functional change intended.
> 
> [*] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/datatypes/hv_svm_enlightened_vmcb_fields> 
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
>  arch/x86/include/asm/hyperv-tlfs.h | 22 +++++++++++++++++++
>  arch/x86/kvm/svm/hyperv.h          | 35 ------------------------------
>  arch/x86/kvm/svm/svm_onhyperv.h    |  3 ++-
>  3 files changed, 24 insertions(+), 36 deletions(-)
>  delete mode 100644 arch/x86/kvm/svm/hyperv.h
> 
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index 0a9407dc0859..4c4f81daf5a2 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -584,6 +584,28 @@ struct hv_enlightened_vmcs {
> 
>  #define HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL			0xFFFF
> 
> +/*
> + * Hyper-V uses the software reserved 32 bytes in VMCB control area to expose
> + * SVM enlightenments to guests.
> + */
> +struct hv_enlightenments {
> +	struct __packed hv_enlightenments_control {
> +		u32 nested_flush_hypercall:1;
> +		u32 msr_bitmap:1;
> +		u32 enlightened_npt_tlb: 1;
> +		u32 reserved:29;
> +	} __packed hv_enlightenments_control;
> +	u32 hv_vp_id;
> +	u64 hv_vm_id;
> +	u64 partition_assist_page;
> +	u64 reserved;
> +} __packed;
> +
> +/*
> + * Hyper-V uses the software reserved clean bit in VMCB.
> + */
> +#define VMCB_HV_NESTED_ENLIGHTENMENTS		31

Is it feasible to change this identifier so it starts with HV_ like
everything else in this source code file, such as
HV_VMCB_NESTED_ENLIGHTENMENTS?  It doesn't look like it is
used in very many places.  

> +
>  struct hv_partition_assist_pg {
>  	u32 tlb_lock_count;
>  };
> diff --git a/arch/x86/kvm/svm/hyperv.h b/arch/x86/kvm/svm/hyperv.h
> deleted file mode 100644
> index 7d6d97968fb9..000000000000
> --- a/arch/x86/kvm/svm/hyperv.h
> +++ /dev/null
> @@ -1,35 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0-only */
> -/*
> - * Common Hyper-V on KVM and KVM on Hyper-V definitions (SVM).
> - */
> -
> -#ifndef __ARCH_X86_KVM_SVM_HYPERV_H__
> -#define __ARCH_X86_KVM_SVM_HYPERV_H__
> -
> -#include <asm/mshyperv.h>
> -
> -#include "../hyperv.h"
> -
> -/*
> - * Hyper-V uses the software reserved 32 bytes in VMCB
> - * control area to expose SVM enlightenments to guests.
> - */
> -struct hv_enlightenments {
> -	struct __packed hv_enlightenments_control {
> -		u32 nested_flush_hypercall:1;
> -		u32 msr_bitmap:1;
> -		u32 enlightened_npt_tlb: 1;
> -		u32 reserved:29;
> -	} __packed hv_enlightenments_control;
> -	u32 hv_vp_id;
> -	u64 hv_vm_id;
> -	u64 partition_assist_page;
> -	u64 reserved;
> -} __packed;
> -
> -/*
> - * Hyper-V uses the software reserved clean bit in VMCB
> - */
> -#define VMCB_HV_NESTED_ENLIGHTENMENTS VMCB_SW
> -
> -#endif /* __ARCH_X86_KVM_SVM_HYPERV_H__ */
> diff --git a/arch/x86/kvm/svm/svm_onhyperv.h
> b/arch/x86/kvm/svm/svm_onhyperv.h
> index e2fc59380465..8d02654ad6f8 100644
> --- a/arch/x86/kvm/svm/svm_onhyperv.h
> +++ b/arch/x86/kvm/svm/svm_onhyperv.h
> @@ -8,8 +8,9 @@
> 
>  #if IS_ENABLED(CONFIG_HYPERV)
> 
> +#include <asm/mshyperv.h>
> +
>  #include "kvm_onhyperv.h"
> -#include "svm/hyperv.h"
> 
>  static struct kvm_x86_ops svm_x86_ops;
> 
> --
> 2.37.3.968.ga6b4b080e4-goog