[PATCH 0/4] x86/hyperv: KVM: VMCB enlightenment cleanups

[PATCH 0/4] x86/hyperv: KVM: VMCB enlightenment cleanups

[Sean Christopherson]

Hyper-V folks, if the changes look ok I'd like to take this through the
KVM tree as Vitaly has an in-progress KVM series[*] that conflicts mightily
with these changes.

The main goal of this series it to clean up KVM's ugly casting of the
VMCB's software reserved field to the Hyper-V enlightenments struct,
e.g. replace a bunch of code that does:

	(struct hv_enlightenments *)vmcb->control.reserved_sw;

with:

	&vmcb->control.hv_enlightenments;

That cleanup is complicated slightly due the Hyper-V enlightenments
being "KVM private", versus the VMCB struct being "public", but that
itself is also a "bug".  The enlightenments come directly from the TLFS,
i.e. aren't KVM internal.  Moving the definition to hyperv-tlfs.h where
it belongs has the happy side effect of making the struct visible to
asm/svm.h.

Compile tested only, but the resulting kvm-amd.ko binary is identical
before and after the series.

[*] https://lore.kernel.org/all/20220921152436.3673454-1-vkuznets@redhat.com

Sean Christopherson (4):
  x86/hyperv: Move VMCB enlightenment definitions to hyperv-tlfs.h
  KVM: selftests: Move "struct hv_enlightenments" to x86_64/svm.h
  KVM: SVM: Add a proper field for Hyper-V VMCB enlightenments
  x86/hyperv: KVM: Rename "hv_enlightenments" to
    "hv_vmcb_enlightenments"

 arch/x86/include/asm/hyperv-tlfs.h            | 22 ++++++++++++
 arch/x86/include/asm/svm.h                    |  7 +++-
 arch/x86/kvm/svm/hyperv.h                     | 35 -------------------
 arch/x86/kvm/svm/nested.c                     |  9 +++--
 arch/x86/kvm/svm/svm.h                        |  5 ++-
 arch/x86/kvm/svm/svm_onhyperv.c               |  4 +--
 arch/x86/kvm/svm/svm_onhyperv.h               | 18 +++++-----
 .../selftests/kvm/include/x86_64/svm.h        | 22 +++++++++++-
 .../selftests/kvm/x86_64/hyperv_svm_test.c    | 21 +----------
 9 files changed, 69 insertions(+), 74 deletions(-)
 delete mode 100644 arch/x86/kvm/svm/hyperv.h


base-commit: 372d07084593dc7a399bf9bee815711b1fb1bcf2
-- 
2.37.3.968.ga6b4b080e4-goog

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

[Sean Christopherson]

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@google.com>
---
 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
+
 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

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

[Michael Kelley (LINUX)]

From: Sean Christopherson <seanjc@google.com> 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@google.com>
> ---
>  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

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

[Sean Christopherson]

On Thu, Sep 22, 2022, Michael Kelley (LINUX) wrote:
> From: Sean Christopherson <seanjc@google.com> 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@google.com>
> > ---
> >  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.  

Most definitely, IIRC it's used in only one spot.

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

[Vitaly Kuznetsov]

Sean Christopherson <seanjc@google.com> writes:

> On Thu, Sep 22, 2022, Michael Kelley (LINUX) wrote:
>> From: Sean Christopherson <seanjc@google.com> 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@google.com>
>> > ---
>> >  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.  
>
> Most definitely, IIRC it's used in only one spot.
>

I'll take these 4 patches to the next iteration of my "KVM: x86:
hyper-v: Fine-grained TLB flush + L2 TLB flush features" series and I'll
change VMCB_HV_NESTED_ENLIGHTENMENTS to HV_VMCB_NESTED_ENLIGHTENMENTS.

-- 
Vitaly

[PATCH 2/4] KVM: selftests: Move "struct hv_enlightenments" to x86_64/svm.h

[Sean Christopherson]

Move Hyper-V's VMCB "struct hv_enlightenments" to the svm.h header so
that the struct can be referenced in "struct vmcb_control_area".
Alternatively, a dedicated header for SVM+Hyper-V could be added, a la
x86_64/evmcs.h, but it doesn't appear that Hyper-V will end up needing
a wholesale replacement for the VMCB.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../testing/selftests/kvm/include/x86_64/svm.h | 17 +++++++++++++++++
 .../selftests/kvm/x86_64/hyperv_svm_test.c     | 18 ------------------
 2 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h b/tools/testing/selftests/kvm/include/x86_64/svm.h
index c8343ff84f7f..10b9d0d4e0ec 100644
--- a/tools/testing/selftests/kvm/include/x86_64/svm.h
+++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
@@ -58,6 +58,23 @@ enum {
 	INTERCEPT_RDPRU,
 };
 
+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 (1U << 31)
 
 struct __attribute__ ((__packed__)) vmcb_control_area {
 	u32 intercept_cr;
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index a380ad7bb9b3..b366b197759f 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
@@ -23,24 +23,6 @@
 
 #define L2_GUEST_STACK_SIZE 256
 
-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 (1U << 31)
-
 void l2_guest_code(void)
 {
 	GUEST_SYNC(3);
-- 
2.37.3.968.ga6b4b080e4-goog

[PATCH 3/4] KVM: SVM: Add a proper field for Hyper-V VMCB enlightenments

[Sean Christopherson]

Add a union to provide hv_enlightenments side-by-side with the sw_reserved
bytes that Hyper-V's enlightenments overlay.  Casting sw_reserved
everywhere is messy, confusing, and unnecessarily unsafe.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/svm.h                        |  7 ++++++-
 arch/x86/kvm/svm/nested.c                         |  9 ++++-----
 arch/x86/kvm/svm/svm.h                            |  5 ++++-
 arch/x86/kvm/svm/svm_onhyperv.c                   |  2 +-
 arch/x86/kvm/svm/svm_onhyperv.h                   | 15 +++++++--------
 tools/testing/selftests/kvm/include/x86_64/svm.h  |  5 ++++-
 .../selftests/kvm/x86_64/hyperv_svm_test.c        |  3 +--
 7 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 0361626841bc..6befed2b30a6 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -5,6 +5,8 @@
 #include <uapi/asm/svm.h>
 #include <uapi/asm/kvm.h>
 
+#include <asm/hyperv-tlfs.h>
+
 /*
  * 32-bit intercept words in the VMCB Control Area, starting
  * at Byte offset 000h.
@@ -161,7 +163,10 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 	 * Offset 0x3e0, 32 bytes reserved
 	 * for use by hypervisor/software.
 	 */
-	u8 reserved_sw[32];
+	union {
+		struct hv_enlightenments hv_enlightenments;
+		u8 reserved_sw[32];
+	};
 };
 
 
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 76dcc8a3e849..a6a87d9743ce 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -201,8 +201,7 @@ void recalc_intercepts(struct vcpu_svm *svm)
  */
 static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 {
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)svm->nested.ctl.reserved_sw;
+	struct hv_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
 	int i;
 
 	/*
@@ -391,8 +390,8 @@ void __nested_copy_vmcb_control_to_cache(struct kvm_vcpu *vcpu,
 	/* Hyper-V extensions (Enlightened VMCB) */
 	if (kvm_hv_hypercall_enabled(vcpu)) {
 		to->clean = from->clean;
-		memcpy(to->reserved_sw, from->reserved_sw,
-		       sizeof(struct hv_enlightenments));
+		memcpy(&to->hv_enlightenments, &from->hv_enlightenments,
+		       sizeof(to->hv_enlightenments));
 	}
 }
 
@@ -1485,7 +1484,7 @@ static void nested_copy_vmcb_cache_to_control(struct vmcb_control_area *dst,
 	dst->virt_ext              = from->virt_ext;
 	dst->pause_filter_count   = from->pause_filter_count;
 	dst->pause_filter_thresh  = from->pause_filter_thresh;
-	/* 'clean' and 'reserved_sw' are not changed by KVM */
+	/* 'clean' and 'hv_enlightenments' are not changed by KVM */
 }
 
 static int svm_get_nested_state(struct kvm_vcpu *vcpu,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 6a7686bf6900..9eb2fc76732f 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -151,7 +151,10 @@ struct vmcb_ctrl_area_cached {
 	u64 nested_cr3;
 	u64 virt_ext;
 	u32 clean;
-	u8 reserved_sw[32];
+	union {
+		struct hv_enlightenments hv_enlightenments;
+		u8 reserved_sw[32];
+	};
 };
 
 struct svm_nested_state {
diff --git a/arch/x86/kvm/svm/svm_onhyperv.c b/arch/x86/kvm/svm/svm_onhyperv.c
index 8cdc62c74a96..5d4036611a37 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.c
+++ b/arch/x86/kvm/svm/svm_onhyperv.c
@@ -26,7 +26,7 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu)
 	if (!*p_hv_pa_pg)
 		return -ENOMEM;
 
-	hve = (struct hv_enlightenments *)to_svm(vcpu)->vmcb->control.reserved_sw;
+	hve = &to_svm(vcpu)->vmcb->control.hv_enlightenments;
 
 	hve->partition_assist_page = __pa(*p_hv_pa_pg);
 	hve->hv_vm_id = (unsigned long)vcpu->kvm;
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index 8d02654ad6f8..c8f8045305be 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -18,8 +18,10 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu);
 
 static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
 {
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
+
+	BUILD_BUG_ON(sizeof(vmcb->control.hv_enlightenments) !=
+		     sizeof(vmcb->control.reserved_sw));
 
 	if (npt_enabled &&
 	    ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB)
@@ -61,18 +63,15 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
 		struct kvm_vcpu *vcpu)
 {
 	struct vmcb *vmcb = to_svm(vcpu)->vmcb;
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
 
 	if (hve->hv_enlightenments_control.msr_bitmap)
 		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
 }
 
-static inline void svm_hv_update_vp_id(struct vmcb *vmcb,
-		struct kvm_vcpu *vcpu)
+static inline void svm_hv_update_vp_id(struct vmcb *vmcb, struct kvm_vcpu *vcpu)
 {
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
 	u32 vp_index = kvm_hv_get_vpindex(vcpu);
 
 	if (hve->hv_vp_id != vp_index) {
diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h b/tools/testing/selftests/kvm/include/x86_64/svm.h
index 10b9d0d4e0ec..0c32549c6b64 100644
--- a/tools/testing/selftests/kvm/include/x86_64/svm.h
+++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
@@ -123,7 +123,10 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 	 * Offset 0x3e0, 32 bytes reserved
 	 * for use by hypervisor/software.
 	 */
-	u8 reserved_sw[32];
+	union {
+		struct hv_enlightenments hv_enlightenments;
+		u8 reserved_sw[32];
+	};
 };
 
 
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index b366b197759f..81b204ee509a 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
@@ -46,8 +46,7 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
 {
 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
 	struct vmcb *vmcb = svm->vmcb;
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
 
 	GUEST_SYNC(1);
 
-- 
2.37.3.968.ga6b4b080e4-goog

[PATCH 4/4] x86/hyperv: KVM: Rename "hv_enlightenments" to "hv_vmcb_enlightenments"

[Sean Christopherson]

Now that KVM isn't littered with "struct hv_enlightenments" casts, rename
the struct to "hv_vmcb_enlightenments" to highlight the fact that the
struct is specifically for SVM's VMCB.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/hyperv-tlfs.h                   | 2 +-
 arch/x86/include/asm/svm.h                           | 2 +-
 arch/x86/kvm/svm/nested.c                            | 2 +-
 arch/x86/kvm/svm/svm.h                               | 2 +-
 arch/x86/kvm/svm/svm_onhyperv.c                      | 2 +-
 arch/x86/kvm/svm/svm_onhyperv.h                      | 6 +++---
 tools/testing/selftests/kvm/include/x86_64/svm.h     | 4 ++--
 tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c | 2 +-
 8 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 4c4f81daf5a2..f7a431bcb2c3 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -588,7 +588,7 @@ struct hv_enlightened_vmcs {
  * Hyper-V uses the software reserved 32 bytes in VMCB control area to expose
  * SVM enlightenments to guests.
  */
-struct hv_enlightenments {
+struct hv_vmcb_enlightenments {
 	struct __packed hv_enlightenments_control {
 		u32 nested_flush_hypercall:1;
 		u32 msr_bitmap:1;
diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 6befed2b30a6..621f064bb7cc 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -164,7 +164,7 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 	 * for use by hypervisor/software.
 	 */
 	union {
-		struct hv_enlightenments hv_enlightenments;
+		struct hv_vmcb_enlightenments hv_enlightenments;
 		u8 reserved_sw[32];
 	};
 };
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index a6a87d9743ce..bc9fb4dbf0ae 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -201,7 +201,7 @@ void recalc_intercepts(struct vcpu_svm *svm)
  */
 static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 {
-	struct hv_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
+	struct hv_vmcb_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
 	int i;
 
 	/*
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 9eb2fc76732f..5e1178bc9a64 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -152,7 +152,7 @@ struct vmcb_ctrl_area_cached {
 	u64 virt_ext;
 	u32 clean;
 	union {
-		struct hv_enlightenments hv_enlightenments;
+		struct hv_vmcb_enlightenments hv_enlightenments;
 		u8 reserved_sw[32];
 	};
 };
diff --git a/arch/x86/kvm/svm/svm_onhyperv.c b/arch/x86/kvm/svm/svm_onhyperv.c
index 5d4036611a37..0b657c7cd21b 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.c
+++ b/arch/x86/kvm/svm/svm_onhyperv.c
@@ -16,7 +16,7 @@
 
 int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu)
 {
-	struct hv_enlightenments *hve;
+	struct hv_vmcb_enlightenments *hve;
 	struct hv_partition_assist_pg **p_hv_pa_pg =
 			&to_kvm_hv(vcpu->kvm)->hv_pa_pg;
 
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index c8f8045305be..e08cd7192559 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -18,7 +18,7 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu);
 
 static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
 {
-	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
+	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
 
 	BUILD_BUG_ON(sizeof(vmcb->control.hv_enlightenments) !=
 		     sizeof(vmcb->control.reserved_sw));
@@ -63,7 +63,7 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
 		struct kvm_vcpu *vcpu)
 {
 	struct vmcb *vmcb = to_svm(vcpu)->vmcb;
-	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
+	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
 
 	if (hve->hv_enlightenments_control.msr_bitmap)
 		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
@@ -71,7 +71,7 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
 
 static inline void svm_hv_update_vp_id(struct vmcb *vmcb, struct kvm_vcpu *vcpu)
 {
-	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
+	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
 	u32 vp_index = kvm_hv_get_vpindex(vcpu);
 
 	if (hve->hv_vp_id != vp_index) {
diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h b/tools/testing/selftests/kvm/include/x86_64/svm.h
index 0c32549c6b64..49292190c219 100644
--- a/tools/testing/selftests/kvm/include/x86_64/svm.h
+++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
@@ -58,7 +58,7 @@ enum {
 	INTERCEPT_RDPRU,
 };
 
-struct hv_enlightenments {
+struct hv_vmcb_enlightenments {
 	struct __packed hv_enlightenments_control {
 		u32 nested_flush_hypercall:1;
 		u32 msr_bitmap:1;
@@ -124,7 +124,7 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 	 * for use by hypervisor/software.
 	 */
 	union {
-		struct hv_enlightenments hv_enlightenments;
+		struct hv_vmcb_enlightenments hv_enlightenments;
 		u8 reserved_sw[32];
 	};
 };
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index 81b204ee509a..f8e43c798c86 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
@@ -46,7 +46,7 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
 {
 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
 	struct vmcb *vmcb = svm->vmcb;
-	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
+	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
 
 	GUEST_SYNC(1);
 
-- 
2.37.3.968.ga6b4b080e4-goog

RE: [PATCH 4/4] x86/hyperv: KVM: Rename "hv_enlightenments" to "hv_vmcb_enlightenments"

[Michael Kelley (LINUX)]

From: Sean Christopherson <seanjc@google.com> Sent: Wednesday, September 21, 2022 1:16 PM
> 
> Now that KVM isn't littered with "struct hv_enlightenments" casts, rename
> the struct to "hv_vmcb_enlightenments" to highlight the fact that the
> struct is specifically for SVM's VMCB.
> 
> No functional change intended.
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  arch/x86/include/asm/hyperv-tlfs.h                   | 2 +-
>  arch/x86/include/asm/svm.h                           | 2 +-
>  arch/x86/kvm/svm/nested.c                            | 2 +-
>  arch/x86/kvm/svm/svm.h                               | 2 +-
>  arch/x86/kvm/svm/svm_onhyperv.c                      | 2 +-
>  arch/x86/kvm/svm/svm_onhyperv.h                      | 6 +++---
>  tools/testing/selftests/kvm/include/x86_64/svm.h     | 4 ++--
>  tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c | 2 +-
>  8 files changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index 4c4f81daf5a2..f7a431bcb2c3 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -588,7 +588,7 @@ struct hv_enlightened_vmcs {
>   * Hyper-V uses the software reserved 32 bytes in VMCB control area to expose
>   * SVM enlightenments to guests.
>   */
> -struct hv_enlightenments {
> +struct hv_vmcb_enlightenments {
>  	struct __packed hv_enlightenments_control {
>  		u32 nested_flush_hypercall:1;
>  		u32 msr_bitmap:1;
> diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
> index 6befed2b30a6..621f064bb7cc 100644
> --- a/arch/x86/include/asm/svm.h
> +++ b/arch/x86/include/asm/svm.h
> @@ -164,7 +164,7 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
>  	 * for use by hypervisor/software.
>  	 */
>  	union {
> -		struct hv_enlightenments hv_enlightenments;
> +		struct hv_vmcb_enlightenments hv_enlightenments;
>  		u8 reserved_sw[32];
>  	};
>  };
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index a6a87d9743ce..bc9fb4dbf0ae 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -201,7 +201,7 @@ void recalc_intercepts(struct vcpu_svm *svm)
>   */
>  static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
>  {
> -	struct hv_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
> +	struct hv_vmcb_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
>  	int i;
> 
>  	/*
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index 9eb2fc76732f..5e1178bc9a64 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -152,7 +152,7 @@ struct vmcb_ctrl_area_cached {
>  	u64 virt_ext;
>  	u32 clean;
>  	union {
> -		struct hv_enlightenments hv_enlightenments;
> +		struct hv_vmcb_enlightenments hv_enlightenments;
>  		u8 reserved_sw[32];
>  	};
>  };
> diff --git a/arch/x86/kvm/svm/svm_onhyperv.c b/arch/x86/kvm/svm/svm_onhyperv.c
> index 5d4036611a37..0b657c7cd21b 100644
> --- a/arch/x86/kvm/svm/svm_onhyperv.c
> +++ b/arch/x86/kvm/svm/svm_onhyperv.c
> @@ -16,7 +16,7 @@
> 
>  int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu)
>  {
> -	struct hv_enlightenments *hve;
> +	struct hv_vmcb_enlightenments *hve;
>  	struct hv_partition_assist_pg **p_hv_pa_pg =
>  			&to_kvm_hv(vcpu->kvm)->hv_pa_pg;
> 
> diff --git a/arch/x86/kvm/svm/svm_onhyperv.h
> b/arch/x86/kvm/svm/svm_onhyperv.h
> index c8f8045305be..e08cd7192559 100644
> --- a/arch/x86/kvm/svm/svm_onhyperv.h
> +++ b/arch/x86/kvm/svm/svm_onhyperv.h
> @@ -18,7 +18,7 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu);
> 
>  static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
>  {
> -	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
> +	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
> 
>  	BUILD_BUG_ON(sizeof(vmcb->control.hv_enlightenments) !=
>  		     sizeof(vmcb->control.reserved_sw));
> @@ -63,7 +63,7 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
>  		struct kvm_vcpu *vcpu)
>  {
>  	struct vmcb *vmcb = to_svm(vcpu)->vmcb;
> -	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
> +	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
> 
>  	if (hve->hv_enlightenments_control.msr_bitmap)
>  		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
> @@ -71,7 +71,7 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
> 
>  static inline void svm_hv_update_vp_id(struct vmcb *vmcb, struct kvm_vcpu *vcpu)
>  {
> -	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
> +	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
>  	u32 vp_index = kvm_hv_get_vpindex(vcpu);
> 
>  	if (hve->hv_vp_id != vp_index) {
> diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h
> b/tools/testing/selftests/kvm/include/x86_64/svm.h
> index 0c32549c6b64..49292190c219 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/svm.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
> @@ -58,7 +58,7 @@ enum {
>  	INTERCEPT_RDPRU,
>  };
> 
> -struct hv_enlightenments {
> +struct hv_vmcb_enlightenments {
>  	struct __packed hv_enlightenments_control {
>  		u32 nested_flush_hypercall:1;
>  		u32 msr_bitmap:1;
> @@ -124,7 +124,7 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
>  	 * for use by hypervisor/software.
>  	 */
>  	union {
> -		struct hv_enlightenments hv_enlightenments;
> +		struct hv_vmcb_enlightenments hv_enlightenments;
>  		u8 reserved_sw[32];
>  	};
>  };
> diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
> b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
> index 81b204ee509a..f8e43c798c86 100644
> --- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
> @@ -46,7 +46,7 @@ static void __attribute__((__flatten__)) guest_code(struct
> svm_test_data *svm)
>  {
>  	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
>  	struct vmcb *vmcb = svm->vmcb;
> -	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
> +	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
> 
>  	GUEST_SYNC(1);
> 
> --
> 2.37.3.968.ga6b4b080e4-goog

Reviewed-by: Michael Kelley <mikelley@microsoft.com>