[PATCH v5 02/26] KVM: SVM: Switch svm_copy_lbrs() to a macro

[Yosry Ahmed <yosry.ahmed@linux.dev>]

In preparation for using svm_copy_lbrs() with 'struct vmcb_save_area'
without a containing 'struct vmcb', and later even 'struct
vmcb_save_area_cached', make it a macro.

Macros are generally not preferred compared to functions, mainly due to
type-safety. However, in this case it seems like having a simple macro
copying a few fields is better than copy-pasting the same 5 lines of
code in different places.

Cc: stable@vger.kernel.org
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
---
 arch/x86/kvm/svm/nested.c |  8 ++++----
 arch/x86/kvm/svm/svm.c    |  9 ---------
 arch/x86/kvm/svm/svm.h    | 10 +++++++++-
 3 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index a31f3be1e16e..f7d5db0af69a 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -709,10 +709,10 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12
 		 * Reserved bits of DEBUGCTL are ignored.  Be consistent with
 		 * svm_set_msr's definition of reserved bits.
 		 */
-		svm_copy_lbrs(vmcb02, vmcb12);
+		svm_copy_lbrs(&vmcb02->save, &vmcb12->save);
 		vmcb02->save.dbgctl &= ~DEBUGCTL_RESERVED_BITS;
 	} else {
-		svm_copy_lbrs(vmcb02, vmcb01);
+		svm_copy_lbrs(&vmcb02->save, &vmcb01->save);
 	}
 	vmcb_mark_dirty(vmcb02, VMCB_LBR);
 	svm_update_lbrv(&svm->vcpu);
@@ -1234,9 +1234,9 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 
 	if (unlikely(guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) &&
 		     (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) {
-		svm_copy_lbrs(vmcb12, vmcb02);
+		svm_copy_lbrs(&vmcb12->save, &vmcb02->save);
 	} else {
-		svm_copy_lbrs(vmcb01, vmcb02);
+		svm_copy_lbrs(&vmcb01->save, &vmcb02->save);
 		vmcb_mark_dirty(vmcb01, VMCB_LBR);
 	}
 
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 98cbd7c7beed..798f2c84d80b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -841,15 +841,6 @@ static void svm_recalc_msr_intercepts(struct kvm_vcpu *vcpu)
 	 */
 }
 
-void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb)
-{
-	to_vmcb->save.dbgctl		= from_vmcb->save.dbgctl;
-	to_vmcb->save.br_from		= from_vmcb->save.br_from;
-	to_vmcb->save.br_to		= from_vmcb->save.br_to;
-	to_vmcb->save.last_excp_from	= from_vmcb->save.last_excp_from;
-	to_vmcb->save.last_excp_to	= from_vmcb->save.last_excp_to;
-}
-
 static void __svm_enable_lbrv(struct kvm_vcpu *vcpu)
 {
 	to_svm(vcpu)->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index ebd7b36b1ceb..44d767cd1d25 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -713,8 +713,16 @@ static inline void *svm_vcpu_alloc_msrpm(void)
 	return svm_alloc_permissions_map(MSRPM_SIZE, GFP_KERNEL_ACCOUNT);
 }
 
+#define svm_copy_lbrs(to, from)					\
+do {								\
+	(to)->dbgctl		= (from)->dbgctl;		\
+	(to)->br_from		= (from)->br_from;		\
+	(to)->br_to		= (from)->br_to;		\
+	(to)->last_excp_from	= (from)->last_excp_from;	\
+	(to)->last_excp_to	= (from)->last_excp_to;		\
+} while (0)
+
 void svm_vcpu_free_msrpm(void *msrpm);
-void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb);
 void svm_enable_lbrv(struct kvm_vcpu *vcpu);
 void svm_update_lbrv(struct kvm_vcpu *vcpu);
 
-- 
2.53.0.rc2.204.g2597b5adb4-goog