[RFC PATCH v2 05/25] KVM: SVM: Add helpers to set/clear ASID flush in VMCB

[Yosry Ahmed]

Introduce set/clear helpers to set tlb_ctl to
TLB_CONTROL_FLUSH_ASID or TLB_CONTROL_DO_NOTHING. Incoming changes will
eliminate the use of TLB_CONTROL_FLUSH_ALL_ASID except as a fallback
when FLUSHBYASID is not available, so the helpers will create a common
path for this.

Signed-off-by: Yosry Ahmed <yosry@xxxxxxxxxx>
---
 arch/x86/kvm/svm/nested.c |  2 +-
 arch/x86/kvm/svm/sev.c    |  2 +-
 arch/x86/kvm/svm/svm.c    |  4 ++--
 arch/x86/kvm/svm/svm.h    | 10 ++++++++++
 4 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index c85aa5cf670f4..f891299d278a0 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -928,7 +928,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm)
 	/* Done at vmrun: asid.  */
 
 	/* Also overwritten later if necessary.  */
-	vmcb02->control.tlb_ctl = TLB_CONTROL_DO_NOTHING;
+	vmcb_clr_flush_asid(vmcb02);
 
 	/* Use vmcb01 MMU and format if guest does not use nNPT */
 	if (nested_npt_enabled(svm)) {
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 74fb15551e83f..026b070522dac 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3569,7 +3569,7 @@ int pre_sev_run(struct vcpu_svm *svm, int cpu)
 		return 0;
 
 	sd->sev_vmcbs[asid] = svm->vmcb;
-	svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
+	vmcb_set_flush_asid(svm->vmcb);
 	vmcb_mark_dirty(svm->vmcb, VMCB_ASID);
 	return 0;
 }
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 526e0fdcd16be..a7cc3cb101e57 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4186,7 +4186,7 @@ static void svm_flush_tlb_asid(struct kvm_vcpu *vcpu)
 	 * VM-Exit (via kvm_mmu_reset_context()).
 	 */
 	if (static_cpu_has(X86_FEATURE_FLUSHBYASID))
-		svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
+		vmcb_set_flush_asid(svm->vmcb);
 	else
 		svm->current_vmcb->asid_generation--;
 }
@@ -4599,7 +4599,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu, u64 run_flags)
 		vcpu->arch.nested_run_pending = 0;
 	}
 
-	svm->vmcb->control.tlb_ctl = TLB_CONTROL_DO_NOTHING;
+	vmcb_clr_flush_asid(svm->vmcb);
 
 	/*
 	 * Unconditionally mask off the CLEAR_RAP bit, the AND is just as cheap
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 716be21fba335..5b4613b4d7bc2 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -476,6 +476,16 @@ static inline void vmcb_set_gpat(struct vmcb *vmcb, u64 data)
 	vmcb_mark_dirty(vmcb, VMCB_NPT);
 }
 
+static inline void vmcb_set_flush_asid(struct vmcb *vmcb)
+{
+	vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
+}
+
+static inline void vmcb_clr_flush_asid(struct vmcb *vmcb)
+{
+	vmcb->control.tlb_ctl = TLB_CONTROL_DO_NOTHING;
+}
+
 static __always_inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
 {
 	return container_of(vcpu, struct vcpu_svm, vcpu);
-- 
2.54.0.1136.gdb2ca164c4-goog