[PATCH 2/3] KVM: SVM: Dirty ERAPS register on all ASID TLB flushes

[Jim Mattson <jmattson@google.com>]

Per the AMD APM, ERAPS clears the Return Address Predictor (RAP/RSB) on all
implicit TLB invalidations (e.g. modifying certain CR[04] bits).

Move kvm_register_mark_dirty(vcpu, VCPU_REG_ERAPS) into
svm_flush_tlb_asid() so that any ASID-level TLB flush marks ERAPS dirty.
Centralizing the ERAPS dirty call in svm_flush_tlb_asid() ensures that all
ASID flushes (flush_tlb_current, flush_tlb_all, flush_tlb_guest) properly
set ERAP_CONTROL_CLEAR_RAP on the next VMRUN.

Remove the now redundant svm_flush_tlb_guest() wrapper.

Fixes: db5e82496492 ("KVM: SVM: Virtualize and advertise support for ERAPS")
Assisted-by: Gemini:Gemini-Next
Signed-off-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/svm/svm.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b76c6a76ce37..2514c6516fa1 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4168,6 +4168,8 @@ static void svm_flush_tlb_asid(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
+	kvm_register_mark_dirty(vcpu, VCPU_REG_ERAPS);
+
 	/*
 	 * Unlike VMX, SVM doesn't provide a way to flush only NPT TLB entries.
 	 * A TLB flush for the current ASID flushes both "host" and "guest" TLB
@@ -4226,13 +4228,6 @@ static void svm_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t gva)
 	invlpga(gva, svm->vmcb->control.asid);
 }
 
-static void svm_flush_tlb_guest(struct kvm_vcpu *vcpu)
-{
-	kvm_register_mark_dirty(vcpu, VCPU_REG_ERAPS);
-
-	svm_flush_tlb_asid(vcpu);
-}
-
 static inline void sync_cr8_to_lapic(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -5380,7 +5375,7 @@ struct kvm_x86_ops svm_x86_ops __initdata = {
 	.flush_tlb_all = svm_flush_tlb_all,
 	.flush_tlb_current = svm_flush_tlb_current,
 	.flush_tlb_gva = svm_flush_tlb_gva,
-	.flush_tlb_guest = svm_flush_tlb_guest,
+	.flush_tlb_guest = svm_flush_tlb_asid,
 
 	.vcpu_pre_run = svm_vcpu_pre_run,
 	.vcpu_run = svm_vcpu_run,
-- 
2.55.0.229.g6434b31f56-goog