linux-kernel - [PATCH v2 4/9] KVM: mips, x86: do not rely on KVM_REQ

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Date:   Thu, 11 Aug 2022 17:06:00 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     seanjc@...gle.com, mlevitsk@...hat.com, vkuznets@...hat.com
Subject: [PATCH v2 4/9] KVM: mips, x86: do not rely on KVM_REQ_UNHALT

KVM_REQ_UNHALT is now available as the return value from kvm_vcpu_halt
or kvm_vcpu_block, so the request can be simply cleared just like all
other architectures do.

No functional change intended.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/mips/kvm/emulate.c | 8 ++++----
 arch/x86/kvm/x86.c      | 8 +++++---
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index b494d8d39290..77d760d45c48 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -944,6 +944,7 @@ enum hrtimer_restart kvm_mips_count_timeout(struct kvm_vcpu *vcpu)
 
 enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
 {
+	int r;
 	kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
 		  vcpu->arch.pending_exceptions);
 
@@ -952,16 +953,15 @@ enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
 	if (!vcpu->arch.pending_exceptions) {
 		kvm_vz_lose_htimer(vcpu);
 		vcpu->arch.wait = 1;
-		kvm_vcpu_halt(vcpu);
+		r = kvm_vcpu_halt(vcpu);
 
 		/*
 		 * We we are runnable, then definitely go off to user space to
 		 * check if any I/O interrupts are pending.
 		 */
-		if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
-			kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+		kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+		if (r > 0)
 			vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
-		}
 	}
 
 	return EMULATE_DONE;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c44348bb6ef2..416df0fc7fda 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10611,6 +10611,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 static inline int vcpu_block(struct kvm_vcpu *vcpu)
 {
 	bool hv_timer;
+	int r;
 
 	if (!kvm_arch_vcpu_runnable(vcpu)) {
 		/*
@@ -10626,15 +10627,16 @@ static inline int vcpu_block(struct kvm_vcpu *vcpu)
 
 		kvm_vcpu_srcu_read_unlock(vcpu);
 		if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
-			kvm_vcpu_halt(vcpu);
+			r = kvm_vcpu_halt(vcpu);
 		else
-			kvm_vcpu_block(vcpu);
+			r = kvm_vcpu_block(vcpu);
 		kvm_vcpu_srcu_read_lock(vcpu);
 
 		if (hv_timer)
 			kvm_lapic_switch_to_hv_timer(vcpu);
 
-		if (!kvm_check_request(KVM_REQ_UNHALT, vcpu))
+		kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+		if (r <= 0)
 			return 1;
 	}
 
-- 
2.31.1