[PATCH 3/7] KVM: PPC: Explicitly force IPIs when directly kicking vCPUs

[Sean Christopherson]

Explicitly force an IPI when invoking kvm_vcpu_kick() directly instead of
relying on kvm_arch_vcpu_should_kick() to unconditionally return 1/true.
This will allow dropping kvm_arch_vcpu_should_kick() in favor of
kvm_request_needs_ipi().

No functional change intended (1 || 1 == true).

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 arch/powerpc/include/asm/kvm_ppc.h | 13 ++++++++++++-
 arch/powerpc/kvm/book3s.c          |  4 ++--
 arch/powerpc/kvm/book3s_pr.c       |  2 +-
 arch/powerpc/kvm/booke.c           |  6 +++---
 arch/powerpc/kvm/e500_emulate.c    |  2 +-
 arch/powerpc/kvm/powerpc.c         |  2 +-
 6 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 169ea6a7fbad..bbe7378ad0ef 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -30,6 +30,17 @@
 #endif
 #include <asm/inst.h>
 
+/*
+ * TODO: For unknown reasons, KVM PPC has historically ignored vcpu->mode when
+ *       determining if kicking a vCPU needs an IPI.  Either document why that
+ *       behavior is necessary, or drop this helper and the @force param from
+ *       __kvm_vcpu_kick().
+ */
+static inline void kvmppc_vcpu_kick(struct kvm_vcpu *vcpu)
+{
+	__kvm_vcpu_kick(vcpu, false, true);
+}
+
 /*
  * KVMPPC_INST_SW_BREAKPOINT is debug Instruction
  * for supporting software breakpoint.
@@ -598,7 +609,7 @@ static inline void kvmppc_clear_host_ipi(int cpu)
 
 static inline void kvmppc_fast_vcpu_kick(struct kvm_vcpu *vcpu)
 {
-	kvm_vcpu_kick(vcpu);
+	kvmppc_vcpu_kick(vcpu);
 }
 
 static inline bool kvm_hv_mode_active(void)		{ return false; }
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 2efbe05caed7..dce53c5a3868 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -260,7 +260,7 @@ void kvmppc_core_queue_external(struct kvm_vcpu *vcpu,
 	 * external interrupts for the guest just before entering
 	 * the guest.  That is OK even if userspace did do a
 	 * KVM_INTERRUPT_SET on a pseries guest vcpu, because the
-	 * caller (kvm_vcpu_ioctl_interrupt) does a kvm_vcpu_kick()
+	 * caller (kvm_vcpu_ioctl_interrupt) does a kvmppc_vcpu_kick()
 	 * which ends up doing a smp_send_reschedule(), which will
 	 * pull the guest all the way out to the host, meaning that
 	 * we will call kvmppc_core_prepare_to_enter() before entering
@@ -827,7 +827,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 void kvmppc_decrementer_func(struct kvm_vcpu *vcpu)
 {
 	kvmppc_core_queue_dec(vcpu);
-	kvm_vcpu_kick(vcpu);
+	kvmppc_vcpu_kick(vcpu);
 }
 
 int kvmppc_core_vcpu_create(struct kvm_vcpu *vcpu)
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index ecfb88bf6464..1894968f2c25 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -2066,7 +2066,7 @@ static struct kvmppc_ops kvm_ops_pr = {
 	.emulate_op = kvmppc_core_emulate_op_pr,
 	.emulate_mtspr = kvmppc_core_emulate_mtspr_pr,
 	.emulate_mfspr = kvmppc_core_emulate_mfspr_pr,
-	.fast_vcpu_kick = kvm_vcpu_kick,
+	.fast_vcpu_kick = kvmppc_vcpu_kick,
 	.arch_vm_ioctl  = kvm_arch_vm_ioctl_pr,
 #ifdef CONFIG_PPC_BOOK3S_64
 	.hcall_implemented = kvmppc_hcall_impl_pr,
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 13ad4cf5fa71..fd7f24a68b31 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -650,7 +650,7 @@ static void kvmppc_watchdog_func(struct timer_list *t)
 	if (new_tsr & TSR_WIS) {
 		smp_wmb();
 		kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
-		kvm_vcpu_kick(vcpu);
+		kvmppc_vcpu_kick(vcpu);
 	}
 
 	/*
@@ -661,7 +661,7 @@ static void kvmppc_watchdog_func(struct timer_list *t)
 	    vcpu->arch.watchdog_enabled) {
 		smp_wmb();
 		kvm_make_request(KVM_REQ_WATCHDOG, vcpu);
-		kvm_vcpu_kick(vcpu);
+		kvmppc_vcpu_kick(vcpu);
 	}
 
 	/*
@@ -1872,7 +1872,7 @@ void kvmppc_set_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits)
 	set_bits(tsr_bits, &vcpu->arch.tsr);
 	smp_wmb();
 	kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
-	kvm_vcpu_kick(vcpu);
+	kvmppc_vcpu_kick(vcpu);
 }
 
 void kvmppc_clr_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits)
diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c
index 051102d50c31..10cd6b4ab456 100644
--- a/arch/powerpc/kvm/e500_emulate.c
+++ b/arch/powerpc/kvm/e500_emulate.c
@@ -75,7 +75,7 @@ static int kvmppc_e500_emul_msgsnd(struct kvm_vcpu *vcpu, int rb)
 		int cpir = cvcpu->arch.shared->pir;
 		if ((param & PPC_DBELL_MSG_BRDCAST) || (cpir == pir)) {
 			set_bit(prio, &cvcpu->arch.pending_exceptions);
-			kvm_vcpu_kick(cvcpu);
+			kvmppc_vcpu_kick(cvcpu);
 		}
 	}
 
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 9194cf492d1c..09c94b849185 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -1903,7 +1903,7 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
 
 	kvmppc_core_queue_external(vcpu, irq);
 
-	kvm_vcpu_kick(vcpu);
+	kvmppc_vcpu_kick(vcpu);
 
 	return 0;
 }
-- 
2.56.0.313.g2479322e68-goog