[PATCH 34/37] KVM: arm64: nVHE: Unify timer restore paths

From: Andrew Scull <ascull@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: maz@kernel.org, kernel-team@android.com
Subject: [PATCH 34/37] KVM: arm64: nVHE: Unify timer restore paths
Date: Wed, 15 Jul 2020 19:44:35 +0100	[thread overview]
Message-ID: <20200715184438.1390996-35-ascull@google.com> (raw)
In-Reply-To: <20200715184438.1390996-1-ascull@google.com>

Different actions are taken depending on whether the vcpu is the host or
not but this choice could easily be changed to another property of the
vcpu, if required.

Signed-off-by: Andrew Scull <ascull@google.com>
---
 arch/arm64/include/asm/kvm_hyp.h   |  3 +--
 arch/arm64/kvm/hyp/nvhe/switch.c   |  7 ++----
 arch/arm64/kvm/hyp/nvhe/timer-sr.c | 35 +++++++++++-------------------
 3 files changed, 16 insertions(+), 29 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index d4d366e0d78d..fdacb26ac475 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -81,8 +81,7 @@ void __vgic_v3_restore_aprs(struct vgic_v3_cpu_if *cpu_if);
 int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
 
 #ifdef __KVM_NVHE_HYPERVISOR__
-void __timer_enable_traps(struct kvm_vcpu *vcpu);
-void __timer_disable_traps(struct kvm_vcpu *vcpu);
+void __timer_restore_traps(struct kvm_vcpu *vcpu);
 #endif
 
 #ifdef __KVM_NVHE_HYPERVISOR__
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index fa90fc776374..05f1cf7ee9e7 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -131,15 +131,11 @@ static void __kvm_vcpu_switch_to_guest(struct kvm_vcpu *host_vcpu,
 	}
 
 	__pmu_switch_to_guest();
-
-	__timer_enable_traps(vcpu);
 }
 
 static void __kvm_vcpu_switch_to_host(struct kvm_vcpu *host_vcpu,
 				      struct kvm_vcpu *vcpu)
 {
-	__timer_disable_traps(vcpu);
-
 	__pmu_switch_to_host();
 
 	/* Returning to host will clear PSR.I, remask PMR if needed */
@@ -211,6 +207,7 @@ static void __vcpu_restore_state(struct kvm_vcpu *vcpu, bool restore_debug)
 		__activate_traps(vcpu);
 
 	__hyp_vgic_restore_state(vcpu);
+	__timer_restore_traps(vcpu);
 
 	/*
 	 * This must come after restoring the sysregs since SPE may make use if
@@ -280,7 +277,7 @@ void __noreturn hyp_panic(void)
 	unsigned long str_va;
 
 	if (vcpu != host_vcpu) {
-		__timer_disable_traps(vcpu);
+		__timer_restore_traps(host_vcpu);
 		__deactivate_traps(host_vcpu, vcpu);
 		__restore_stage2(host_vcpu);
 		__sysreg_restore_state_nvhe(&host_vcpu->arch.ctxt);
diff --git a/arch/arm64/kvm/hyp/nvhe/timer-sr.c b/arch/arm64/kvm/hyp/nvhe/timer-sr.c
index 9072e71693ba..914d2624467d 100644
--- a/arch/arm64/kvm/hyp/nvhe/timer-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/timer-sr.c
@@ -19,30 +19,21 @@ void __kvm_timer_set_cntvoff(u64 cntvoff)
  * Should only be called on non-VHE systems.
  * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
  */
-void __timer_disable_traps(struct kvm_vcpu *vcpu)
+void __timer_restore_traps(struct kvm_vcpu *vcpu)
 {
-	u64 val;
+	u64 val = read_sysreg(cnthctl_el2);
 
-	/* Allow physical timer/counter access for the host */
-	val = read_sysreg(cnthctl_el2);
-	val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
-	write_sysreg(val, cnthctl_el2);
-}
-
-/*
- * Should only be called on non-VHE systems.
- * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
- */
-void __timer_enable_traps(struct kvm_vcpu *vcpu)
-{
-	u64 val;
+	if (vcpu->arch.ctxt.is_host) {
+		/* Allow physical timer/counter access for the host */
+		val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
+	} else {
+		/*
+		 * Disallow physical timer access for the guest
+		 * Physical counter access is allowed
+		 */
+		val &= ~CNTHCTL_EL1PCEN;
+		val |= CNTHCTL_EL1PCTEN;
+	}
 
-	/*
-	 * Disallow physical timer access for the guest
-	 * Physical counter access is allowed
-	 */
-	val = read_sysreg(cnthctl_el2);
-	val &= ~CNTHCTL_EL1PCEN;
-	val |= CNTHCTL_EL1PCTEN;
 	write_sysreg(val, cnthctl_el2);
 }
-- 
2.27.0.389.gc38d7665816-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
