Thread (28 messages) 28 messages, 2 authors, 2020-03-24
STALE2291d REVIEWED: 1 (1M)
Revisions (5)
  1. v1 [diff vs current]
  2. v2 [diff vs current]
  3. v3 [diff vs current]
  4. v5 [diff vs current]
  5. v6 current

[PATCH v6 21/23] KVM: arm64: GICv4.1: Reload VLPI configuration on distributor enable/disable

From: Marc Zyngier <maz@kernel.org>
Date: 2020-03-20 18:51:23
Also in: kvm, kvmarm, lkml
Subsystem: arm port, arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers: Russell King, Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds

Each time a Group-enable bit gets flipped, the state of these bits
needs to be forwarded to the hardware. This is a pretty heavy
handed operation, requiring all vcpus to reload their GICv4
configuration. It is thus implemented as a new request type.

These enable bits are programmed into the HW by setting the VGrp{0,1}En
fields of GICR_VPENDBASER when the vPEs are made resident again.

Of course, we only support Group-1 for now...

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20200304203330.4967-22-maz@kernel.org (local)
---
 arch/arm/include/asm/kvm_host.h   | 1 +
 arch/arm64/include/asm/kvm_host.h | 1 +
 virt/kvm/arm/arm.c                | 8 ++++++++
 virt/kvm/arm/vgic/vgic-mmio-v3.c  | 5 ++++-
 4 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index a827b4d60d38..3da57e863df6 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -39,6 +39,7 @@
 #define KVM_REQ_IRQ_PENDING	KVM_ARCH_REQ(1)
 #define KVM_REQ_VCPU_RESET	KVM_ARCH_REQ(2)
 #define KVM_REQ_RECORD_STEAL	KVM_ARCH_REQ(3)
+#define KVM_REQ_RELOAD_GICv4	KVM_ARCH_REQ(4)
 
 DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
 
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 57fd46acd058..32c8a675e5a4 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -44,6 +44,7 @@
 #define KVM_REQ_IRQ_PENDING	KVM_ARCH_REQ(1)
 #define KVM_REQ_VCPU_RESET	KVM_ARCH_REQ(2)
 #define KVM_REQ_RECORD_STEAL	KVM_ARCH_REQ(3)
+#define KVM_REQ_RELOAD_GICv4	KVM_ARCH_REQ(4)
 
 DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
 
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index eda7b624eab8..4d864f857ac8 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -625,6 +625,14 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu)
 
 		if (kvm_check_request(KVM_REQ_RECORD_STEAL, vcpu))
 			kvm_update_stolen_time(vcpu);
+
+		if (kvm_check_request(KVM_REQ_RELOAD_GICv4, vcpu)) {
+			/* The distributor enable bits were changed */
+			preempt_disable();
+			vgic_v4_put(vcpu, false);
+			vgic_v4_load(vcpu);
+			preempt_enable();
+		}
 	}
 }
 
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 905032a03886..e72dcc454247 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -132,7 +132,10 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
 		if (is_hwsgi != dist->nassgireq)
 			vgic_v4_configure_vsgis(vcpu->kvm);
 
-		if (!was_enabled && dist->enabled)
+		if (kvm_vgic_global_state.has_gicv4_1 &&
+		    was_enabled != dist->enabled)
+			kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_RELOAD_GICv4);
+		else if (!was_enabled && dist->enabled)
 			vgic_kick_vcpus(vcpu->kvm);
 
 		mutex_unlock(&vcpu->kvm->lock);
-- 
2.20.1


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