diff mbox series

[v5,21/23] KVM: arm64: GICv4.1: Reload VLPI configuration on distributor enable/disable

Message ID 20200304203330.4967-22-maz@kernel.org (mailing list archive)
State New, archived
Headers show
Series irqchip/gic-v4: GICv4.1 architecture support | expand

Commit Message

Marc Zyngier March 4, 2020, 8:33 p.m. UTC
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.

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

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 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(-)

Comments

Zenghui Yu March 18, 2020, 3:17 a.m. UTC | #1
On 2020/3/5 4:33, Marc Zyngier wrote:
> 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.

[note to myself]
... and the status are forwarded to HW by programming VGrp{0,1}En
fields of GICR_VPENDBASER when vPEs are made resident next time.

> 
> Of course, we only support Group-1 for now...
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>


Thanks
Marc Zyngier March 19, 2020, 12:18 p.m. UTC | #2
On 2020-03-18 03:17, Zenghui Yu wrote:
> On 2020/3/5 4:33, Marc Zyngier wrote:
>> 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.
> 
> [note to myself]
> ... and the status are forwarded to HW by programming VGrp{0,1}En
> fields of GICR_VPENDBASER when vPEs are made resident next time.

I've added something based on this comment to the commit message.

Thanks!

         M.
diff mbox series

Patch

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 442f3b8c2559..48fd9fc229a2 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);