[PATCH v2 8/8] KVM: arm/arm64: register DEOI irq bypass consumer on ARM/ARM64

From: Eric Auger
Date: Thu Jun 15 2017 - 08:55:40 EST


This patch selects IRQ_BYPASS_MANAGER and HAVE_KVM_IRQ_BYPASS
configs for ARM/ARM64.

kvm_arch_has_irq_bypass() now is implemented and returns true.
As a consequence the irq bypass consumer will be registered for
ARM/ARM64 with Direct EOI/IRQ forwarding callbacks:

- stop/start: halt/resume guest execution
- add/del_producer: set/unset forwarding/DEOI at vgic/irqchip level

The consumer currently only works with a VFIO_PLATFORM producer.
In other cases, start/stop do nothing and return without error
to avoid outputting a spurious warning.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>

---

v1 -> v2:
- check the type of the producer to avoid attachement with VFIO-PCI
dummy MSI producer
---
arch/arm/kvm/Kconfig | 3 +++
arch/arm64/kvm/Kconfig | 3 +++
virt/kvm/arm/arm.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 54 insertions(+)

diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
index 90d0176..4e2b192 100644
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -3,6 +3,7 @@
#

source "virt/kvm/Kconfig"
+source "virt/lib/Kconfig"

menuconfig VIRTUALIZATION
bool "Virtualization"
@@ -35,6 +36,8 @@ config KVM
select HAVE_KVM_IRQCHIP
select HAVE_KVM_IRQ_ROUTING
select HAVE_KVM_MSI
+ select IRQ_BYPASS_MANAGER
+ select HAVE_KVM_IRQ_BYPASS
depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER
---help---
Support hosting virtualized guest machines.
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 52cb7ad..7e0d6e6 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -3,6 +3,7 @@
#

source "virt/kvm/Kconfig"
+source "virt/lib/Kconfig"

menuconfig VIRTUALIZATION
bool "Virtualization"
@@ -35,6 +36,8 @@ config KVM
select HAVE_KVM_MSI
select HAVE_KVM_IRQCHIP
select HAVE_KVM_IRQ_ROUTING
+ select IRQ_BYPASS_MANAGER
+ select HAVE_KVM_IRQ_BYPASS
---help---
Support hosting virtualized guest machines.
We don't support KVM with 16K page tables yet, due to the multiple
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 3417e18..58871f8 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -27,6 +27,8 @@
#include <linux/mman.h>
#include <linux/sched.h>
#include <linux/kvm.h>
+#include <linux/kvm_irqfd.h>
+#include <linux/irqbypass.h>
#include <trace/events/kvm.h>
#include <kvm/arm_pmu.h>

@@ -1420,6 +1422,52 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
return NULL;
}

+bool kvm_arch_has_irq_bypass(void)
+{
+ return true;
+}
+
+int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
+ struct irq_bypass_producer *prod)
+{
+ struct kvm_kernel_irqfd *irqfd =
+ container_of(cons, struct kvm_kernel_irqfd, consumer);
+
+ if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
+ return 0;
+
+ return kvm_vgic_set_forwarding(irqfd->kvm, prod->irq,
+ irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
+}
+void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
+ struct irq_bypass_producer *prod)
+{
+ struct kvm_kernel_irqfd *irqfd =
+ container_of(cons, struct kvm_kernel_irqfd, consumer);
+
+ if (prod->type != IRQ_BYPASS_VFIO_PLATFORM)
+ return;
+
+ kvm_vgic_unset_forwarding(irqfd->kvm, prod->irq,
+ irqfd->gsi + VGIC_NR_PRIVATE_IRQS);
+}
+
+void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
+{
+ struct kvm_kernel_irqfd *irqfd =
+ container_of(cons, struct kvm_kernel_irqfd, consumer);
+
+ kvm_arm_halt_guest(irqfd->kvm);
+}
+
+void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
+{
+ struct kvm_kernel_irqfd *irqfd =
+ container_of(cons, struct kvm_kernel_irqfd, consumer);
+
+ kvm_arm_resume_guest(irqfd->kvm);
+}
+
/**
* Initialize Hyp-mode and memory mappings on all CPUs.
*/
--
2.5.5