KVM: arm/arm64: add irqfd support
This patch enables irqfd on arm/arm64.
Both irqfd and resamplefd are supported. Injection is implemented
in vgic.c without routing.
This patch enables CONFIG_HAVE_KVM_EVENTFD and CONFIG_HAVE_KVM_IRQFD.
KVM_CAP_IRQFD is now advertised. KVM_CAP_IRQFD_RESAMPLE capability
automatically is advertised as soon as CONFIG_HAVE_KVM_IRQFD is set.
Irqfd injection is restricted to SPI. The rationale behind not
supporting PPI irqfd injection is that any device using a PPI would
be a private-to-the-CPU device (timer for instance), so its state
would have to be context-switched along with the VCPU and would
require in-kernel wiring anyhow. It is not a relevant use case for
irqfds.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index 0db25bc..2499867 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -198,6 +198,9 @@
/* Highest supported SPI, from VGIC_NR_IRQS */
#define KVM_ARM_IRQ_GIC_MAX 127
+/* One single KVM irqchip, ie. the VGIC */
+#define KVM_NR_IRQCHIPS 1
+
/* PSCI interface */
#define KVM_PSCI_FN_BASE 0x95c1ba5e
#define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n))
diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
index 83a448e..f1f79d1 100644
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -28,6 +28,8 @@
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
select SRCU
select MMU_NOTIFIER
+ select HAVE_KVM_EVENTFD
+ select HAVE_KVM_IRQFD
depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER
---help---
Support hosting virtualized guest machines.
diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
index 60be7be..a093bf1 100644
--- a/arch/arm/kvm/Makefile
+++ b/arch/arm/kvm/Makefile
@@ -15,7 +15,7 @@
AFLAGS_interrupts.o := -Wa,-march=armv7-a$(plus_virt)
KVM := ../../../virt/kvm
-kvm-arm-y = $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o
+kvm-arm-y = $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o
obj-y += kvm-arm.o init.o interrupts.o
obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 5e893eb..cc96619 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -171,6 +171,7 @@
int r;
switch (ext) {
case KVM_CAP_IRQCHIP:
+ case KVM_CAP_IRQFD:
case KVM_CAP_DEVICE_CTRL:
case KVM_CAP_USER_MEMORY:
case KVM_CAP_SYNC_MMU:
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 3ef77a4..c154c0b7 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -191,6 +191,9 @@
/* Highest supported SPI, from VGIC_NR_IRQS */
#define KVM_ARM_IRQ_GIC_MAX 127
+/* One single KVM irqchip, ie. the VGIC */
+#define KVM_NR_IRQCHIPS 1
+
/* PSCI interface */
#define KVM_PSCI_FN_BASE 0x95c1ba5e
#define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n))
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 05f56ce..5105e29 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -28,6 +28,8 @@
select KVM_ARM_HOST
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
select SRCU
+ select HAVE_KVM_EVENTFD
+ select HAVE_KVM_IRQFD
---help---
Support hosting virtualized guest machines.
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index c92b26a..b22c636 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -11,7 +11,7 @@
obj-$(CONFIG_KVM_ARM_HOST) += kvm.o
-kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o
+kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/arm.o $(ARM)/mmu.o $(ARM)/mmio.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/psci.o $(ARM)/perf.o