[PATCH 08/27] KVM: arm/arm64: add irqfd support
Marc Zyngier
marc.zyngier at arm.com
Thu Apr 2 03:05:12 PDT 2015
From: Eric Auger <eric.auger at linaro.org>
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 at linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
Acked-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
Documentation/virtual/kvm/api.txt | 6 ++++-
arch/arm/include/uapi/asm/kvm.h | 3 +++
arch/arm/kvm/Kconfig | 2 ++
arch/arm/kvm/Makefile | 2 +-
arch/arm/kvm/arm.c | 1 +
arch/arm64/include/uapi/asm/kvm.h | 3 +++
arch/arm64/kvm/Kconfig | 2 ++
arch/arm64/kvm/Makefile | 2 +-
virt/kvm/arm/vgic.c | 48 +++++++++++++++++++++++++++++++++++++++
9 files changed, 66 insertions(+), 3 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index b112efc..b265d8e 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2234,7 +2234,7 @@ into the hash PTE second double word).
4.75 KVM_IRQFD
Capability: KVM_CAP_IRQFD
-Architectures: x86 s390
+Architectures: x86 s390 arm arm64
Type: vm ioctl
Parameters: struct kvm_irqfd (in)
Returns: 0 on success, -1 on error
@@ -2260,6 +2260,10 @@ Note that closing the resamplefd is not sufficient to disable the
irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment
and need not be specified with KVM_IRQFD_FLAG_DEASSIGN.
+On ARM/ARM64, the gsi field in the kvm_irqfd struct specifies the Shared
+Peripheral Interrupt (SPI) index, such that the GIC interrupt ID is
+given by gsi + 32.
+
4.76 KVM_PPC_ALLOCATE_HTAB
Capability: KVM_CAP_PPC_ALLOC_HTAB
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 @@ struct kvm_arch_memory_slot {
/* 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 @@ config KVM
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_init.o := -Wa,-march=armv7-a$(plus_virt)
AFLAGS_interrupts.o := -Wa,-march=armv7-a$(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 $(KVM)/eventfd.o
obj-y += kvm-arm.o init.o interrupts.o
obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 5e893eb..cc96619 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -171,6 +171,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
int r;
switch (ext) {
case KVM_CAP_IRQCHIP:
+ case KVM_CAP_IRQFD:
case KVM_CAP_DEVICE_CTRL:
case KVM_CAP_USER_MEMORY:
case KVM_CAP_SYNC_MMU:
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 3ef77a4..c154c0b 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -191,6 +191,9 @@ struct kvm_arch_memory_slot {
/* Highest supported SPI, from VGIC_NR_IRQS */
#define KVM_ARM_IRQ_GIC_MAX 127
+/* One single KVM irqchip, ie. the VGIC */
+#define KVM_NR_IRQCHIPS 1
+
/* PSCI interface */
#define KVM_PSCI_FN_BASE 0x95c1ba5e
#define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n))
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 05f56ce..5105e29 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -28,6 +28,8 @@ config KVM
select KVM_ARM_HOST
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
select SRCU
+ select HAVE_KVM_EVENTFD
+ select HAVE_KVM_IRQFD
---help---
Support hosting virtualized guest machines.
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index c92b26a..b22c636 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -11,7 +11,7 @@ ARM=../../../arch/arm/kvm
obj-$(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
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 897c849..c000e97 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -31,6 +31,7 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
+#include <trace/events/kvm.h>
/*
* How the whole thing works (courtesy of Christoffer Dall):
@@ -1083,6 +1084,7 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
u32 status = vgic_get_interrupt_status(vcpu);
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
bool level_pending = false;
+ struct kvm *kvm = vcpu->kvm;
kvm_debug("STATUS = %08x\n", status);
@@ -1118,6 +1120,17 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
*/
vgic_dist_irq_clear_soft_pend(vcpu, vlr.irq);
+ /*
+ * kvm_notify_acked_irq calls kvm_set_irq()
+ * to reset the IRQ level. Need to release the
+ * lock for kvm_set_irq to grab it.
+ */
+ spin_unlock(&dist->lock);
+
+ kvm_notify_acked_irq(kvm, 0,
+ vlr.irq - VGIC_NR_PRIVATE_IRQS);
+ spin_lock(&dist->lock);
+
/* Any additional pending interrupt? */
if (vgic_dist_irq_get_level(vcpu, vlr.irq)) {
vgic_cpu_irq_set(vcpu, vlr.irq);
@@ -1913,3 +1926,38 @@ out_free_irq:
free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus());
return ret;
}
+
+int kvm_irq_map_gsi(struct kvm *kvm,
+ struct kvm_kernel_irq_routing_entry *entries,
+ int gsi)
+{
+ return gsi;
+}
+
+int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
+{
+ return pin;
+}
+
+int kvm_set_irq(struct kvm *kvm, int irq_source_id,
+ u32 irq, int level, bool line_status)
+{
+ unsigned int spi = irq + VGIC_NR_PRIVATE_IRQS;
+
+ trace_kvm_set_irq(irq, level, irq_source_id);
+
+ BUG_ON(!vgic_initialized(kvm));
+
+ if (spi > kvm->arch.vgic.nr_irqs)
+ return -EINVAL;
+ return kvm_vgic_inject_irq(kvm, 0, spi, level);
+
+}
+
+/* MSI not implemented yet */
+int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
+ struct kvm *kvm, int irq_source_id,
+ int level, bool line_status)
+{
+ return 0;
+}
--
2.1.4
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