[PATCH v3] ARM: KVM: add irqfd support
Eric Auger
eric.auger at linaro.org
Mon Sep 1 01:53:04 PDT 2014
This patch enables irqfd on ARM.
irqfd framework enables to inject a virtual IRQ into a guest upon an
eventfd trigger. User-side uses KVM_IRQFD VM ioctl to provide KVM with
a kvm_irqfd struct that associates a VM, an eventfd, a virtual IRQ number
(aka. the gsi). When an actor signals the eventfd (typically a VFIO
platform driver), the kvm irqfd subsystem injects the provided virtual
IRQ into the guest.
Resamplefd also is supported for level sensitive interrupts, ie. the
user can provide another eventfd that is triggered when the completion
of the virtual IRQ (gsi) is detected by the GIC.
The gsi must correspond to a shared peripheral interrupt (SPI), ie the
GIC interrupt ID is gsi+32.
this patch enables CONFIG_HAVE_KVM_EVENTFD and CONFIG_HAVE_KVM_IRQFD.
CONFIG_HAVE_KVM_IRQCHIP is removed. No IRQ routing table is used
(irqchip.c and irqcomm.c are not used).
Both KVM_CAP_IRQFD & KVM_CAP_IRQFD_RESAMPLE capabilities are exposed
Signed-off-by: Eric Auger <eric.auger at linaro.org>
---
This patch serie deprecates the previous serie featuring GSI routing
(https://patches.linaro.org/32261/)
The patch serie has the following dependencies:
- arm/arm64: KVM: Various VGIC cleanups and improvements
https://lists.cs.columbia.edu/pipermail/kvmarm/2014-June/009979.html
- "KVM: EVENTFD: remove inclusion of irq.h"
All pieces can be found on git://git.linaro.org/people/eric.auger/linux.git
branch irqfd_norouting_integ_v3
This work was tested with Calxeda Midway xgmac main interrupt with
qemu-system-arm and QEMU VFIO platform device.
v2 -> v3:
- removal of irq.h from eventfd.c put in a separate patch to increase
visibility
- properly expose KVM_CAP_IRQFD capability in arm.c
- remove CONFIG_HAVE_KVM_IRQCHIP meaningfull only if irq_comm.c is used
v1 -> v2:
- rebase on 3.17rc1
- move of the dist unlock in process_maintenance
- remove of dist lock in __kvm_vgic_sync_hwstate
- rewording of the commit message (add resamplefd reference)
- remove irq.h
---
Documentation/virtual/kvm/api.txt | 5 +++-
arch/arm/include/uapi/asm/kvm.h | 3 +++
arch/arm/kvm/Kconfig | 4 +--
arch/arm/kvm/Makefile | 2 +-
arch/arm/kvm/arm.c | 3 +++
virt/kvm/arm/vgic.c | 56 ++++++++++++++++++++++++++++++++++++---
6 files changed, 65 insertions(+), 8 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index beae3fd..8118b12 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2204,7 +2204,7 @@ into the hash PTE second double word).
4.75 KVM_IRQFD
Capability: KVM_CAP_IRQFD
-Architectures: x86 s390
+Architectures: x86 s390 arm
Type: vm ioctl
Parameters: struct kvm_irqfd (in)
Returns: 0 on success, -1 on error
@@ -2230,6 +2230,9 @@ 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 injected must be a shared peripheral interrupt (SPI).
+This means the programmed GIC interrupt ID is 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 e6ebdd3..3034c66 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -194,6 +194,9 @@ 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 466bd29..e519a40 100644
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -24,6 +24,7 @@ config KVM
select KVM_MMIO
select KVM_ARM_HOST
depends on ARM_VIRT_EXT && ARM_LPAE
+ select HAVE_KVM_EVENTFD
---help---
Support hosting virtualized guest machines. You will also
need to select one or more of the processor modules below.
@@ -55,7 +56,7 @@ config KVM_ARM_MAX_VCPUS
config KVM_ARM_VGIC
bool "KVM support for Virtual GIC"
depends on KVM_ARM_HOST && OF
- select HAVE_KVM_IRQCHIP
+ select HAVE_KVM_IRQFD
default y
---help---
Adds support for a hardware assisted, in-kernel GIC emulation.
@@ -63,7 +64,6 @@ config KVM_ARM_VGIC
config KVM_ARM_TIMER
bool "KVM support for Architected Timers"
depends on KVM_ARM_VGIC && ARM_ARCH_TIMER
- select HAVE_KVM_IRQCHIP
default y
---help---
Adds support for the Architected Timers in virtual machines
diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
index f7057ed..859db09 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 a99e0cd..6ba454a 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -181,6 +181,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_IRQCHIP:
r = vgic_present;
break;
+#ifdef CONFIG_HAVE_KVM_IRQFD
+ case KVM_CAP_IRQFD:
+#endif
case KVM_CAP_DEVICE_CTRL:
case KVM_CAP_USER_MEMORY:
case KVM_CAP_SYNC_MMU:
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 7164d2e..586bd11 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1334,7 +1334,10 @@ epilog:
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;
+ int is_assigned_irq;
kvm_debug("STATUS = %08x\n", status);
@@ -1351,6 +1354,7 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
struct vgic_lr vlr = vgic_get_lr(vcpu, lr);
BUG_ON(vgic_irq_is_edge(vcpu, vlr.irq));
+ spin_lock(&dist->lock);
vgic_irq_clear_queued(vcpu, vlr.irq);
WARN_ON(vlr.state & LR_STATE_MASK);
vlr.state = 0;
@@ -1363,6 +1367,18 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
* interrupt.
*/
vgic_dist_irq_clear_soft_pend(vcpu, vlr.irq);
+ spin_unlock(&dist->lock);
+
+ is_assigned_irq = kvm_irq_has_notifier(kvm, 0,
+ vlr.irq - VGIC_NR_PRIVATE_IRQS);
+
+ if (is_assigned_irq) {
+ kvm_debug("EOI irqchip routed vIRQ %d\n",
+ vlr.irq);
+ 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)) {
@@ -1377,6 +1393,8 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
vgic_cpu_irq_clear(vcpu, vlr.irq);
}
+ spin_unlock(&dist->lock);
+
/*
* Despite being EOIed, the LR may not have
* been marked as empty.
@@ -1441,14 +1459,10 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
{
- struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
-
if (!irqchip_in_kernel(vcpu->kvm))
return;
- spin_lock(&dist->lock);
__kvm_vgic_sync_hwstate(vcpu);
- spin_unlock(&dist->lock);
}
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
@@ -2183,3 +2197,37 @@ struct kvm_device_ops kvm_arm_vgic_v2_ops = {
.get_attr = vgic_get_attr,
.has_attr = vgic_has_attr,
};
+
+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)
+{
+ int r = -EINVAL;
+ unsigned int spi = irq + VGIC_NR_PRIVATE_IRQS;
+
+ if (spi > KVM_ARM_IRQ_GIC_MAX)
+ return r;
+
+ kvm_debug("Inject irqchip routed vIRQ %d\n", irq);
+ r = kvm_vgic_inject_irq(kvm, 0, spi, level);
+ return r;
+}
+
+/* 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;
+}
--
1.9.1
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