KVM: arm/arm64: enable irqchip routing

This patch adds compilation and link against irqchip.

On ARM, irqchip routing is not really useful since there is
a single irqchip. However main motivation behind using irqchip
code is to enable MSI routing code. With the support of in-kernel
GICv3 ITS emulation, it now seems to be a MUST HAVE requirement.

Functions previously implemented in vgic.c and substitute
to more complex irqchip implementation are removed:

- kvm_send_userspace_msi
- kvm_irq_map_chip_pin
- kvm_set_irq
- kvm_irq_map_gsi.

They implemented a kernel default identity GSI routing. This is now
replaced by user-side provided routing.

Routing standard hooks are now implemented in vgic:
- kvm_set_routing_entry
- kvm_set_irq
- kvm_set_msi

Both HAVE_KVM_IRQCHIP and HAVE_KVM_IRQ_ROUTING are defined.
KVM_CAP_IRQ_ROUTING is advertised and KVM_SET_GSI_ROUTING is allowed.

MSI routing is not yet allowed.

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

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 30941398f059356f1b8c4a993ff80b6db241f9d8..459da3187b86e98fecb2a6059c77bf74a3e7e10f 100644 (file)
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1421,13 +1421,16 @@ KVM_ASSIGN_DEV_IRQ. Partial deassignment of host or guest IRQ is allowed.
 4.52 KVM_SET_GSI_ROUTING
 
 Capability: KVM_CAP_IRQ_ROUTING
-Architectures: x86 s390
+Architectures: x86 s390 arm arm64
 Type: vm ioctl
 Parameters: struct kvm_irq_routing (in)
 Returns: 0 on success, -1 on error
 
 Sets the GSI routing table entries, overwriting any previously set entries.
 
+On arm/arm64, GSI routing has the following limitation:
+- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD.
+
 struct kvm_irq_routing {
        __u32 nr;
        __u32 flags;
@@ -2339,9 +2342,10 @@ 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.
+On arm/arm64, gsi routing being supported, the following can happen:
+- in case no routing entry is associated to this gsi, injection fails
+- in case the gsi is associated to an irqchip routing entry,
+  irqchip.pin + 32 corresponds to the injected SPI ID.
 
 4.76 KVM_PPC_ALLOCATE_HTAB
 

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 56cac05c0fa64ac8678cf67b546be0d05c744598..9ced1470163cdbe66c90e31291d615a0974abc0e 100644 (file)
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -42,6 +42,8 @@
 
 #define KVM_VCPU_MAX_FEATURES 2
 
+#define KVM_IRQCHIP_NUM_PINS 988 /* 1020 -32 is the number of SPI */
+
 #include <kvm/arm_vgic.h>
 
 u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);

diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
index bfb915d0566566978b8e51c5ae7c93adfad04d0f..151e710e91edc6491de283e9184a804c2d40d235 100644 (file)
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@@ -31,6 +31,8 @@ config KVM
        select KVM_VFIO
        select HAVE_KVM_EVENTFD
        select HAVE_KVM_IRQFD
+       select HAVE_KVM_IRQCHIP
+       select HAVE_KVM_IRQ_ROUTING
        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 c5eef02c52ba76b24ac7fa996e04a988d674e751..1a8f48aa2e1de00c7fc5bc52e802246f1240c229 100644 (file)
--- 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)/eventfd.o $(KVM)/vfio.o
+kvm-arm-y = $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o $(KVM)/vfio.o $(KVM)/irqchip.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/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 8d78a72dc32bb188ce6cbce79042ae5e536dd5fb..ff007cf13740f07caa656c6ff35e29252ee26c3c 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -44,6 +44,7 @@
 #include <kvm/arm_arch_timer.h>
 
 #define KVM_VCPU_MAX_FEATURES 3
+#define KVM_IRQCHIP_NUM_PINS 988 /* 1020 -32 is the number of SPI */
 
 int __attribute_const__ kvm_target_cpu(void);
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu);

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index ff9722f26e342193a90846c150ec6ccc304048ff..1a9900dc80860c25775580f8ca5bbbb45a6db0d7 100644 (file)
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -32,6 +32,8 @@ config KVM
        select HAVE_KVM_EVENTFD
        select HAVE_KVM_IRQFD
        select HAVE_KVM_MSI
+       select HAVE_KVM_IRQCHIP
+       select HAVE_KVM_IRQ_ROUTING
        ---help---
          Support hosting virtualized guest machines.
 

diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 9803307899da2735e7e95f563c1dbbd58e71d3f8..90a0845771b523dd053c65e8431070d092e52d70 100644 (file)
--- 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)/eventfd.o $(KVM)/vfio.o
+kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o $(KVM)/vfio.o $(KVM)/irqchip.o
 kvm-$(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/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index f50081c4b652e8a80e47984fba08182ba9816cf9..1b370a05d0b07b05f7a433d318c44b63a0a78764 100644 (file)
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -375,6 +375,4 @@ static inline int vgic_v3_probe(struct device_node *vgic_node,
 }
 #endif
 
-int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi);
-
 #endif

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 081a1efa421a2076934e05a70f90d36cdb4807d4..e38a0de7a42d710032bfc0c7d622483be6e0a758 100644 (file)
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -2215,42 +2215,65 @@ out_free_irq:
        return ret;
 }
 
-int kvm_irq_map_gsi(struct kvm *kvm,
-                   struct kvm_kernel_irq_routing_entry *entries,
-                   int gsi)
+int vgic_irqfd_set_irq(struct kvm_kernel_irq_routing_entry *e,
+                       struct kvm *kvm, int irq_source_id,
+                       int level, bool line_status)
 {
-       return 0;
-}
-
-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;
+       unsigned int spi_id = e->irqchip.pin + VGIC_NR_PRIVATE_IRQS;
 
-       trace_kvm_set_irq(irq, level, irq_source_id);
+       trace_kvm_set_irq(spi_id, level, irq_source_id);
 
        BUG_ON(!vgic_initialized(kvm));
 
-       return kvm_vgic_inject_irq(kvm, 0, spi, level);
+       if (spi_id > min(kvm->arch.vgic.nr_irqs, 1020))
+               return -EINVAL;
+       return kvm_vgic_inject_irq(kvm, 0, spi_id, level);
+}
+
+/**
+ * Populates a kvm routing entry from a user routing entry
+ * @e: kvm internal formatted entry
+ * @ue: user api formatted entry
+ * return 0 on success, -EINVAL on errors.
+ */
+int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
+                         const struct kvm_irq_routing_entry *ue)
+{
+       int r = -EINVAL;
+
+       switch (ue->type) {
+       case KVM_IRQ_ROUTING_IRQCHIP:
+               e->set = vgic_irqfd_set_irq;
+               e->irqchip.irqchip = ue->u.irqchip.irqchip;
+               e->irqchip.pin = ue->u.irqchip.pin;
+               if ((e->irqchip.pin >= KVM_IRQCHIP_NUM_PINS) ||
+                   (e->irqchip.irqchip >= KVM_NR_IRQCHIPS))
+                       goto out;
+               break;
+       default:
+               goto out;
+       }
+       r = 0;
+out:
+       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;
-}
+       struct kvm_msi msi;
+
+       msi.address_lo = e->msi.address_lo;
+       msi.address_hi = e->msi.address_hi;
+       msi.data = e->msi.data;
+       if (e->type == KVM_IRQ_ROUTING_EXTENDED_MSI) {
+               msi.devid = e->devid;
+               msi.flags = KVM_MSI_VALID_DEVID;
+       }
 
-int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
-{
        if (kvm->arch.vgic.vm_ops.inject_msi)
-               return kvm->arch.vgic.vm_ops.inject_msi(kvm, msi);
+               return kvm->arch.vgic.vm_ops.inject_msi(kvm, &msi);
        else
                return -ENODEV;
 }

diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index e678f8a1ef25e82a153ae55f395821eeb819c824..f26cadd52ad8d5fc4078294db17e17f132bb0e68 100644 (file)
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -29,7 +29,9 @@
 #include <linux/srcu.h>
 #include <linux/export.h>
 #include <trace/events/kvm.h>
+#if !defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
 #include "irq.h"
+#endif
 
 struct kvm_irq_routing_table {
        int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];