Patchwork [RFC,v2,4/4] arm: vgic device control api support

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Submitter Christoffer Dall
Date Sept. 26, 2013, 7:56 p.m.
Message ID <1380225373-22132-5-git-send-email-christoffer.dall@linaro.org>
Download mbox | patch
Permalink /patch/278255/
State New
Headers show

Comments

Christoffer Dall - Sept. 26, 2013, 7:56 p.m.
Support creating the ARM vgic device through the device control API and
setting the base address for the distributor and cpu interfaces in KVM
VMs using this API.

Because the older KVM_CREATE_IRQCHIP interface needs the irq chip to be
created prior to creating the VCPUs, we first test if we can use the
device control API in kvm_arch_irqchip_create (using the test flag from
the device control API).  If we cannot, it means we have to fall back to
KVM_CREATE_IRQCHIP and use the older ioctl at this point in time.  If
however, we can use the device control API, we don't do anything and
wait until the arm_gic_kvm driver initializes and let that use the
device control API.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

---
Changelog[v2]:
 - Moved dev_fd into GICState
 - Proper error handling in kvm_arm_gic_realize
 - Coding style and other minor fixes
---
 hw/intc/arm_gic_kvm.c  |   22 +++++++++++++++++--
 hw/intc/gic_internal.h |    1 +
 target-arm/kvm.c       |   55 ++++++++++++++++++++++++++++++++++++++++++------
 target-arm/kvm_arm.h   |   18 ++++++++++------
 4 files changed, 81 insertions(+), 15 deletions(-)
Peter Maydell - Oct. 14, 2013, 1:49 p.m.
On 26 September 2013 20:56, Christoffer Dall
<christoffer.dall@linaro.org> wrote:
> Support creating the ARM vgic device through the device control API and
> setting the base address for the distributor and cpu interfaces in KVM
> VMs using this API.
>
> Because the older KVM_CREATE_IRQCHIP interface needs the irq chip to be
> created prior to creating the VCPUs, we first test if we can use the
> device control API in kvm_arch_irqchip_create (using the test flag from
> the device control API).  If we cannot, it means we have to fall back to
> KVM_CREATE_IRQCHIP and use the older ioctl at this point in time.  If
> however, we can use the device control API, we don't do anything and
> wait until the arm_gic_kvm driver initializes and let that use the
> device control API.
>
> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

> +    if (ret < 0) {
> +            fprintf(stderr, "Failed to set device address: %s\n",
> +                    strerror(-ret));
> +            abort();
> +    }

Your indentation here is wrong.

> diff --git a/target-arm/kvm_arm.h b/target-arm/kvm_arm.h
> index 5d14887..ea1805a 100644
> --- a/target-arm/kvm_arm.h
> +++ b/target-arm/kvm_arm.h
> @@ -18,16 +18,22 @@
>   * kvm_arm_register_device:
>   * @mr: memory region for this device
>   * @devid: the KVM device ID
> + * @type: device control API device type
> + * @group: device control API group for setting addresses
> + * @attr: device control API address type
> + * @dev_fd: device control device file descriptor (or -1 if not supported)

This adds documentation for four new parameters...

> -void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid);
> +void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid, uint64_t group,
> +                             uint64_t attr, int dev_fd);

...but the prototype only adds three (no new 'type'
param).

Looks good otherwise.

-- PMM

Patch

diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c
index f713975..158f047 100644
--- a/hw/intc/arm_gic_kvm.c
+++ b/hw/intc/arm_gic_kvm.c
@@ -97,6 +97,7 @@  static void kvm_arm_gic_realize(DeviceState *dev, Error **errp)
     GICState *s = KVM_ARM_GIC(dev);
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
     KVMARMGICClass *kgc = KVM_ARM_GIC_GET_CLASS(s);
+    int ret;
 
     kgc->parent_realize(dev, errp);
     if (error_is_set(errp)) {
@@ -119,13 +120,27 @@  static void kvm_arm_gic_realize(DeviceState *dev, Error **errp)
     for (i = 0; i < s->num_cpu; i++) {
         sysbus_init_irq(sbd, &s->parent_irq[i]);
     }
+
+    /* Try to create the device via the device control API */
+    s->dev_fd = -1;
+    ret = kvm_create_device(kvm_state, KVM_DEV_TYPE_ARM_VGIC_V2, false);
+    if (ret >= 0) {
+        s->dev_fd = ret;
+    } else if (ret != -ENODEV) {
+        error_setg_errno(errp, -ret, "error creating in-kernel VGIC");
+        return;
+    }
+
     /* Distributor */
     memory_region_init_reservation(&s->iomem, OBJECT(s),
                                    "kvm-gic_dist", 0x1000);
     sysbus_init_mmio(sbd, &s->iomem);
     kvm_arm_register_device(&s->iomem,
                             (KVM_ARM_DEVICE_VGIC_V2 << KVM_ARM_DEVICE_ID_SHIFT)
-                            | KVM_VGIC_V2_ADDR_TYPE_DIST);
+                            | KVM_VGIC_V2_ADDR_TYPE_DIST,
+                            KVM_DEV_ARM_VGIC_GRP_ADDR,
+                            KVM_VGIC_V2_ADDR_TYPE_DIST,
+                            s->dev_fd);
     /* CPU interface for current core. Unlike arm_gic, we don't
      * provide the "interface for core #N" memory regions, because
      * cores with a VGIC don't have those.
@@ -135,7 +150,10 @@  static void kvm_arm_gic_realize(DeviceState *dev, Error **errp)
     sysbus_init_mmio(sbd, &s->cpuiomem[0]);
     kvm_arm_register_device(&s->cpuiomem[0],
                             (KVM_ARM_DEVICE_VGIC_V2 << KVM_ARM_DEVICE_ID_SHIFT)
-                            | KVM_VGIC_V2_ADDR_TYPE_CPU);
+                            | KVM_VGIC_V2_ADDR_TYPE_CPU,
+                            KVM_DEV_ARM_VGIC_GRP_ADDR,
+                            KVM_VGIC_V2_ADDR_TYPE_CPU,
+                            s->dev_fd);
 }
 
 static void kvm_arm_gic_class_init(ObjectClass *klass, void *data)
diff --git a/hw/intc/gic_internal.h b/hw/intc/gic_internal.h
index 1426437..b3788a8 100644
--- a/hw/intc/gic_internal.h
+++ b/hw/intc/gic_internal.h
@@ -99,6 +99,7 @@  typedef struct GICState {
     MemoryRegion cpuiomem[NCPU+1]; /* CPU interfaces */
     uint32_t num_irq;
     uint32_t revision;
+    int dev_fd; /* kvm device fd if backed by kvm vgic support */
 } GICState;
 
 /* The special cases for the revision property: */
diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index b92e00d..747ff70 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -184,8 +184,10 @@  out:
  */
 typedef struct KVMDevice {
     struct kvm_arm_device_addr kda;
+    struct kvm_device_attr kdattr;
     MemoryRegion *mr;
     QSLIST_ENTRY(KVMDevice) entries;
+    int dev_fd;
 } KVMDevice;
 
 static QSLIST_HEAD(kvm_devices_head, KVMDevice) kvm_devices_head;
@@ -219,6 +221,29 @@  static MemoryListener devlistener = {
     .region_del = kvm_arm_devlistener_del,
 };
 
+static void kvm_arm_set_device_addr(KVMDevice *kd)
+{
+    struct kvm_device_attr *attr = &kd->kdattr;
+    int ret;
+
+    /* If the device control API is available and we have a device fd on the
+     * KVMDevice struct, let's use the newer API
+     */
+    if (kd->dev_fd >= 0) {
+        uint64_t addr = kd->kda.addr;
+        attr->addr = (uintptr_t)&addr;
+        ret = kvm_device_ioctl(kd->dev_fd, KVM_SET_DEVICE_ATTR, attr);
+    } else {
+        ret = kvm_vm_ioctl(kvm_state, KVM_ARM_SET_DEVICE_ADDR, &kd->kda);
+    }
+
+    if (ret < 0) {
+            fprintf(stderr, "Failed to set device address: %s\n",
+                    strerror(-ret));
+            abort();
+    }
+}
+
 static void kvm_arm_machine_init_done(Notifier *notifier, void *data)
 {
     KVMDevice *kd, *tkd;
@@ -226,12 +251,7 @@  static void kvm_arm_machine_init_done(Notifier *notifier, void *data)
     memory_listener_unregister(&devlistener);
     QSLIST_FOREACH_SAFE(kd, &kvm_devices_head, entries, tkd) {
         if (kd->kda.addr != -1) {
-            if (kvm_vm_ioctl(kvm_state, KVM_ARM_SET_DEVICE_ADDR,
-                             &kd->kda) < 0) {
-                fprintf(stderr, "KVM_ARM_SET_DEVICE_ADDRESS failed: %s\n",
-                        strerror(errno));
-                abort();
-            }
+            kvm_arm_set_device_addr(kd);
         }
         memory_region_unref(kd->mr);
         g_free(kd);
@@ -242,7 +262,8 @@  static Notifier notify = {
     .notify = kvm_arm_machine_init_done,
 };
 
-void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid)
+void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid, uint64_t group,
+                             uint64_t attr, int dev_fd)
 {
     KVMDevice *kd;
 
@@ -258,6 +279,10 @@  void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid)
     kd->mr = mr;
     kd->kda.id = devid;
     kd->kda.addr = -1;
+    kd->kdattr.flags = 0;
+    kd->kdattr.group = group;
+    kd->kdattr.attr = attr;
+    kd->dev_fd = dev_fd;
     QSLIST_INSERT_HEAD(&kvm_devices_head, kd, entries);
     memory_region_ref(kd->mr);
 }
@@ -647,3 +672,19 @@  void kvm_arch_remove_all_hw_breakpoints(void)
 void kvm_arch_init_irq_routing(KVMState *s)
 {
 }
+
+int kvm_arch_irqchip_create(KVMState *s)
+{
+    int ret;
+
+    /* If we can create the VGIC using the newer device control API, we
+     * let the device do this when it initializes itself, otherwise we
+     * fall back to the old API */
+
+    ret = kvm_create_device(s, KVM_DEV_TYPE_ARM_VGIC_V2, true);
+    if (ret == 0) {
+        return 1;
+    }
+
+    return 0;
+}
diff --git a/target-arm/kvm_arm.h b/target-arm/kvm_arm.h
index 5d14887..ea1805a 100644
--- a/target-arm/kvm_arm.h
+++ b/target-arm/kvm_arm.h
@@ -18,16 +18,22 @@ 
  * kvm_arm_register_device:
  * @mr: memory region for this device
  * @devid: the KVM device ID
+ * @type: device control API device type
+ * @group: device control API group for setting addresses
+ * @attr: device control API address type
+ * @dev_fd: device control device file descriptor (or -1 if not supported)
  *
  * Remember the memory region @mr, and when it is mapped by the
  * machine model, tell the kernel that base address using the
- * KVM_SET_DEVICE_ADDRESS ioctl. @devid should be the ID of
- * the device as defined by KVM_SET_DEVICE_ADDRESS.
- * The machine model may map and unmap the device multiple times;
- * the kernel will only be told the final address at the point
- * where machine init is complete.
+ * KVM_ARM_SET_DEVICE_ADDRESS ioctl or the newer device control API.  @devid
+ * should be the ID of the device as defined by KVM_ARM_SET_DEVICE_ADDRESS or
+ * the arm-vgic device in the device control API.
+ * The machine model may map
+ * and unmap the device multiple times; the kernel will only be told the final
+ * address at the point where machine init is complete.
  */
-void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid);
+void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid, uint64_t group,
+                             uint64_t attr, int dev_fd);
 
 /**
  * write_list_to_kvmstate: