[RFC PATCH 3/5] KVM: ARM VGIC add kvm_io_bus_ frontend
Nikolay Nikolaev
n.nikolaev at virtualopensystems.com
Mon Nov 24 13:26:58 PST 2014
In io_mem_abort remove the call to vgic_handle_mmio. The target is to have
a single MMIO handling path - that is through the kvm_io_bus_ API.
Register a kvm_io_device in kvm_vgic_init on the whole vGIC MMIO region.
Both read and write calls are redirected to vgic_io_dev_access where
kvm_exit_mmio is composed to pass it to vm_ops.handle_mmio.
Signed-off-by: Nikolay Nikolaev <n.nikolaev at virtualopensystems.com>
---
arch/arm/kvm/mmio.c | 3 --
include/kvm/arm_vgic.h | 3 +-
virt/kvm/arm/vgic.c | 88 ++++++++++++++++++++++++++++++++++++++++--------
3 files changed, 74 insertions(+), 20 deletions(-)
diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
index 81230da..1c44a2b 100644
--- a/arch/arm/kvm/mmio.c
+++ b/arch/arm/kvm/mmio.c
@@ -227,9 +227,6 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
if (mmio.is_write)
mmio_write_buf(mmio.data, mmio.len, data);
- if (vgic_handle_mmio(vcpu, run, &mmio))
- return 1;
-
if (handle_kernel_mmio(vcpu, run, &mmio))
return 1;
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index e452ef7..d9b7d2a 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -233,6 +233,7 @@ struct vgic_dist {
unsigned long *irq_pending_on_cpu;
struct vgic_vm_ops vm_ops;
+ struct kvm_io_device *io_dev;
#endif
};
@@ -307,8 +308,6 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
bool level);
void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
-bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
- struct kvm_exit_mmio *mmio);
#define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel))
#define vgic_initialized(k) ((k)->arch.vgic.ready)
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 1213da5..3da1115 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -31,6 +31,9 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm.h>
+
+#include "iodev.h"
/*
* How the whole thing works (courtesy of Christoffer Dall):
@@ -775,28 +778,81 @@ bool vgic_handle_mmio_range(struct kvm_vcpu *vcpu, struct kvm_run *run,
return true;
}
-/**
- * vgic_handle_mmio - handle an in-kernel MMIO access for the GIC emulation
- * @vcpu: pointer to the vcpu performing the access
- * @run: pointer to the kvm_run structure
- * @mmio: pointer to the data describing the access
- *
- * returns true if the MMIO access has been performed in kernel space,
- * and false if it needs to be emulated in user space.
- * Calls the actual handling routine for the selected VGIC model.
- */
-bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
- struct kvm_exit_mmio *mmio)
+static int vgic_io_dev_access(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
+ gpa_t addr, int len, void *val, bool is_write)
{
- if (!irqchip_in_kernel(vcpu->kvm))
- return false;
+ struct kvm_exit_mmio mmio;
+ bool ret;
+
+ mmio = (struct kvm_exit_mmio) {
+ .phys_addr = addr,
+ .len = len,
+ .is_write = is_write,
+ };
+
+ if (is_write)
+ memcpy(mmio.data, val, len);
/*
* This will currently call either vgic_v2_handle_mmio() or
* vgic_v3_handle_mmio(), which in turn will call
* vgic_handle_mmio_range() defined above.
*/
- return vcpu->kvm->arch.vgic.vm_ops.handle_mmio(vcpu, run, mmio);
+ ret = vcpu->kvm->arch.vgic.vm_ops.handle_mmio(vcpu, vcpu->run, &mmio);
+
+ if (!is_write)
+ memcpy(val, mmio.data, len);
+
+ return ret ? 0 : 1;
+}
+
+static int vgic_io_dev_read(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
+ gpa_t addr, int len, void *val)
+{
+ return vgic_io_dev_access(vcpu, this, addr, len, val, false);
+}
+
+static int vgic_io_dev_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
+ gpa_t addr, int len, const void *val)
+{
+ return vgic_io_dev_access(vcpu, this, addr, len, (void *)val, true);
+}
+
+static const struct kvm_io_device_ops vgic_io_dev_ops = {
+ .read = vgic_io_dev_read,
+ .write = vgic_io_dev_write,
+};
+
+static int vgic_register_kvm_io_dev(struct kvm *kvm)
+{
+ struct kvm_io_device *dev;
+ int ret;
+
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ unsigned long base = dist->vgic_dist_base;
+
+ dev = kzalloc(sizeof(struct kvm_io_device), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ kvm_iodevice_init(dev, &vgic_io_dev_ops);
+
+ mutex_lock(&kvm->slots_lock);
+
+ ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
+ base, KVM_VGIC_V2_DIST_SIZE, dev);
+ if (ret < 0)
+ goto out_free_dev;
+ mutex_unlock(&kvm->slots_lock);
+
+ kvm->arch.vgic.io_dev = dev;
+
+ return 0;
+
+out_free_dev:
+ mutex_unlock(&kvm->slots_lock);
+ kfree(dev);
+ return ret;
}
static int vgic_nr_shared_irqs(struct vgic_dist *dist)
@@ -1545,6 +1601,8 @@ int kvm_vgic_init(struct kvm *kvm)
mutex_lock(&kvm->lock);
+ vgic_register_kvm_io_dev(kvm);
+
if (vgic_initialized(kvm))
goto out;
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