[RFC PATCH 3/5] KVM: ARM VGIC add kvm_io_bus_ frontend
Nikolay Nikolaev
n.nikolaev at virtualopensystems.com
Sat Nov 29 05:58:50 PST 2014
On Sat, Nov 29, 2014 at 9:14 AM, Shannon Zhao <zhaoshenglong at huawei.com> wrote:
> On 2014/11/25 5:26, Nikolay Nikolaev wrote:
>> 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);
>
> Should we consider GICv3? I think if applying this patch, it can not run well while creating a vGICv3 for guest.
Agree. Christofer also pointed this out. Will select the dist size
depending on the vgic_model.
Thanks.
Nikolay Nikolay
>
> Thanks,
> Shannon
>> + 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;
>>
>>
>> _______________________________________________
>> kvmarm mailing list
>> kvmarm at lists.cs.columbia.edu
>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>
>> .
>>
>
>
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