[PATCH 09/15] KVM: ARM: Inject IRQs and FIQs from userspace

[Christoffer Dall]

On Tue, Sep 25, 2012 at 11:55 AM, Will Deacon <will.deacon at arm.com> wrote:
> On Sat, Sep 15, 2012 at 04:35:27PM +0100, Christoffer Dall wrote:
>> diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
>> index a13b582..131e632 100644
>> --- a/arch/arm/include/asm/kvm.h
>> +++ b/arch/arm/include/asm/kvm.h
>> @@ -22,6 +22,7 @@
>>  #include <asm/types.h>
>>
>>  #define __KVM_HAVE_GUEST_DEBUG
>> +#define __KVM_HAVE_IRQ_LINE
>>
>>  #define KVM_REG_SIZE(id)                                             \
>>       (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
>> @@ -85,4 +86,24 @@ struct kvm_reg_list {
>>  #define KVM_REG_ARM_CORE             (0x0010 << KVM_REG_ARM_COPROC_SHIFT)
>>  #define KVM_REG_ARM_CORE_REG(name)   (offsetof(struct kvm_regs, name) / 4)
>>
>> +/* KVM_IRQ_LINE irq field index values */
>> +#define KVM_ARM_IRQ_TYPE_SHIFT               24
>> +#define KVM_ARM_IRQ_TYPE_MASK                0xff
>> +#define KVM_ARM_IRQ_VCPU_SHIFT               16
>> +#define KVM_ARM_IRQ_VCPU_MASK                0xff
>> +#define KVM_ARM_IRQ_NUM_SHIFT                0
>> +#define KVM_ARM_IRQ_NUM_MASK         0xffff
>> +
>> +/* irq_type field */
>> +#define KVM_ARM_IRQ_TYPE_CPU         0
>> +#define KVM_ARM_IRQ_TYPE_SPI         1
>> +#define KVM_ARM_IRQ_TYPE_PPI         2
>> +
>> +/* out-of-kernel GIC cpu interrupt injection irq_number field */
>> +#define KVM_ARM_IRQ_CPU_IRQ          0
>> +#define KVM_ARM_IRQ_CPU_FIQ          1
>> +
>> +/* Highest supported SPI, from VGIC_NR_IRQS */
>> +#define KVM_ARM_IRQ_GIC_MAX          127
>
> This define, and those referring to PPIs and SPIs sound highly GIC-specific.
> Is that really appropriate for kvm.h? Do you mandate a single GIC as the
> only interrupt controller?
>

you can add a another gic with another in-kernel gic emulation if
someone makes such one that's different from the vgic specifications
by defining another irq type.

devices must interact with a gic available in the kernel, so I think
referring to PPIs and SPIs is very appropriate in kvm.h for a user
space device emulation that must inject either a PPI or an SPI.

We can call them TYPE_GIC_V2_XXX or something like that if you feel
this is cleaner.

>> diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
>> index 6e46541..0f641c1 100644
>> --- a/arch/arm/include/asm/kvm_arm.h
>> +++ b/arch/arm/include/asm/kvm_arm.h
>> @@ -74,6 +74,7 @@
>>  #define HCR_GUEST_MASK (HCR_TSC | HCR_TSW | HCR_TWI | HCR_VM | HCR_BSU_IS | \
>>                       HCR_FB | HCR_TAC | HCR_AMO | HCR_IMO | HCR_FMO | \
>>                       HCR_SWIO | HCR_TIDCP)
>> +#define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF)
>>
>>  /* Hyp System Control Register (HSCTLR) bits */
>>  #define HSCTLR_TE    (1 << 30)
>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
>> index b97ebd0..8a87fc7 100644
>> --- a/arch/arm/kvm/arm.c
>> +++ b/arch/arm/kvm/arm.c
>> @@ -24,6 +24,7 @@
>>  #include <linux/fs.h>
>>  #include <linux/mman.h>
>>  #include <linux/sched.h>
>> +#include <linux/kvm.h>
>>  #include <trace/events/kvm.h>
>>
>>  #define CREATE_TRACE_POINTS
>> @@ -271,6 +272,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
>>
>>  void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
>>  {
>> +     vcpu->cpu = cpu;
>>  }
>>
>>  void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
>> @@ -311,6 +313,74 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>>       return -EINVAL;
>>  }
>>
>> +static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
>> +{
>> +     int bit_index;
>> +     bool set;
>> +     unsigned long *ptr;
>> +
>> +     if (number == KVM_ARM_IRQ_CPU_IRQ)
>> +             bit_index = ffs(HCR_VI) - 1;
>> +     else /* KVM_ARM_IRQ_CPU_FIQ */
>> +             bit_index = ffs(HCR_VF) - 1;
>
> __ffs
>
fixed


-Christoffer