Mark Rutland <mark.rutland@xxxxxxx> writes:
> On Fri, May 15, 2015 at 03:27:06PM +0100, Alex Bennée wrote:
>> This commit defines the API headers for guest debugging. There are two
>> architecture specific debug structures:
>>
>> - kvm_guest_debug_arch, allows us to pass in HW debug registers
>> - kvm_debug_exit_arch, signals exception and possible faulting address
>>
>> The type of debugging being used is controlled by the architecture
>> specific control bits of the kvm_guest_debug->control flags in the ioctl
>> structure.
>>
>> Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
>> Reviewed-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
>> Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
>> Acked-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
>>
>> ---
>> v2
>> - expose hsr and pc directly to user-space
>> v3
>> - s/control/controlled/ in commit message
>> - add v8 to ARM ARM comment (ARM Architecture Reference Manual)
>> - add rb tag
>> - rm pc, add far
>> - re-word comments on alignment
>> - rename KVM_ARM_NDBG_REGS -> KVM_ARM_MAX_DBG_REGS
>> v4
>> - now uses common HW/SW BP define
>> - add a-b-tag
>> - use u32 for control regs
>>
>> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
>> index d268320..8796610 100644
>> --- a/arch/arm64/include/uapi/asm/kvm.h
>> +++ b/arch/arm64/include/uapi/asm/kvm.h
>> @@ -100,10 +100,28 @@ struct kvm_sregs {
>> struct kvm_fpu {
>> };
>>
>> +/*
>> + * See v8 ARM ARM D7.3: Debug Registers
>> + *
>> + * The control registers are architecturally defined as 32 bits but are
>> + * stored as 64 bit values alongside the value registers. This is done
>
> Stale comment? They're stored as __u32 below.
Gah yes it is.
> It's possible that the registers could grow in future as happened in the
> case of CLIDR_EL1, so it might be worth treating system registers
> generally as u64 values.
Really? I mean the existing debug *control* registers have reserved bits
24-31 so there is space for expansion.
>
> Mark.
>
>> + * to keep the copying of these values into the vcpu context simple as
>> + * everything is 64 bit aligned (see DBGBCR0_EL1 onwards in kvm_asm.h).
>> + *
>> + * The architectural limit is 16 debug registers of each type although
>> + * in practice there are usually less (see ID_AA64DFR0_EL1).
>> + */
>> +#define KVM_ARM_MAX_DBG_REGS 16
>> struct kvm_guest_debug_arch {
>> + __u32 dbg_bcr[KVM_ARM_MAX_DBG_REGS];
>> + __u64 dbg_bvr[KVM_ARM_MAX_DBG_REGS];
>> + __u32 dbg_wcr[KVM_ARM_MAX_DBG_REGS];
>> + __u64 dbg_wvr[KVM_ARM_MAX_DBG_REGS];
>> };
>>
>> struct kvm_debug_exit_arch {
>> + __u32 hsr;
>> + __u64 far;
>> };
>>
>> struct kvm_sync_regs {
>> --
>> 2.3.5
>>
>> _______________________________________________
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>> kvmarm@xxxxxxxxxxxxxxxxxxxxx
>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
--
Alex Bennée
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