diff mbox

[v5,03/12] KVM: arm64: guest debug, define API headers

Message ID 1432891828-4816-4-git-send-email-alex.bennee@linaro.org
State New
Headers show

Commit Message

Alex Bennée May 29, 2015, 9:30 a.m. UTC
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@linaro.org>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>

---
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
v5
   - revert to have arch specific KVM_GUESTDBG_USE_SW/HW_BP
   - rm stale comments dbgctrl was stored as u64
---
 arch/arm64/include/uapi/asm/kvm.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

Comments

Christoffer Dall June 4, 2015, 11:07 a.m. UTC | #1
On Fri, May 29, 2015 at 10:30:19AM +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@linaro.org>
> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
> Reviewed-by: Andrew Jones <drjones@redhat.com>
> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>

I can re-confirm my ack despite the changes in v4, but this really is
borderline to keep exiting r-b and a-b tags around from previous patches
I would think, but ok.

-Christoffer

> 
> ---
> 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
> v5
>    - revert to have arch specific KVM_GUESTDBG_USE_SW/HW_BP
>    - rm stale comments dbgctrl was stored as u64
> ---
>  arch/arm64/include/uapi/asm/kvm.h | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index d268320..43758e7 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -100,12 +100,32 @@ struct kvm_sregs {
>  struct kvm_fpu {
>  };
>  
> +/*
> + * See v8 ARM ARM D7.3: Debug Registers
> + *
> + * 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;
>  };
>  
> +/*
> + * Architecture specific defines for kvm_guest_debug->control
> + */
> +
> +#define KVM_GUESTDBG_USE_SW_BP		(1 << 16)
> +#define KVM_GUESTDBG_USE_HW_BP		(1 << 17)
> +
>  struct kvm_sync_regs {
>  };
>  
> -- 
> 2.4.1
> 
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Alex Bennée June 4, 2015, 1:49 p.m. UTC | #2
Christoffer Dall <christoffer.dall@linaro.org> writes:

> On Fri, May 29, 2015 at 10:30:19AM +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@linaro.org>
>> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
>> Reviewed-by: Andrew Jones <drjones@redhat.com>
>> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
>
> I can re-confirm my ack despite the changes in v4, but this really is
> borderline to keep exiting r-b and a-b tags around from previous patches
> I would think, but ok.

I was wondering how much a patch has to change for the r-b tags to
become invalid. The meat of the API hasn't changed much though.

Drew/David,

Are you still happy with this patch?

>
> -Christoffer
>
>> 
>> ---
>> 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
>> v5
>>    - revert to have arch specific KVM_GUESTDBG_USE_SW/HW_BP
>>    - rm stale comments dbgctrl was stored as u64
>> ---
>>  arch/arm64/include/uapi/asm/kvm.h | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>> 
>> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
>> index d268320..43758e7 100644
>> --- a/arch/arm64/include/uapi/asm/kvm.h
>> +++ b/arch/arm64/include/uapi/asm/kvm.h
>> @@ -100,12 +100,32 @@ struct kvm_sregs {
>>  struct kvm_fpu {
>>  };
>>  
>> +/*
>> + * See v8 ARM ARM D7.3: Debug Registers
>> + *
>> + * 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;
>>  };
>>  
>> +/*
>> + * Architecture specific defines for kvm_guest_debug->control
>> + */
>> +
>> +#define KVM_GUESTDBG_USE_SW_BP		(1 << 16)
>> +#define KVM_GUESTDBG_USE_HW_BP		(1 << 17)
>> +
>>  struct kvm_sync_regs {
>>  };
>>  
>> -- 
>> 2.4.1
>>
diff mbox

Patch

diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index d268320..43758e7 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -100,12 +100,32 @@  struct kvm_sregs {
 struct kvm_fpu {
 };
 
+/*
+ * See v8 ARM ARM D7.3: Debug Registers
+ *
+ * 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;
 };
 
+/*
+ * Architecture specific defines for kvm_guest_debug->control
+ */
+
+#define KVM_GUESTDBG_USE_SW_BP		(1 << 16)
+#define KVM_GUESTDBG_USE_HW_BP		(1 << 17)
+
 struct kvm_sync_regs {
 };