xen/common/coverage/llvm.c | 78 +++++++++++++++++++++++++++----------- xen/include/xen/types.h | 1 + 2 files changed, 57 insertions(+), 22 deletions(-)
This change enables compatibility for measuring code coverage
with Clang versions 14 through 20 by supporting their
respective raw profile formats.
1- Add support for LLVM raw profile versions 8, 9, and 10
2- Initialized llvm_profile_header for all versions based on llvm source code in
`compiler-rt/include/profile/InstrProfData.inc` for each version.
3- We tested this patch for all clang versions from 14 through 20 on both ARM and X86 platform
Signed-off-by: Saman Dehghan <samaan.dehghan@gmail.com>
---
xen/common/coverage/llvm.c | 78 +++++++++++++++++++++++++++-----------
xen/include/xen/types.h | 1 +
2 files changed, 57 insertions(+), 22 deletions(-)
diff --git a/xen/common/coverage/llvm.c b/xen/common/coverage/llvm.c
index 517b2aa8c2..f92f10654c 100644
--- a/xen/common/coverage/llvm.c
+++ b/xen/common/coverage/llvm.c
@@ -44,27 +44,55 @@
((uint64_t)'f' << 16) | ((uint64_t)'R' << 8) | ((uint64_t)129)
#endif
-#define LLVM_PROFILE_VERSION 4
+#if __clang_major__ >= 19
+#define LLVM_PROFILE_VERSION 10
+#define LLVM_PROFILE_NUM_KINDS 3
+#elif __clang_major__ == 18
+#define LLVM_PROFILE_VERSION 9
#define LLVM_PROFILE_NUM_KINDS 2
+#elif __clang_major__ >= 14
+#define LLVM_PROFILE_VERSION 8
+#define LLVM_PROFILE_NUM_KINDS 2
+#else
+#error "Unsupported Clang version"
+#endif
struct llvm_profile_data {
uint64_t name_ref;
uint64_t function_hash;
- void *counter;
- void *function;
- void *values;
+ intptr_t *relative_counter;
+#if __clang_major__ >= 18
+ intptr_t *relative_bitmap;
+#endif
+ intptr_t *function;
+ intptr_t *values;
uint32_t nr_counters;
uint16_t nr_value_sites[LLVM_PROFILE_NUM_KINDS];
+#if __clang_major__ >= 18
+ uint32_t numbitmap_bytes;
+#endif
};
struct llvm_profile_header {
uint64_t magic;
uint64_t version;
- uint64_t data_size;
- uint64_t counters_size;
+ uint64_t binary_ids_size;
+ uint64_t num_data;
+ uint64_t padding_bytes_before_counters;
+ uint64_t num_counters;
+ uint64_t padding_bytes_after_counters;
+ uint64_t num_bitmap_bytes;
+ uint64_t padding_bytes_after_bitmap_bytes;
uint64_t names_size;
+#if __clang_major__ >= 18
uint64_t counters_delta;
+ uint64_t bitmap_delta;
+#endif
uint64_t names_delta;
+#if __clang_major__ >= 19
+ uint64_t num_vtables;
+ uint64_t vnames_size;
+#endif
uint64_t value_kind_last;
};
@@ -76,19 +104,20 @@ struct llvm_profile_header {
*/
int __llvm_profile_runtime;
-extern const struct llvm_profile_data __start___llvm_prf_data[];
-extern const struct llvm_profile_data __stop___llvm_prf_data[];
-extern const char __start___llvm_prf_names[];
-extern const char __stop___llvm_prf_names[];
-extern uint64_t __start___llvm_prf_cnts[];
-extern uint64_t __stop___llvm_prf_cnts[];
+extern char __start___llvm_prf_data[];
+extern char __stop___llvm_prf_data[];
+extern char __start___llvm_prf_names[];
+extern char __stop___llvm_prf_names[];
+extern char __start___llvm_prf_cnts[];
+extern char __stop___llvm_prf_cnts[];
+
+#define START_DATA ((const char *)__start___llvm_prf_data)
+#define END_DATA ((const char *)__stop___llvm_prf_data)
+#define START_NAMES ((const char *)__start___llvm_prf_names)
+#define END_NAMES ((const char *)__stop___llvm_prf_names)
+#define START_COUNTERS ((char *)__start___llvm_prf_cnts)
+#define END_COUNTERS ((char *)__stop___llvm_prf_cnts)
-#define START_DATA ((const void *)__start___llvm_prf_data)
-#define END_DATA ((const void *)__stop___llvm_prf_data)
-#define START_NAMES ((const void *)__start___llvm_prf_names)
-#define END_NAMES ((const void *)__stop___llvm_prf_names)
-#define START_COUNTERS ((void *)__start___llvm_prf_cnts)
-#define END_COUNTERS ((void *)__stop___llvm_prf_cnts)
static void cf_check reset_counters(void)
{
@@ -107,10 +136,15 @@ static int cf_check dump(
struct llvm_profile_header header = {
.magic = LLVM_PROFILE_MAGIC,
.version = LLVM_PROFILE_VERSION,
- .data_size = (END_DATA - START_DATA) / sizeof(struct llvm_profile_data),
- .counters_size = (END_COUNTERS - START_COUNTERS) / sizeof(uint64_t),
- .names_size = END_NAMES - START_NAMES,
- .counters_delta = (uintptr_t)START_COUNTERS,
+ .binary_ids_size = 0,
+ .num_data = (((intptr_t)END_DATA + sizeof(struct llvm_profile_data) - 1)
+ - (intptr_t)START_DATA) / sizeof(struct llvm_profile_data),
+ .padding_bytes_before_counters = 0,
+ .num_counters = (((intptr_t)END_COUNTERS + sizeof(uint64_t) - 1)
+ - (intptr_t)START_COUNTERS) / sizeof(uint64_t),
+ .padding_bytes_after_counters = 0,
+ .names_size = (END_NAMES - START_NAMES) * sizeof(char),
+ .counters_delta = (uintptr_t)START_COUNTERS - (uintptr_t)START_DATA,
.names_delta = (uintptr_t)START_NAMES,
.value_kind_last = LLVM_PROFILE_NUM_KINDS - 1,
};
diff --git a/xen/include/xen/types.h b/xen/include/xen/types.h
index 73ddccbbd5..799bfe0b95 100644
--- a/xen/include/xen/types.h
+++ b/xen/include/xen/types.h
@@ -18,6 +18,7 @@ typedef signed long ssize_t;
typedef __PTRDIFF_TYPE__ ptrdiff_t;
typedef __UINTPTR_TYPE__ uintptr_t;
+typedef __INTPTR_TYPE__ intptr_t;
/*
* Users of this macro are expected to pass a positive value.
--
2.49.0On 01/10/2025 11:09 pm, Saman Dehghan wrote:
> This change enables compatibility for measuring code coverage
> with Clang versions 14 through 20 by supporting their
> respective raw profile formats.
>
> 1- Add support for LLVM raw profile versions 8, 9, and 10
> 2- Initialized llvm_profile_header for all versions based on llvm source code in
> `compiler-rt/include/profile/InstrProfData.inc` for each version.
> 3- We tested this patch for all clang versions from 14 through 20 on both ARM and X86 platform
>
> Signed-off-by: Saman Dehghan <samaan.dehghan@gmail.com>
CC-ing Oleksii. This should be considered for 4.21 at this point.
Coverage is an optional feature, off-by-default, but Xen does support
GCC and Clang (older Clang at least), and right now newer Clang simply
malfunctions.
I guess I should update
https://xenbits.xen.org/docs/latest/hypervisor-guide/code-coverage.html
given the new toolchain baselines.
> ---
> xen/common/coverage/llvm.c | 78 +++++++++++++++++++++++++++-----------
> xen/include/xen/types.h | 1 +
> 2 files changed, 57 insertions(+), 22 deletions(-)
>
> diff --git a/xen/common/coverage/llvm.c b/xen/common/coverage/llvm.c
> index 517b2aa8c2..f92f10654c 100644
> --- a/xen/common/coverage/llvm.c
> +++ b/xen/common/coverage/llvm.c
> @@ -44,27 +44,55 @@
> ((uint64_t)'f' << 16) | ((uint64_t)'R' << 8) | ((uint64_t)129)
> #endif
>
> -#define LLVM_PROFILE_VERSION 4
> +#if __clang_major__ >= 19
> +#define LLVM_PROFILE_VERSION 10
> +#define LLVM_PROFILE_NUM_KINDS 3
> +#elif __clang_major__ == 18
> +#define LLVM_PROFILE_VERSION 9
> #define LLVM_PROFILE_NUM_KINDS 2
> +#elif __clang_major__ >= 14
> +#define LLVM_PROFILE_VERSION 8
> +#define LLVM_PROFILE_NUM_KINDS 2
> +#else
> +#error "Unsupported Clang version"
> +#endif
Does this exclude Clang 13?
Our baseline is 11 or later. How hard would it be to support those too?
>
> struct llvm_profile_data {
> uint64_t name_ref;
> uint64_t function_hash;
> - void *counter;
> - void *function;
> - void *values;
> + intptr_t *relative_counter;
> +#if __clang_major__ >= 18
> + intptr_t *relative_bitmap;
> +#endif
> + intptr_t *function;
> + intptr_t *values;
> uint32_t nr_counters;
> uint16_t nr_value_sites[LLVM_PROFILE_NUM_KINDS];
> +#if __clang_major__ >= 18
> + uint32_t numbitmap_bytes;
> +#endif
> };
>
> struct llvm_profile_header {
> uint64_t magic;
> uint64_t version;
> - uint64_t data_size;
> - uint64_t counters_size;
> + uint64_t binary_ids_size;
> + uint64_t num_data;
> + uint64_t padding_bytes_before_counters;
> + uint64_t num_counters;
> + uint64_t padding_bytes_after_counters;
> + uint64_t num_bitmap_bytes;
> + uint64_t padding_bytes_after_bitmap_bytes;
> uint64_t names_size;
> +#if __clang_major__ >= 18
> uint64_t counters_delta;
> + uint64_t bitmap_delta;
> +#endif
> uint64_t names_delta;
> +#if __clang_major__ >= 19
> + uint64_t num_vtables;
> + uint64_t vnames_size;
> +#endif
> uint64_t value_kind_last;
> };
>
> @@ -76,19 +104,20 @@ struct llvm_profile_header {
> */
> int __llvm_profile_runtime;
>
> -extern const struct llvm_profile_data __start___llvm_prf_data[];
> -extern const struct llvm_profile_data __stop___llvm_prf_data[];
> -extern const char __start___llvm_prf_names[];
> -extern const char __stop___llvm_prf_names[];
> -extern uint64_t __start___llvm_prf_cnts[];
> -extern uint64_t __stop___llvm_prf_cnts[];
> +extern char __start___llvm_prf_data[];
> +extern char __stop___llvm_prf_data[];
> +extern char __start___llvm_prf_names[];
> +extern char __stop___llvm_prf_names[];
> +extern char __start___llvm_prf_cnts[];
> +extern char __stop___llvm_prf_cnts[];
> +
> +#define START_DATA ((const char *)__start___llvm_prf_data)
> +#define END_DATA ((const char *)__stop___llvm_prf_data)
> +#define START_NAMES ((const char *)__start___llvm_prf_names)
> +#define END_NAMES ((const char *)__stop___llvm_prf_names)
> +#define START_COUNTERS ((char *)__start___llvm_prf_cnts)
> +#define END_COUNTERS ((char *)__stop___llvm_prf_cnts)
>
> -#define START_DATA ((const void *)__start___llvm_prf_data)
> -#define END_DATA ((const void *)__stop___llvm_prf_data)
> -#define START_NAMES ((const void *)__start___llvm_prf_names)
> -#define END_NAMES ((const void *)__stop___llvm_prf_names)
> -#define START_COUNTERS ((void *)__start___llvm_prf_cnts)
> -#define END_COUNTERS ((void *)__stop___llvm_prf_cnts)
Why change these from char to void ?
>
> static void cf_check reset_counters(void)
> {
> @@ -107,10 +136,15 @@ static int cf_check dump(
> struct llvm_profile_header header = {
> .magic = LLVM_PROFILE_MAGIC,
> .version = LLVM_PROFILE_VERSION,
> - .data_size = (END_DATA - START_DATA) / sizeof(struct llvm_profile_data),
> - .counters_size = (END_COUNTERS - START_COUNTERS) / sizeof(uint64_t),
> - .names_size = END_NAMES - START_NAMES,
> - .counters_delta = (uintptr_t)START_COUNTERS,
> + .binary_ids_size = 0,
> + .num_data = (((intptr_t)END_DATA + sizeof(struct llvm_profile_data) - 1)
> + - (intptr_t)START_DATA) / sizeof(struct llvm_profile_data),
I can see why we might want to round-down END, but this doesn't need
casting to intptr_t irrespective of char vs void.
> + .padding_bytes_before_counters = 0,
> + .num_counters = (((intptr_t)END_COUNTERS + sizeof(uint64_t) - 1)
> + - (intptr_t)START_COUNTERS) / sizeof(uint64_t),
> + .padding_bytes_after_counters = 0,
> + .names_size = (END_NAMES - START_NAMES) * sizeof(char),
sizeof(char) is by definition 1.
> + .counters_delta = (uintptr_t)START_COUNTERS - (uintptr_t)START_DATA,
> .names_delta = (uintptr_t)START_NAMES,
> .value_kind_last = LLVM_PROFILE_NUM_KINDS - 1,
> };
> diff --git a/xen/include/xen/types.h b/xen/include/xen/types.h
> index 73ddccbbd5..799bfe0b95 100644
> --- a/xen/include/xen/types.h
> +++ b/xen/include/xen/types.h
> @@ -18,6 +18,7 @@ typedef signed long ssize_t;
>
> typedef __PTRDIFF_TYPE__ ptrdiff_t;
> typedef __UINTPTR_TYPE__ uintptr_t;
> +typedef __INTPTR_TYPE__ intptr_t;
>
> /*
> * Users of this macro are expected to pass a positive value.
On 10/2/25 11:53 AM, Andrew Cooper wrote:
> On 01/10/2025 11:09 pm, Saman Dehghan wrote:
>> This change enables compatibility for measuring code coverage
>> with Clang versions 14 through 20 by supporting their
>> respective raw profile formats.
>>
>> 1- Add support for LLVM raw profile versions 8, 9, and 10
>> 2- Initialized llvm_profile_header for all versions based on llvm source code in
>> `compiler-rt/include/profile/InstrProfData.inc` for each version.
>> 3- We tested this patch for all clang versions from 14 through 20 on both ARM and X86 platform
>>
>> Signed-off-by: Saman Dehghan<samaan.dehghan@gmail.com>
> CC-ing Oleksii. This should be considered for 4.21 at this point.
>
> Coverage is an optional feature, off-by-default, but Xen does support
> GCC and Clang (older Clang at least), and right now newer Clang simply
> malfunctions.
In this case, I agree that it should be considered for 4.21:
Release-Acked-By: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Thanks.
~ Oleksii
>
> I guess I should update
> https://xenbits.xen.org/docs/latest/hypervisor-guide/code-coverage.html
> given the new toolchain baselines.
>
>> ---
>> xen/common/coverage/llvm.c | 78 +++++++++++++++++++++++++++-----------
>> xen/include/xen/types.h | 1 +
>> 2 files changed, 57 insertions(+), 22 deletions(-)
>>
>> diff --git a/xen/common/coverage/llvm.c b/xen/common/coverage/llvm.c
>> index 517b2aa8c2..f92f10654c 100644
>> --- a/xen/common/coverage/llvm.c
>> +++ b/xen/common/coverage/llvm.c
>> @@ -44,27 +44,55 @@
>> ((uint64_t)'f' << 16) | ((uint64_t)'R' << 8) | ((uint64_t)129)
>> #endif
>>
>> -#define LLVM_PROFILE_VERSION 4
>> +#if __clang_major__ >= 19
>> +#define LLVM_PROFILE_VERSION 10
>> +#define LLVM_PROFILE_NUM_KINDS 3
>> +#elif __clang_major__ == 18
>> +#define LLVM_PROFILE_VERSION 9
>> #define LLVM_PROFILE_NUM_KINDS 2
>> +#elif __clang_major__ >= 14
>> +#define LLVM_PROFILE_VERSION 8
>> +#define LLVM_PROFILE_NUM_KINDS 2
>> +#else
>> +#error "Unsupported Clang version"
>> +#endif
> Does this exclude Clang 13?
>
> Our baseline is 11 or later. How hard would it be to support those too?
>
>>
>> struct llvm_profile_data {
>> uint64_t name_ref;
>> uint64_t function_hash;
>> - void *counter;
>> - void *function;
>> - void *values;
>> + intptr_t *relative_counter;
>> +#if __clang_major__ >= 18
>> + intptr_t *relative_bitmap;
>> +#endif
>> + intptr_t *function;
>> + intptr_t *values;
>> uint32_t nr_counters;
>> uint16_t nr_value_sites[LLVM_PROFILE_NUM_KINDS];
>> +#if __clang_major__ >= 18
>> + uint32_t numbitmap_bytes;
>> +#endif
>> };
>>
>> struct llvm_profile_header {
>> uint64_t magic;
>> uint64_t version;
>> - uint64_t data_size;
>> - uint64_t counters_size;
>> + uint64_t binary_ids_size;
>> + uint64_t num_data;
>> + uint64_t padding_bytes_before_counters;
>> + uint64_t num_counters;
>> + uint64_t padding_bytes_after_counters;
>> + uint64_t num_bitmap_bytes;
>> + uint64_t padding_bytes_after_bitmap_bytes;
>> uint64_t names_size;
>> +#if __clang_major__ >= 18
>> uint64_t counters_delta;
>> + uint64_t bitmap_delta;
>> +#endif
>> uint64_t names_delta;
>> +#if __clang_major__ >= 19
>> + uint64_t num_vtables;
>> + uint64_t vnames_size;
>> +#endif
>> uint64_t value_kind_last;
>> };
>>
>> @@ -76,19 +104,20 @@ struct llvm_profile_header {
>> */
>> int __llvm_profile_runtime;
>>
>> -extern const struct llvm_profile_data __start___llvm_prf_data[];
>> -extern const struct llvm_profile_data __stop___llvm_prf_data[];
>> -extern const char __start___llvm_prf_names[];
>> -extern const char __stop___llvm_prf_names[];
>> -extern uint64_t __start___llvm_prf_cnts[];
>> -extern uint64_t __stop___llvm_prf_cnts[];
>> +extern char __start___llvm_prf_data[];
>> +extern char __stop___llvm_prf_data[];
>> +extern char __start___llvm_prf_names[];
>> +extern char __stop___llvm_prf_names[];
>> +extern char __start___llvm_prf_cnts[];
>> +extern char __stop___llvm_prf_cnts[];
>> +
>> +#define START_DATA ((const char *)__start___llvm_prf_data)
>> +#define END_DATA ((const char *)__stop___llvm_prf_data)
>> +#define START_NAMES ((const char *)__start___llvm_prf_names)
>> +#define END_NAMES ((const char *)__stop___llvm_prf_names)
>> +#define START_COUNTERS ((char *)__start___llvm_prf_cnts)
>> +#define END_COUNTERS ((char *)__stop___llvm_prf_cnts)
>>
>> -#define START_DATA ((const void *)__start___llvm_prf_data)
>> -#define END_DATA ((const void *)__stop___llvm_prf_data)
>> -#define START_NAMES ((const void *)__start___llvm_prf_names)
>> -#define END_NAMES ((const void *)__stop___llvm_prf_names)
>> -#define START_COUNTERS ((void *)__start___llvm_prf_cnts)
>> -#define END_COUNTERS ((void *)__stop___llvm_prf_cnts)
> Why change these from char to void ?
>
>>
>> static void cf_check reset_counters(void)
>> {
>> @@ -107,10 +136,15 @@ static int cf_check dump(
>> struct llvm_profile_header header = {
>> .magic = LLVM_PROFILE_MAGIC,
>> .version = LLVM_PROFILE_VERSION,
>> - .data_size = (END_DATA - START_DATA) / sizeof(struct llvm_profile_data),
>> - .counters_size = (END_COUNTERS - START_COUNTERS) / sizeof(uint64_t),
>> - .names_size = END_NAMES - START_NAMES,
>> - .counters_delta = (uintptr_t)START_COUNTERS,
>> + .binary_ids_size = 0,
>> + .num_data = (((intptr_t)END_DATA + sizeof(struct llvm_profile_data) - 1)
>> + - (intptr_t)START_DATA) / sizeof(struct llvm_profile_data),
> I can see why we might want to round-down END, but this doesn't need
> casting to intptr_t irrespective of char vs void.
>
>> + .padding_bytes_before_counters = 0,
>> + .num_counters = (((intptr_t)END_COUNTERS + sizeof(uint64_t) - 1)
>> + - (intptr_t)START_COUNTERS) / sizeof(uint64_t),
>> + .padding_bytes_after_counters = 0,
>> + .names_size = (END_NAMES - START_NAMES) * sizeof(char),
> sizeof(char) is by definition 1.
>
>> + .counters_delta = (uintptr_t)START_COUNTERS - (uintptr_t)START_DATA,
>> .names_delta = (uintptr_t)START_NAMES,
>> .value_kind_last = LLVM_PROFILE_NUM_KINDS - 1,
>> };
>> diff --git a/xen/include/xen/types.h b/xen/include/xen/types.h
>> index 73ddccbbd5..799bfe0b95 100644
>> --- a/xen/include/xen/types.h
>> +++ b/xen/include/xen/types.h
>> @@ -18,6 +18,7 @@ typedef signed long ssize_t;
>>
>> typedef __PTRDIFF_TYPE__ ptrdiff_t;
>> typedef __UINTPTR_TYPE__ uintptr_t;
>> +typedef __INTPTR_TYPE__ intptr_t;
>>
>> /*
>> * Users of this macro are expected to pass a positive value.
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