Saman,
> -----Original Message-----
> From: Xen-devel <xen-devel-boun...@lists.xenproject.org> On Behalf Of Saman
> Dehghan
> Sent: Monday, September 15, 2025 9:56 AM
> To: xen-devel@lists.xenproject.org
> Cc: Saman Dehghan <samaan.dehg...@gmail.com>; Jan Beulich <jbeul...@suse.com>
> Subject: [EXTERNAL] [llvm coverage] Update LLVM profile raw format from v4 to
> v10
>
> EXT email: be mindful of links/attachments.
>
>
>
> This patch updates the LLVM profile raw format in
> `xen/common/coverage/llvm.c` from version 4 to version 10, enabling
> compatibility with LLVM versions 19 and 20.
> While the patch supports only one version:
> 1. It seems better to support one version than no version --
> the current profile version 4 is not compatible with
> LLVM version 11 or later
I'd suggest adding logic to check the LLVM version and conditionally add the
struct field(s). e.g., "__clang__", "__clang_major__" and "__clang_minor__".
[snip]
>
> Overall, this change would enhance Xen's code coverage analysis capabilities
> by leveraging the latest LLVM toolchain improvements, particularly for
> safety-critical hypervisor code.
>
> The patch modifies only `xen/common/coverage/llvm.c`, maintaining API
> compatibility while enabling modern toolchain support.
> Testing was performed with LLVM 19 and 20 to confirm functionality.
Please elaborate on your testing. You could put it under the --- so it's show
what you did but not included in the git description when merged.
E.g. what dom0 was used, command sequence, etc.
[snip]
> 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;
The above line has extra spaces at the end.
> + uint64_t padding_bytes_after_bitmap_bytes;
> uint64_t names_size;
> uint64_t counters_delta;
> + uint64_t bitmap_delta;
> uint64_t names_delta;
> + uint64_t num_vtables;
> + uint64_t vnames_size;
> uint64_t value_kind_last;
> };
>
Steps I used to build
- I checked out latest master (656b9ca03b)
- Applied this patch
- menuconfig'd to disable livepatch and enable coverage
- make dist-xen clang=y
I got the following.
CC common/coverage/llvm.o
common/coverage/llvm.c:120:10: error: field designator 'data_size' does not
refer to any field in type 'struct llvm_profile_header'
.data_size = (END_DATA - START_DATA) / sizeof(struct llvm_profile_data),
^
common/coverage/llvm.c:121:10: error: field designator 'counters_size' does not
refer to any field in type 'struct llvm_profile_header'
.counters_size = (END_COUNTERS - START_COUNTERS) / sizeof(uint64_t),
^
Best Regards,
Matt
