Re: [PATCH v2] KVM: selftests: Compile code with warnings enabled

Paolo Bonzini
2019-05-20T10:00:50Z

On 17/05/19 12:07, Thomas Huth wrote:
>
> lib/ucall.c: In function ‘get_ucall’:
> lib/ucall.c:145:3: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> gva = *(vm_vaddr_t *)run->mmio.data;
>
> x86_64/vmx_set_nested_state_test.c: In function
> ‘set_revision_id_for_vmcs12’:
> x86_64/vmx_set_nested_state_test.c:78:2: warning: dereferencing
> type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
> *(u32 *)(state->data) = vmcs12_revision;
>
> ... how do we want to handle such spots in the kvm selftest code?
> Compile with -fno-strict-aliasing? Or fix it with type-punning through
> unions?

I would use memcpy. I'll send a patch shortly.

Paolo