On Wed Sep 24, 2025 at 12:14 PM CEST, Grygorii Strashko wrote: > From: Grygorii Strashko <[email protected]> > > Since commit b99227347230 ("x86: Fix AMD_SVM and INTEL_VMX dependency") the > HVM Intel VT-x support can be disabled, but it still keeps VMX > code partially built-in. Particularly in HVM code there are two places: > > 1) hvm/dom0_build.c > dom0_construct_pvh()->pvh_populate_p2m() > ... > if ( cpu_has_vmx && paging_mode_hap(d) && !vmx_unrestricted_guest(v) ) > { > ... > [unreachable for !cpu_has_vmx case] > rc = pvh_setup_vmx_realmode_helpers(d); > > pvh_setup_vmx_realmode_helpers() allocates memory and configures > HVM_PARAM_VM86_TSS_SIZED > HVM_PARAM_IDENT_PT > > 2) hvm/hvm.c > hvm_set_param() > ... > case HVM_PARAM_IDENT_PT: > > if ( !paging_mode_hap(d) || !cpu_has_vmx ) > { > d->arch.hvm.params[index] = value; > break; > } > [unreachable for !cpu_has_vmx case] > ...
nit: These (1) and (2) are rather large for a commit message. I wouldn't mind if they went away and the rest of the commit message was adjusted to make it a bit leaner. Either way, with or without this change... > > Hence HVM_PARAM_IDENT_PT/HVM_PARAM_VM86_TSS_SIZED are used only by VMX code > above code become unreachable in !cpu_has_vmx case and can be optimazed > when !CONFIG_INTEL_VMX. > > Replace "cpu_has_vmx" with using_vmx() to account !CONFIG_INTEL_VMX and allow > compiler DCE to optimize code. > > Signed-off-by: Grygorii Strashko <[email protected]> ... Reviewed-by: Alejandro Vallejo <[email protected]> Cheers, Alejandro
