Re: [XEN][PATCH] x86/hvm: move hvm_shadow_handle_cd() under CONFIG_INTEL_VMX ifdef

[Grygorii Strashko <grygorii_strashko@xxxxxxxx>]

On 25.10.25 21:10, Teddy Astie wrote:
> Le 23/10/2025 à 17:22, Grygorii Strashko a écrit :
> > From: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
> >
> > Functions:
> >    hvm_shadow_handle_cd()
> >    hvm_set_uc_mode()
> >    domain_exit_uc_mode()
> > are used only by Intel VMX code, so move them under CONFIG_INTEL_VMX ifdef.
> If they are actually Intel VMX specific, they should rather be moved to
> VMX code (and named appropriately) rather than if-defed in shared hvm
> code. If AMD code happens to need these functions in the future, it
> would make things break pretty confusingly (as headers are not updated
> consistently).
I agree and like it even better. Can try if there is no objections?

There is hvm_prepare_vm86_tss() also which is also used by VMX code only.

> > Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
> > ---
> >    xen/arch/x86/hvm/hvm.c | 50 ++++++++++++++++++++++--------------------
> >    1 file changed, 26 insertions(+), 24 deletions(-)
> >
> > diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
> > index f1035fc9f645..3a30404d9940 100644
> > --- a/xen/arch/x86/hvm/hvm.c
> > +++ b/xen/arch/x86/hvm/hvm.c
> > @@ -2168,30 +2168,6 @@ int hvm_set_efer(uint64_t value)
> >        return X86EMUL_OKAY;
> >    }
> >    
> > -/* Exit UC mode only if all VCPUs agree on MTRR/PAT and are not in no_fill. */
> > -static bool domain_exit_uc_mode(struct vcpu *v)
> > -{
> > -    struct domain *d = v->domain;
> > -    struct vcpu *vs;
> > -
> > -    for_each_vcpu ( d, vs )
> > -    {
> > -        if ( (vs == v) || !vs->is_initialised )
> > -            continue;
> > -        if ( (vs->arch.hvm.cache_mode == NO_FILL_CACHE_MODE) ||
> > -             mtrr_pat_not_equal(vs, v) )
> > -            return 0;
> > -    }
> > -
> > -    return 1;
> > -}
> > -
> > -static void hvm_set_uc_mode(struct vcpu *v, bool is_in_uc_mode)
> > -{
> > -    v->domain->arch.hvm.is_in_uc_mode = is_in_uc_mode;
> > -    shadow_blow_tables_per_domain(v->domain);
> > -}
> > -
> >    int hvm_mov_to_cr(unsigned int cr, unsigned int gpr)
> >    {
> >        struct vcpu *curr = current;
> > @@ -2273,6 +2249,31 @@ int hvm_mov_from_cr(unsigned int cr, unsigned int gpr)
> >        return X86EMUL_UNHANDLEABLE;
> >    }
> >    
> > +#ifdef CONFIG_INTEL_VMX
> > +/* Exit UC mode only if all VCPUs agree on MTRR/PAT and are not in no_fill. */
> > +static bool domain_exit_uc_mode(struct vcpu *v)
> > +{
> > +    struct domain *d = v->domain;
> > +    struct vcpu *vs;
> > +
> > +    for_each_vcpu ( d, vs )
> > +    {
> > +        if ( (vs == v) || !vs->is_initialised )
> > +            continue;
> > +        if ( (vs->arch.hvm.cache_mode == NO_FILL_CACHE_MODE) ||
> > +             mtrr_pat_not_equal(vs, v) )
> > +            return 0;
> > +    }
> > +
> > +    return 1;
> > +}
> > +
> > +static void hvm_set_uc_mode(struct vcpu *v, bool is_in_uc_mode)
> > +{
> > +    v->domain->arch.hvm.is_in_uc_mode = is_in_uc_mode;
> > +    shadow_blow_tables_per_domain(v->domain);
> > +}
> > +
> >    void hvm_shadow_handle_cd(struct vcpu *v, unsigned long value)
> >    {
> >        if ( value & X86_CR0_CD )
> > @@ -2306,6 +2307,7 @@ void hvm_shadow_handle_cd(struct vcpu *v, unsigned long 
> > value)
> >            spin_unlock(&v->domain->arch.hvm.uc_lock);
> >        }
> >    }
> > +#endif
> >    
> >    static void hvm_update_cr(struct vcpu *v, unsigned int cr, unsigned long value)
> >    {
--
Best regards,
-grygorii