Re: [Xen-devel] [PATCH 02/10] VMX: New parameter to control PML enabling

[Kai Huang <kai.huang@xxxxxxxxxxxxxxx>]

On 03/28/2015 04:42 AM, Andrew Cooper wrote:
> On 27/03/15 02:35, Kai Huang wrote:
> > A top level EPT parameter "ept=<options>" and a sub boolean "pml_enable" are
> > added to control PML. Other booleans can be further added for any other EPT
> > related features.
> >
> > Signed-off-by: Kai Huang <kai.huang@xxxxxxxxxxxxxxx>
> Please patch docs/misc/xen-command-line.markdown as well.  See the
> existing "psr" option as a similar example.
>
> Also, as indicated in patch 1, I think patches 1 and 2 need swapping in
> the series.
>
> > ---
> >   xen/arch/x86/hvm/vmx/vmcs.c | 32 ++++++++++++++++++++++++++++++++
> >   1 file changed, 32 insertions(+)
> >
> > diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
> > index 2f645fe..9b20a4b 100644
> > --- a/xen/arch/x86/hvm/vmx/vmcs.c
> > +++ b/xen/arch/x86/hvm/vmx/vmcs.c
> > @@ -50,6 +50,16 @@ boolean_param("unrestricted_guest", 
> > opt_unrestricted_guest_enabled);
> >   static bool_t __read_mostly opt_apicv_enabled = 1;
> >   boolean_param("apicv", opt_apicv_enabled);
> >   
> > +static void parse_ept_param(char *s);
> > +/*
> > + * The 'ept' parameter controls functionalities that depend on, or impact the
> > + * EPT mechanism. Optional comma separated value may contain:
> > + *
> > + *  pml                 Enable PML
> > + */
> > +custom_param("ept", parse_ept_param);
> It is common to put the custom_param() call below parse_ept_param() so
> you don't need to forward-declare the function.  The comment can happily
> live at the top of parse_ept_param().
Hi Andrew,

Looks it's better to keep parse_ept_param() below custom_param(), as 
simply moving parse_ept_param() above custom_param() results in below 
error (I also changed pml_enable to opt_pml_enabled), as it references 
opt_pml_enabled variable, which is defined below custom_param(). 
Actually for "iommu=<options>" parameter, parse_iommu_param() was also 
placed below custom_param().
What do you think?

vmcs.c: In function ‘parse_ept_param’:
vmcs.c:74:13: error: ‘opt_pml_enabled’ undeclared (first use in this 
function)
             opt_pml_enabled = val;
             ^
vmcs.c:74:13: note: each undeclared identifier is reported only once for 
each function it appears in
vmcs.c: At top level:
vmcs.c:81:29: error: ‘opt_pml_enabled’ defined but not used 
[-Werror=unused-variable]
 static bool_t __read_mostly opt_pml_enabled = 0;

Thanks,
-Kai

> > +static bool_t __read_mostly pml_enable = 0;
> > +
> >   /*
> >    * These two parameters are used to config the controls for Pause-Loop 
> > Exiting:
> >    * ple_gap:    upper bound on the amount of time between two successive
> > @@ -92,6 +102,28 @@ DEFINE_PER_CPU(bool_t, vmxon);
> >   static u32 vmcs_revision_id __read_mostly;
> >   u64 __read_mostly vmx_basic_msr;
> >   
> > +/* Copied from parse_iommu_param */
> Not a useful comment, as it is likely to diverge in the future.
>
> > +static void parse_ept_param(char *s)
> __init
>
> ~Andrew
>
> > +{
> > +    char *ss;
> > +    int val;
> > +
> > +    do {
> > +        val = !!strncmp(s, "no-", 3);
> > +        if ( !val )
> > +            s += 3;
> > +
> > +        ss = strchr(s, ',');
> > +        if ( ss )
> > +            *ss = '\0';
> > +
> > +        if ( !strcmp(s, "pml") )
> > +            pml_enable = val;
> > +
> > +        s = ss + 1;
> > +    } while ( ss );
> > +}
> > +
> >   static void __init vmx_display_features(void)
> >   {
> >       int printed = 0;
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel