RE: [PATCH v1 22/22] intel_iommu: modify x-scalable-mode to be string option

["Liu, Yi L" <yi.l.liu@intel.com>]

> From: Peter Xu <peterx@redhat.com>
> Sent: Wednesday, March 25, 2020 2:39 AM
> To: Liu, Yi L <yi.l.liu@intel.com>
> Subject: Re: [PATCH v1 22/22] intel_iommu: modify x-scalable-mode to be string
> option
> 
> On Sun, Mar 22, 2020 at 05:36:19AM -0700, Liu Yi L wrote:
> > Intel VT-d 3.0 introduces scalable mode, and it has a bunch of
> > capabilities related to scalable mode translation, thus there are multiple
> combinations.
> > While this vIOMMU implementation wants simplify it for user by
> > providing typical combinations. User could config it by
> > "x-scalable-mode" option. The usage is as below:
> >
> > "-device intel-iommu,x-scalable-mode=["legacy"|"modern"|"off"]"
> >
> >  - "legacy": gives support for SL page table
> >  - "modern": gives support for FL page table, pasid, virtual command
> >  - "off": no scalable mode support
> >  -  if not configured, means no scalable mode support, if not proper
> >     configured, will throw error
> >
> > Note: this patch is supposed to be merged when  the whole vSVA patch
> > series were merged.
> >
> > Cc: Kevin Tian <kevin.tian@intel.com>
> > Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > Cc: Peter Xu <peterx@redhat.com>
> > Cc: Yi Sun <yi.y.sun@linux.intel.com>
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: Richard Henderson <rth@twiddle.net>
> > Cc: Eduardo Habkost <ehabkost@redhat.com>
> > Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> > Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
> > ---
> >  hw/i386/intel_iommu.c          | 29 +++++++++++++++++++++++++++--
> >  hw/i386/intel_iommu_internal.h |  4 ++++
> > include/hw/i386/intel_iommu.h  |  2 ++
> >  3 files changed, 33 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index
> > 72cd739..ea1f5c4 100644
> > --- a/hw/i386/intel_iommu.c
> > +++ b/hw/i386/intel_iommu.c
> > @@ -4171,7 +4171,7 @@ static Property vtd_properties[] = {
> >      DEFINE_PROP_UINT8("aw-bits", IntelIOMMUState, aw_bits,
> >                        VTD_HOST_ADDRESS_WIDTH),
> >      DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode,
> FALSE),
> > -    DEFINE_PROP_BOOL("x-scalable-mode", IntelIOMMUState, scalable_mode,
> FALSE),
> > +    DEFINE_PROP_STRING("x-scalable-mode", IntelIOMMUState,
> > + scalable_mode_str),
> >      DEFINE_PROP_BOOL("dma-drain", IntelIOMMUState, dma_drain, true),
> >      DEFINE_PROP_END_OF_LIST(),
> >  };
> > @@ -4802,8 +4802,12 @@ static void vtd_init(IntelIOMMUState *s)
> >      }
> >
> >      /* TODO: read cap/ecap from host to decide which cap to be exposed. */
> > -    if (s->scalable_mode) {
> > +    if (s->scalable_mode && !s->scalable_modern) {
> >          s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_SRS | VTD_ECAP_SLTS;
> > +    } else if (s->scalable_mode && s->scalable_modern) {
> > +        s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_SRS | VTD_ECAP_PASID
> > +                   | VTD_ECAP_FLTS | VTD_ECAP_PSS | VTD_ECAP_VCS;
> > +        s->vccap |= VTD_VCCAP_PAS;
> >      }
> >
> >      vtd_reset_caches(s);
> > @@ -4935,6 +4939,27 @@ static bool vtd_decide_config(IntelIOMMUState *s,
> Error **errp)
> >          return false;
> >      }
> >
> > +    if (s->scalable_mode_str &&
> > +        (strcmp(s->scalable_mode_str, "modern") &&
> > +         strcmp(s->scalable_mode_str, "legacy"))) {
> 
> The 'off' check is missing?

Oops, yes, my bad. will add it.

Regards,
Yi Liu