Re: [V1 PATCH 08/11] PVH dom0: Introduce p2m_map_foreign

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Nov 08, 2013 at 05:23:33PM -0800, Mukesh Rathor wrote:
> In this patch, a new type p2m_map_foreign is introduced for pages
> that toolstack on PVH dom0 maps from foreign domains that its creating.

Is it only for creating? I thought it was used during run-time as well?
Say you need to use xenctx or anything else to map a foreign domain?

> 
> Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
> ---
>  xen/arch/x86/mm/p2m-ept.c |    1 +
>  xen/arch/x86/mm/p2m-pt.c  |    1 +
>  xen/arch/x86/mm/p2m.c     |   28 ++++++++++++++++++++--------
>  xen/include/asm-x86/p2m.h |    4 ++++
>  4 files changed, 26 insertions(+), 8 deletions(-)
> 
> diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
> index 595c6e7..67c200c 100644
> --- a/xen/arch/x86/mm/p2m-ept.c
> +++ b/xen/arch/x86/mm/p2m-ept.c
> @@ -75,6 +75,7 @@ static void ept_p2m_type_to_flags(ept_entry_t *entry, p2m_type_t type, p2m_acces
>              entry->w = 0;
>              break;
>          case p2m_grant_map_rw:
> +        case p2m_map_foreign:
>              entry->r = entry->w = 1;
>              entry->x = 0;
>              break;
> diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
> index a1d5650..09b60ce 100644
> --- a/xen/arch/x86/mm/p2m-pt.c
> +++ b/xen/arch/x86/mm/p2m-pt.c
> @@ -89,6 +89,7 @@ static unsigned long p2m_type_to_flags(p2m_type_t t, mfn_t mfn)
>      case p2m_ram_rw:
>          return flags | P2M_BASE_FLAGS | _PAGE_RW;
>      case p2m_grant_map_rw:
> +    case p2m_map_foreign:
>          return flags | P2M_BASE_FLAGS | _PAGE_RW | _PAGE_NX_BIT;
>      case p2m_mmio_direct:
>          if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn_x(mfn)) )
> diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
> index 8f380ed..b9755e4 100644
> --- a/xen/arch/x86/mm/p2m.c
> +++ b/xen/arch/x86/mm/p2m.c
> @@ -525,7 +525,7 @@ p2m_remove_page(struct p2m_domain *p2m, unsigned long gfn, unsigned long mfn,
>          for ( i = 0; i < (1UL << page_order); i++ )
>          {
>              mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, 0, NULL);
> -            if ( !p2m_is_grant(t) && !p2m_is_shared(t) )
> +            if ( !p2m_is_grant(t) && !p2m_is_shared(t) && !p2m_is_foreign(t) )
>                  set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY);
>              ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) );
>          }
> @@ -756,10 +756,9 @@ void p2m_change_type_range(struct domain *d,
>      p2m_unlock(p2m);
>  }
>  
> -
> -
> -int
> -set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
> +static int
> +set_typed_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
> +                    p2m_type_t gfn_p2mt)
>  {
>      int rc = 0;
>      p2m_access_t a;
> @@ -784,16 +783,29 @@ set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
>          set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
>      }
>  
> -    P2M_DEBUG("set mmio %lx %lx\n", gfn, mfn_x(mfn));
> -    rc = set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_mmio_direct, p2m->default_access);
> +    P2M_DEBUG("set %d %lx %lx\n", gfn_p2mt, gfn, mfn_x(mfn));
> +    rc = set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, gfn_p2mt,
> +                       p2m->default_access);
>      gfn_unlock(p2m, gfn, 0);
>      if ( 0 == rc )
>          gdprintk(XENLOG_ERR,
> -            "set_mmio_p2m_entry: set_p2m_entry failed! mfn=%08lx\n",
> +            "%s: set_p2m_entry failed! mfn=%08lx\n", __func__,
>              mfn_x(get_gfn_query_unlocked(p2m->domain, gfn, &ot)));
>      return rc;
>  }
>  
> +/* Returns: True for success. 0 for failure. */

Um, 'true' and '0' ? Shouldn't it say 'True for success, false for failure?'

Or '1 for success, 0 for failure?'


> +int set_foreign_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
> +{
> +    return set_typed_p2m_entry(d, gfn, mfn, p2m_map_foreign);
> +}
> +
> +int
> +set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
> +{
> +    return set_typed_p2m_entry(d, gfn, mfn, p2m_mmio_direct);
> +}
> +
>  int
>  clear_mmio_p2m_entry(struct domain *d, unsigned long gfn)
>  {
> diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
> index 43583b2..6fc71a1 100644
> --- a/xen/include/asm-x86/p2m.h
> +++ b/xen/include/asm-x86/p2m.h
> @@ -70,6 +70,7 @@ typedef enum {
>      p2m_ram_paging_in = 11,       /* Memory that is being paged in */
>      p2m_ram_shared = 12,          /* Shared or sharable memory */
>      p2m_ram_broken = 13,          /* Broken page, access cause domain crash */
> +    p2m_map_foreign  = 14,        /* ram pages from foreign domain */
>  } p2m_type_t;
>  
>  /*
> @@ -180,6 +181,7 @@ typedef unsigned int p2m_query_t;
>  #define p2m_is_sharable(_t) (p2m_to_mask(_t) & P2M_SHARABLE_TYPES)
>  #define p2m_is_shared(_t)   (p2m_to_mask(_t) & P2M_SHARED_TYPES)
>  #define p2m_is_broken(_t)   (p2m_to_mask(_t) & P2M_BROKEN_TYPES)
> +#define p2m_is_foreign(_t)  (p2m_to_mask(_t) & p2m_to_mask(p2m_map_foreign))
>  
>  /* Per-p2m-table state */
>  struct p2m_domain {
> @@ -510,6 +512,8 @@ p2m_type_t p2m_change_type(struct domain *d, unsigned long gfn,
>  int set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn);
>  int clear_mmio_p2m_entry(struct domain *d, unsigned long gfn);
>  
> +/* Set foreign mfn in the current guest's p2m table. */
> +int set_foreign_p2m_entry(struct domain *domp, unsigned long gfn, mfn_t mfn);
>  
>  /* 
>   * Populate-on-demand
> -- 
> 1.7.2.3
> 
> 
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