Re: [PATCH 13/18 V2]: PVH xen: introduce p2m_map_foreign

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

On Fri, Mar 15, 2013 at 05:51:09PM -0700, Mukesh Rathor wrote:
>  In this patch, I introduce  a new type p2m_map_foreign for pages that a
>  dom0 maps from foreign domains its creating. Also, add
>  set_foreign_p2m_entry() to map p2m_map_foreign type pages. Other misc changes
>  related to p2m.
> 
> Changes in V2:
>    - Make guest_physmap_add_entry() same for PVH in terms of overwriting old
>      entry.
>    - In set_foreign_p2m_entry() do locked get_gfn and not unlocked.
>    - Replace ASSERT with return -EINVAL in do_physdev_op.
>    - Remove unnecessary check for PVH in do_physdev_op().
> 

You should really CC Tim on this patch. Doing it for you.
> Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
> ---
>  xen/arch/x86/domctl.c     |   19 +++++++++++++------
>  xen/arch/x86/mm/p2m-ept.c |    3 ++-
>  xen/arch/x86/mm/p2m-pt.c  |    3 ++-
>  xen/arch/x86/mm/p2m.c     |   30 +++++++++++++++++++++++++++++-
>  xen/arch/x86/physdev.c    |    8 ++++++++
>  xen/include/asm-x86/p2m.h |    4 ++++
>  6 files changed, 58 insertions(+), 9 deletions(-)
> 
> diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
> index ecc8240..da49d6d 100644
> --- a/xen/arch/x86/domctl.c
> +++ b/xen/arch/x86/domctl.c
> @@ -64,9 +64,10 @@ long domctl_memory_mapping(struct domain *d, unsigned long gfn,
>  
>      if ( add_map )
>      {
> -        printk(XENLOG_G_INFO
> -               "memory_map:add: dom%d gfn=%lx mfn=%lx nr=%lx\n",
> -               d->domain_id, gfn, mfn, nr_mfns);
> +        if ( !is_pvh_domain(d) )     /* PVH maps lots and lots */
> +            printk(XENLOG_G_INFO
> +                   "memory_map:add: dom%d gfn=%lx mfn=%lx nr=%lx\n",
> +                   d->domain_id, gfn, mfn, nr_mfns);
>  
>          ret = iomem_permit_access(d, mfn, mfn + nr_mfns - 1);
>          if ( !ret && paging_mode_translate(d) )
> @@ -89,9 +90,10 @@ long domctl_memory_mapping(struct domain *d, unsigned long gfn,
>              }
>          }
>      } else {
> -        printk(XENLOG_G_INFO
> -               "memory_map:remove: dom%d gfn=%lx mfn=%lx nr=%lx\n",
> -               d->domain_id, gfn, mfn, nr_mfns);
> +        if ( !is_pvh_domain(d) )     /* PVH unmaps lots and lots */
> +            printk(XENLOG_G_INFO
> +                   "memory_map:remove: dom%d gfn=%lx mfn=%lx nr=%lx\n",
> +                   d->domain_id, gfn, mfn, nr_mfns);
>  
>          if ( paging_mode_translate(d) )
>              for ( i = 0; i < nr_mfns; i++ )
> @@ -1307,6 +1309,11 @@ void arch_get_info_guest(struct vcpu *v, vcpu_guest_context_u c)
>              c.nat->gs_base_kernel = hvm_get_shadow_gs_base(v);
>          }
>      }
> +    else if ( is_pvh_vcpu(v) )
> +    {
> +        /* fixme: punt it to phase II */
> +        printk("PVH: fixme: arch_get_info_guest()\n");
> +    }
>      else
>      {
>          c(ldt_base = v->arch.pv_vcpu.ldt_base);
> diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
> index a2d1591..38ea9ec 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;
> @@ -430,7 +431,7 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn,
>      }
>  
>      /* Track the highest gfn for which we have ever had a valid mapping */
> -    if ( p2mt != p2m_invalid &&
> +    if ( p2mt != p2m_invalid && p2mt != p2m_mmio_dm &&
>           (gfn + (1UL << order) - 1 > p2m->max_mapped_pfn) )
>          p2m->max_mapped_pfn = gfn + (1UL << order) - 1;
>  
> diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
> index 302b621..3f46418 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)) )
> @@ -429,7 +430,7 @@ p2m_set_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn,
>      }
>  
>      /* Track the highest gfn for which we have ever had a valid mapping */
> -    if ( p2mt != p2m_invalid
> +    if ( p2mt != p2m_invalid && p2mt != p2m_mmio_dm
>           && (gfn + (1UL << page_order) - 1 > p2m->max_mapped_pfn) )
>          p2m->max_mapped_pfn = gfn + (1UL << page_order) - 1;
>  
> diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
> index 4837de3..6888cf1 100644
> --- a/xen/arch/x86/mm/p2m.c
> +++ b/xen/arch/x86/mm/p2m.c
> @@ -523,7 +523,7 @@ 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) );
>          }
> @@ -754,7 +754,35 @@ void p2m_change_type_range(struct domain *d,
>      p2m_unlock(p2m);
>  }
>  
> +/* Returns: True for success. 0 for failure */

You mean 1 for success? If so, why not just use a bool?

> +int set_foreign_p2m_entry(struct domain *dp, unsigned long gfn, mfn_t mfn)
> +{
> +    int rc = 0;
> +    p2m_type_t ot;
> +    mfn_t omfn;
> +    struct p2m_domain *p2m = p2m_get_hostp2m(dp);
> +
> +    if ( !paging_mode_translate(dp) )
> +        return 0;
> +
> +    omfn = get_gfn_query(dp, gfn, &ot);
> +    if (mfn_valid(omfn)) {
> +        gdprintk(XENLOG_ERR, "Already mapped mfn %lx at gfn:%lx\n", 
> +                 mfn_x(omfn), gfn);
> +        set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
> +    }
> +    put_gfn(dp, gfn);
>  
> +    P2M_DEBUG("set foreign %lx %lx\n", gfn, mfn_x(mfn));
> +    p2m_lock(p2m);
> +    rc = set_p2m_entry(p2m, gfn, mfn, 0, p2m_map_foreign, p2m->default_access);
> +    p2m_unlock(p2m);
> +    if ( rc == 0 )
> +        gdprintk(XENLOG_ERR,
> +            "set_foreign_p2m_entry: set_p2m_entry failed! gfn:%lx mfn=%08lx\n",
> +            gfn, mfn_x(get_gfn_query(dp, gfn, &ot)));
> +    return rc;
> +}
>  
>  int
>  set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
> diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
> index 876ac9d..ca66c1c 100644
> --- a/xen/arch/x86/physdev.c
> +++ b/xen/arch/x86/physdev.c
> @@ -475,6 +475,12 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>  
>      case PHYSDEVOP_set_iopl: {
>          struct physdev_set_iopl set_iopl;
> +
> +        if ( is_pvh_vcpu(current) ) {
> +            ret = -EINVAL;

That looks like it belongs to a different patch - one that filters
which of the hypercalls should NOT be called when doing PVH.

And perhaps -ENOSYS?

> +            break;
> +        }
> +
>          ret = -EFAULT;
>          if ( copy_from_guest(&set_iopl, arg, 1) != 0 )
>              break;
> @@ -488,6 +494,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>  
>      case PHYSDEVOP_set_iobitmap: {
>          struct physdev_set_iobitmap set_iobitmap;
> +
> +        ASSERT( !is_pvh_vcpu(current) );

Ouch! Why not the same treatment as previously? return -ENOSYS.

>          ret = -EFAULT;
>          if ( copy_from_guest(&set_iobitmap, arg, 1) != 0 )
>              break;
> diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
> index 43583b2..b76dc33 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 (for pvh dom0) */
> +int set_foreign_p2m_entry(struct domain *domp, unsigned long gfn, mfn_t mfn);
>  
>  /* 
>   * Populate-on-demand
> -- 
> 1.7.2.3
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
>