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Re: [Xen-devel] [PATCH] Don't track all memory when enabling log dirty to track vram



create ^
title it HAP dirty vram tracking breaks pass-through
thanks

On Mon, Feb 10, 2014 at 6:14 AM, Yang Zhang <yang.z.zhang@xxxxxxxxx> wrote:
> From: Yang Zhang <yang.z.zhang@xxxxxxxxx>
>
> When enabling log dirty mode, it sets all guest's memory to readonly.
> And in HAP enabled domain, it modifies all EPT entries to clear write bit
> to make sure it is readonly. This will cause problem if VT-d shares page
> table with EPT: the device may issue a DMA write request, then VT-d engine
> tells it the target memory is readonly and result in VT-d fault.
>
> Currnetly, there are two places will enable log dirty mode: migration and vram
> tracking. Migration with device assigned is not allowed, so it is ok. For 
> vram,
> it doesn't need to set all memory to readonly. Only track the vram range is 
> enough.
>
> Signed-off-by: Yang Zhang <yang.z.zhang@xxxxxxxxx>
> ---
>  xen/arch/x86/mm/hap/hap.c       |   20 ++++++++++++++------
>  xen/arch/x86/mm/paging.c        |    9 +++++----
>  xen/arch/x86/mm/shadow/common.c |    2 +-
>  xen/include/asm-x86/domain.h    |    2 +-
>  xen/include/asm-x86/paging.h    |    5 +++--
>  xen/include/asm-x86/shadow.h    |    2 +-
>  6 files changed, 25 insertions(+), 15 deletions(-)
>
> diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
> index d3f64bd..5f75636 100644
> --- a/xen/arch/x86/mm/hap/hap.c
> +++ b/xen/arch/x86/mm/hap/hap.c
> @@ -82,7 +82,7 @@ int hap_track_dirty_vram(struct domain *d,
>          if ( !paging_mode_log_dirty(d) )
>          {
>              hap_logdirty_init(d);
> -            rc = paging_log_dirty_enable(d);
> +            rc = paging_log_dirty_enable(d, 0);
>              if ( rc )
>                  goto out;
>          }
> @@ -167,17 +167,25 @@ out:
>  /*            HAP LOG DIRTY SUPPORT             */
>  /************************************************/
>
> -/* hap code to call when log_dirty is enable. return 0 if no problem found. 
> */
> -static int hap_enable_log_dirty(struct domain *d)
> +/*
> + * hap code to call when log_dirty is enable. return 0 if no problem found.
> + *
> + * NB: Domain that having device assigned should not set log_global. Because
> + * there is no way to track the memory updating from device.
> + */
> +static int hap_enable_log_dirty(struct domain *d, bool_t log_global)
>  {
>      /* turn on PG_log_dirty bit in paging mode */
>      paging_lock(d);
>      d->arch.paging.mode |= PG_log_dirty;
>      paging_unlock(d);
>
> -    /* set l1e entries of P2M table to be read-only. */
> -    p2m_change_entry_type_global(d, p2m_ram_rw, p2m_ram_logdirty);
> -    flush_tlb_mask(d->domain_dirty_cpumask);
> +    if ( log_global )
> +    {
> +        /* set l1e entries of P2M table to be read-only. */
> +        p2m_change_entry_type_global(d, p2m_ram_rw, p2m_ram_logdirty);
> +        flush_tlb_mask(d->domain_dirty_cpumask);
> +    }
>      return 0;
>  }
>
> diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c
> index 21344e5..ab5eacb 100644
> --- a/xen/arch/x86/mm/paging.c
> +++ b/xen/arch/x86/mm/paging.c
> @@ -164,7 +164,7 @@ void paging_free_log_dirty_bitmap(struct domain *d)
>      paging_unlock(d);
>  }
>
> -int paging_log_dirty_enable(struct domain *d)
> +int paging_log_dirty_enable(struct domain *d, bool_t log_global)
>  {
>      int ret;
>
> @@ -172,7 +172,7 @@ int paging_log_dirty_enable(struct domain *d)
>          return -EINVAL;
>
>      domain_pause(d);
> -    ret = d->arch.paging.log_dirty.enable_log_dirty(d);
> +    ret = d->arch.paging.log_dirty.enable_log_dirty(d, log_global);
>      domain_unpause(d);
>
>      return ret;
> @@ -489,7 +489,8 @@ void paging_log_dirty_range(struct domain *d,
>   * These function pointers must not be followed with the log-dirty lock held.
>   */
>  void paging_log_dirty_init(struct domain *d,
> -                           int    (*enable_log_dirty)(struct domain *d),
> +                           int    (*enable_log_dirty)(struct domain *d,
> +                                                      bool_t log_global),
>                             int    (*disable_log_dirty)(struct domain *d),
>                             void   (*clean_dirty_bitmap)(struct domain *d))
>  {
> @@ -590,7 +591,7 @@ int paging_domctl(struct domain *d, 
> xen_domctl_shadow_op_t *sc,
>      case XEN_DOMCTL_SHADOW_OP_ENABLE_LOGDIRTY:
>          if ( hap_enabled(d) )
>              hap_logdirty_init(d);
> -        return paging_log_dirty_enable(d);
> +        return paging_log_dirty_enable(d, 1);
>
>      case XEN_DOMCTL_SHADOW_OP_OFF:
>          if ( paging_mode_log_dirty(d) )
> diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
> index 0bfa595..11c6b62 100644
> --- a/xen/arch/x86/mm/shadow/common.c
> +++ b/xen/arch/x86/mm/shadow/common.c
> @@ -3418,7 +3418,7 @@ shadow_write_p2m_entry(struct vcpu *v, unsigned long 
> gfn,
>  /* Shadow specific code which is called in paging_log_dirty_enable().
>   * Return 0 if no problem found.
>   */
> -int shadow_enable_log_dirty(struct domain *d)
> +int shadow_enable_log_dirty(struct domain *d, bool_t log_global)
>  {
>      int ret;
>
> diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
> index ea72db2..4ff89f0 100644
> --- a/xen/include/asm-x86/domain.h
> +++ b/xen/include/asm-x86/domain.h
> @@ -169,7 +169,7 @@ struct log_dirty_domain {
>      unsigned int   dirty_count;
>
>      /* functions which are paging mode specific */
> -    int            (*enable_log_dirty   )(struct domain *d);
> +    int            (*enable_log_dirty   )(struct domain *d, bool_t 
> log_global);
>      int            (*disable_log_dirty  )(struct domain *d);
>      void           (*clean_dirty_bitmap )(struct domain *d);
>  };
> diff --git a/xen/include/asm-x86/paging.h b/xen/include/asm-x86/paging.h
> index cd7ee3b..8dd2a61 100644
> --- a/xen/include/asm-x86/paging.h
> +++ b/xen/include/asm-x86/paging.h
> @@ -143,14 +143,15 @@ void paging_log_dirty_range(struct domain *d,
>                              uint8_t *dirty_bitmap);
>
>  /* enable log dirty */
> -int paging_log_dirty_enable(struct domain *d);
> +int paging_log_dirty_enable(struct domain *d, bool_t log_global);
>
>  /* disable log dirty */
>  int paging_log_dirty_disable(struct domain *d);
>
>  /* log dirty initialization */
>  void paging_log_dirty_init(struct domain *d,
> -                           int  (*enable_log_dirty)(struct domain *d),
> +                           int  (*enable_log_dirty)(struct domain *d,
> +                                                    bool_t log_global),
>                             int  (*disable_log_dirty)(struct domain *d),
>                             void (*clean_dirty_bitmap)(struct domain *d));
>
> diff --git a/xen/include/asm-x86/shadow.h b/xen/include/asm-x86/shadow.h
> index 852023d..348915e 100644
> --- a/xen/include/asm-x86/shadow.h
> +++ b/xen/include/asm-x86/shadow.h
> @@ -82,7 +82,7 @@ void shadow_teardown(struct domain *d);
>  void shadow_final_teardown(struct domain *d);
>
>  /* shadow code to call when log dirty is enabled */
> -int shadow_enable_log_dirty(struct domain *d);
> +int shadow_enable_log_dirty(struct domain *d, bool_t log_global);
>
>  /* shadow code to call when log dirty is disabled */
>  int shadow_disable_log_dirty(struct domain *d);
> --
> 1.7.1
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel

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