Re: [Xen-devel] [BUG] After upgrade to Xen 4.12.0 iommu=no-igfx

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

Ping?

It would be very helpful for us in order to get this sorted out if you
could answer the questions below and try the new debug patch :).

On Fri, Jul 26, 2019 at 11:35:45AM +0200, Roger Pau Monné wrote:
> On Thu, Jul 25, 2019 at 05:47:19PM -0700, Roman Shaposhnik wrote:
> > Hi Roger!
> > 
> > With your patch (and build as a debug build) Xen crashes on boot
> > (which I guess was the point of your BUG_ON statement).
> 
> Yes, that's very weird, seems like entries are not added to the iommu
> page tables but I have no idea why, AFAICT this works fine on my
> system.
> 
> Do you have any patches on top of RELEASE-4.12.0?
> 
> I have another patch with more verbose output, could you give it a
> try? It's maybe going to be more chatty than the previous one.
> 
> I'm sorry to keep you testing stuff, but since I cannot reproduce this
> locally I have to rely on you to provide the debug output.
> 
> Thanks, Roger.
> ---8<---
> diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
> index b9bbb8f485..75f8359a99 100644
> --- a/xen/arch/x86/mm/p2m.c
> +++ b/xen/arch/x86/mm/p2m.c
> @@ -1331,7 +1331,7 @@ int set_identity_p2m_entry(struct domain *d, unsigned 
> long gfn_l,
>  
>      if ( !paging_mode_translate(p2m->domain) )
>      {
> -        if ( !need_iommu_pt_sync(d) )
> +        if ( !has_iommu_pt(d) )
>              return 0;
>          return iommu_legacy_map(d, _dfn(gfn_l), _mfn(gfn_l), PAGE_ORDER_4K,
>                                  IOMMUF_readable | IOMMUF_writable);
> @@ -1422,7 +1422,7 @@ int clear_identity_p2m_entry(struct domain *d, unsigned 
> long gfn_l)
>  
>      if ( !paging_mode_translate(d) )
>      {
> -        if ( !need_iommu_pt_sync(d) )
> +        if ( !has_iommu_pt(d) )
>              return 0;
>          return iommu_legacy_unmap(d, _dfn(gfn_l), PAGE_ORDER_4K);
>      }
> diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
> index 117b869b0c..214c5d515f 100644
> --- a/xen/drivers/passthrough/iommu.c
> +++ b/xen/drivers/passthrough/iommu.c
> @@ -291,8 +291,18 @@ int iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn,
>      unsigned long i;
>      int rc = 0;
>  
> +if (dfn_x(dfn) >= 0x8d800 && dfn_x(dfn) < 0x90000 )
> +{
> +    printk("<RMRR> iommu_map %#lx\n", dfn_x(dfn));
> +    process_pending_softirqs();
> +}
> +
>      if ( !iommu_enabled || !hd->platform_ops )
> +{
> +    printk("iommu_enabled: %d platform_ops %p\n",
> +           iommu_enabled, hd->platform_ops);
>          return 0;
> +}
>  
>      ASSERT(IS_ALIGNED(dfn_x(dfn), (1ul << page_order)));
>      ASSERT(IS_ALIGNED(mfn_x(mfn), (1ul << page_order)));
> diff --git a/xen/drivers/passthrough/vtd/iommu.c 
> b/xen/drivers/passthrough/vtd/iommu.c
> index 50a0e25224..8c3fcb50ae 100644
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -2009,12 +2009,33 @@ static int rmrr_identity_mapping(struct domain *d, 
> bool_t map,
>      if ( !map )
>          return -ENOENT;
>  
> +printk("<RMRR> mapping %#lx - %#lx\n", base_pfn, end_pfn);
>      while ( base_pfn < end_pfn )
>      {
>          int err = set_identity_p2m_entry(d, base_pfn, p2m_access_rw, flag);
> +        mfn_t mfn;
> +        unsigned int f;
>  
>          if ( err )
>              return err;
> +
> +err = intel_iommu_lookup_page(d, _dfn(base_pfn), &mfn, &f);
> +if ( err )
> +{
> +    printk("intel_iommu_lookup_page err: %d\n", err);
> +    BUG();
> +}
> +if ( base_pfn != mfn_x(mfn) )
> +{
> +    printk("base_pfn: %#lx mfn: %#lx\n", base_pfn, mfn_x(mfn));
> +    BUG();
> +}
> +if ( f != (IOMMUF_readable | IOMMUF_writable) )
> +{
> +    printk("flags: %#x\n", f);
> +    BUG();
> +}
> +
>          base_pfn++;
>      }
>  
> @@ -2263,6 +2284,7 @@ static void __hwdom_init setup_hwdom_rmrr(struct domain 
> *d)
>      u16 bdf;
>      int ret, i;
>  
> +printk("<RMRR> setting up regions\n");
>      pcidevs_lock();
>      for_each_rmrr_device ( rmrr, bdf, i )
>      {
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxxx
> https://lists.xenproject.org/mailman/listinfo/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel