Re: [v3 09/15] vt-d: Extend struct iremap_entry to support VT-d Posted-Interrupts

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 24/06/15 06:18, Feng Wu wrote:
> diff --git a/xen/drivers/passthrough/vtd/iommu.h b/xen/drivers/passthrough/vtd/iommu.h
> index e807253..49daa70 100644
> --- a/xen/drivers/passthrough/vtd/iommu.h
> +++ b/xen/drivers/passthrough/vtd/iommu.h
> @@ -289,29 +289,43 @@ struct dma_pte {
>  /* interrupt remap entry */
>  struct iremap_entry {
>    union {
> -    u64 lo_val;
> +    struct { u64 lo, hi; };
>      struct {
> -        u64 p       : 1,
> +        u16 p       : 1,
>              fpd     : 1,
>              dm      : 1,
>              rh      : 1,
>              tm      : 1,
>              dlm     : 3,
>              avail   : 4,
> -            res_1   : 4,
> -            vector  : 8,
> -            res_2   : 8,
> -            dst     : 32;
> -    }lo;
> -  };
> -  union {
> -    u64 hi_val;
> +            res_1   : 4;
> +        u8  vector;
> +        u8  res_2;
> +        u32 dst;
> +        u16 sid;
> +        u16 sq      : 2,
> +            svt     : 2,
> +            res_3   : 12;
> +        u32 res_4   : 32;

res_4 does not need to be a bitfield.

> +    } remap;
>      struct {
> -        u64 sid     : 16,
> -            sq      : 2,
> +        u16 p       : 1,
> +            fpd     : 1,
> +            res_1   : 6,
> +            avail   : 4,
> +            res_2   : 2,
> +            urg     : 1,
> +            im      : 1;

I think "im" needs exposing in both the post and remap unions, as it is
the bit which identifies which representation to use.

> +        u8  vector;
> +        u8  res_3;
> +        u32 res_4   : 6,
> +            pda_l   : 26;
> +        u16 sid;
> +        u16 sq      : 2,
>              svt     : 2,
> -            res_1   : 44;
> -    }hi;
> +            res_5   : 12;
> +        u32 pda_h;
> +    } post;
>    };
>  };
>  
> diff --git a/xen/drivers/passthrough/vtd/utils.c b/xen/drivers/passthrough/vtd/utils.c
> index bd14c02..a5fe237 100644
> --- a/xen/drivers/passthrough/vtd/utils.c
> +++ b/xen/drivers/passthrough/vtd/utils.c
> @@ -238,14 +238,14 @@ static void dump_iommu_info(unsigned char key)
>                  else
>                      p = &iremap_entries[i % (1 << IREMAP_ENTRY_ORDER)];
>  
> -                if ( !p->lo.p )
> +                if ( !p->remap.p )
>                      continue;
>                  printk("  %04x:  %x   %x  %04x %08x %02x    %x   %x  %x  %x  %x"
>                      "   %x %x\n", i,
> -                    (u32)p->hi.svt, (u32)p->hi.sq, (u32)p->hi.sid,
> -                    (u32)p->lo.dst, (u32)p->lo.vector, (u32)p->lo.avail,
> -                    (u32)p->lo.dlm, (u32)p->lo.tm, (u32)p->lo.rh,
> -                    (u32)p->lo.dm, (u32)p->lo.fpd, (u32)p->lo.p);
> +                    (u32)p->remap.svt, (u32)p->remap.sq, (u32)p->remap.sid,
> +                    (u32)p->remap.dst, (u32)p->remap.vector, (u32)p->remap.avail,
> +                    (u32)p->remap.dlm, (u32)p->remap.tm, (u32)p->remap.rh,
> +                    (u32)p->remap.dm, (u32)p->remap.fpd, (u32)p->remap.p);

This printing is only valid if "im" is 0.  As this series adds support
for the posted format, I would suggest you extend this debugging here to
deal with both formats.

~Andrew

>                  print_cnt++;
>              }
>              if ( iremap_entries )