Re: [Xen-devel] [PATCH] VT-d: print_vtd_entries() should cope with superpages

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

> From: Jan Beulich [mailto:JBeulich@xxxxxxxx]
> Sent: Friday, February 27, 2015 5:52 PM
> 
> Even if VT-d code alone (i.e. when not sharing tables with EPT) still
> doesn't support superpages, this function - invoked upon DMA remapping
> faults - needs to cope with such.
> 
> While at it also replace a few more plain numbers with suitable named
> constants.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>

> 
> --- a/xen/drivers/passthrough/vtd/iommu.h
> +++ b/xen/drivers/passthrough/vtd/iommu.h
> @@ -268,18 +268,22 @@ struct dma_pte {
>  };
>  #define DMA_PTE_READ (1)
>  #define DMA_PTE_WRITE (2)
> +#define DMA_PTE_PROT (DMA_PTE_READ | DMA_PTE_WRITE)
> +#define DMA_PTE_SP   (1 << 7)
>  #define DMA_PTE_SNP  (1 << 11)
>  #define dma_clear_pte(p)    do {(p).val = 0;} while(0)
>  #define dma_set_pte_readable(p) do {(p).val |= DMA_PTE_READ;} while(0)
>  #define dma_set_pte_writable(p) do {(p).val |= DMA_PTE_WRITE;} while(0)
> -#define dma_set_pte_superpage(p) do {(p).val |= (1 << 7);} while(0)
> +#define dma_set_pte_superpage(p) do {(p).val |= DMA_PTE_SP;} while(0)
>  #define dma_set_pte_snp(p)  do {(p).val |= DMA_PTE_SNP;} while(0)
> -#define dma_set_pte_prot(p, prot) \
> -            do {(p).val = ((p).val & ~3) | ((prot) & 3); } while (0)
> +#define dma_set_pte_prot(p, prot) do { \
> +        (p).val = ((p).val & ~DMA_PTE_PROT) | ((prot) & DMA_PTE_PROT);
> \
> +    } while (0)
>  #define dma_pte_addr(p) ((p).val & PADDR_MASK & PAGE_MASK_4K)
>  #define dma_set_pte_addr(p, addr) do {\
>              (p).val |= ((addr) & PAGE_MASK_4K); } while (0)
> -#define dma_pte_present(p) (((p).val & 3) != 0)
> +#define dma_pte_present(p) (((p).val & DMA_PTE_PROT) != 0)
> +#define dma_pte_superpage(p) (((p).val & DMA_PTE_SP) != 0)
> 
>  /* interrupt remap entry */
>  struct iremap_entry {
> --- a/xen/drivers/passthrough/vtd/utils.c
> +++ b/xen/drivers/passthrough/vtd/utils.c
> @@ -179,6 +179,8 @@ void print_vtd_entries(struct iommu *iom
>              printk("    l%d[%x] not present\n", level, l_index);
>              break;
>          }
> +        if ( dma_pte_superpage(pte) )
> +            break;
>          val = dma_pte_addr(pte);
>      } while ( --level );
>  }
> 
> 


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