Re: [Qemu-devel] [PATCH v7 05/17] intel_iommu: simplify irq region translation

[David Gibson <david@gibson.dropbear.id.au>]

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On Tue, Feb 07, 2017 at 04:28:07PM +0800, Peter Xu wrote:
> Now we have a standalone memory region for MSI, all the irq region
> requests should be redirected there. Cleaning up the block with an
> assertion instead.
> 
> Reviewed-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  hw/i386/intel_iommu.c | 28 ++++++----------------------
>  1 file changed, 6 insertions(+), 22 deletions(-)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 50251c3..86d19bb 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -818,28 +818,12 @@ static void vtd_do_iommu_translate(VTDAddressSpace *vtd_as, PCIBus *bus,
>      bool writes = true;
>      VTDIOTLBEntry *iotlb_entry;
>  
> -    /* Check if the request is in interrupt address range */
> -    if (vtd_is_interrupt_addr(addr)) {
> -        if (is_write) {
> -            /* FIXME: since we don't know the length of the access here, we
> -             * treat Non-DWORD length write requests without PASID as
> -             * interrupt requests, too. Withoud interrupt remapping support,
> -             * we just use 1:1 mapping.
> -             */
> -            VTD_DPRINTF(MMU, "write request to interrupt address "
> -                        "gpa 0x%"PRIx64, addr);
> -            entry->iova = addr & VTD_PAGE_MASK_4K;
> -            entry->translated_addr = addr & VTD_PAGE_MASK_4K;
> -            entry->addr_mask = ~VTD_PAGE_MASK_4K;
> -            entry->perm = IOMMU_WO;
> -            return;
> -        } else {
> -            VTD_DPRINTF(GENERAL, "error: read request from interrupt address "
> -                        "gpa 0x%"PRIx64, addr);
> -            vtd_report_dmar_fault(s, source_id, addr, VTD_FR_READ, is_write);
> -            return;
> -        }
> -    }
> +    /*
> +     * We have standalone memory region for interrupt addresses, we
> +     * should never receive translation requests in this region.
> +     */
> +    assert(!vtd_is_interrupt_addr(addr));
> +
>      /* Try to fetch slpte form IOTLB */
>      iotlb_entry = vtd_lookup_iotlb(s, source_id, addr);
>      if (iotlb_entry) {

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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