Re: [Xen-devel] [PATCH] VT-d: suppress individual flushes during hwdom setup

[Paul Durrant <Paul.Durrant@xxxxxxxxxx>]

> -----Original Message-----
> From: Xen-devel [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxxx] On Behalf Of 
> Jan Beulich
> Sent: 02 May 2019 13:28
> To: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
> Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> Subject: [Xen-devel] [PATCH] VT-d: suppress individual flushes during hwdom 
> setup
> 
> There's an invocation of iommu_flush_all() immediately afterwards.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -1310,8 +1310,11 @@ static void __hwdom_init intel_iommu_hwd
> 
>      setup_hwdom_pci_devices(d, setup_hwdom_device);
>      setup_hwdom_rmrr(d);
> +
>      /* Make sure workarounds are applied before enabling the IOMMU(s). */
> +    this_cpu(iommu_dont_flush_iotlb) = true;
>      arch_iommu_hwdom_init(d);
> +    this_cpu(iommu_dont_flush_iotlb) = false;

There should be no need for this. arch_iommu_hwdom_init() is using iommu_map(), 
which no longer does implicit flushing.

  Paul

> 
>      if ( iommu_flush_all() )
>          printk(XENLOG_WARNING VTDPREFIX
> 
> 
> 
> _______________________________________________
> 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