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Re: [Qemu-stable] [PATCH] intel_iommu: handle invalid ce for shadow sync
From: |
Peter Xu |
Subject: |
Re: [Qemu-stable] [PATCH] intel_iommu: handle invalid ce for shadow sync |
Date: |
Fri, 28 Sep 2018 13:23:25 +0800 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
On Thu, Sep 13, 2018 at 03:55:17PM +0800, Peter Xu wrote:
> There are two callers for vtd_sync_shadow_page_table_range(), one
> provided a valid context entry and one not. Move that fetching
> operation into the caller vtd_sync_shadow_page_table() where we need to
> fetch the context entry.
>
> Meanwhile, we should handle VTD_FR_CONTEXT_ENTRY_P properly when
> synchronizing shadow page tables. Having invalid context entry there is
> perfectly valid when we move a device out of an existing domain. When
> that happens, instead of posting an error we invalidate the whole region.
>
> Without this patch, QEMU will crash if we do these steps:
>
> (1) start QEMU with VT-d IOMMU and two 10G NICs (ixgbe)
> (2) bind the NICs with vfio-pci in the guest
> (3) start testpmd with the NICs applied
> (4) stop testpmd
> (5) rebind the NIC back to ixgbe kernel driver
>
> The patch should fix it.
Ping?
Regards,
--
Peter Xu