Re: [Qemu-devel] [PATCH v7 19/20] hw/arm/smmuv3: [not for upstream] add SMMU_CMD_TLBI_NH_VA_AM handling

[Peter Maydell]

On 1 September 2017 at 18:21, Eric Auger <address@hidden> wrote:
> SMMUV3 does not support any IOVA range TLBI command:
> SMMU_CMD_TLBI_NH_VA invalidates TLB entries by page.
> That's an issue when running DPDK on guest. DPDK uses
> hugepages but each time a hugepage is mapped on guest side,
> a storm of SMMU_CMD_TLBI_NH_VA commands get sent by the
> guest smmuv3 driver and trapped by QEMU for VFIO replay.
>
> Let's get prepared to handle implementation defined commands,
> SMMU_CMD_TLBI_NH_VA_VM, which invalidate a range of IOVAs.
>
> Upon this command, we notify the whole range in one host.
>
> Signed-off-by: Eric Auger <address@hidden>

Definite NACK for this, I'm afraid. We should emulate the
hardware, not new things of our own devising.

thanks
-- PMM