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Re: [Qemu-ppc] [PATCH] spapr: Only report host/guest IOMMU page size mis
From: |
Thomas Huth |
Subject: |
Re: [Qemu-ppc] [PATCH] spapr: Only report host/guest IOMMU page size mismatches on KVM |
Date: |
Tue, 4 Jul 2017 16:04:13 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 |
On 04.07.2017 15:54, David Gibson wrote:
> We print a warning if the spapr IOMMU isn't configured to support a page
> size matching the host page size backing RAM. When that's the case we need
> more complex logic to translate VFIO mappings, which is slower.
>
> But, it's not so slow that it would be at all noticeable against the
> general slowness of TCG. So, only warn when using KVM. This removes some
> noisy and unhelpful warnings from make check on hosts with page sizes
> which typically differ from those on POWER (e.g. Sparc).
>
> Reported-by: Peter Maydell <address@hidden>
> Signed-off-by: David Gibson <address@hidden>
> ---
> hw/ppc/spapr_pci.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index cc1588d..a52dcf8 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1745,7 +1745,8 @@ static void spapr_phb_realize(DeviceState *dev, Error
> **errp)
> }
>
> /* DMA setup */
> - if ((sphb->page_size_mask & qemu_getrampagesize()) == 0) {
> + if (((sphb->page_size_mask & qemu_getrampagesize()) == 0)
> + && kvm_enabled()) {
Since you've put me on CC: ... too much parenthesis for my taste ;-)
Apart from that,
Reviewed-by: Thomas Huth <address@hidden>