On Thu, 22 Jul 2021 21:22:58 +0200 Christian Borntraeger <borntrae...@de.ibm.com> wrote:
> On 20.07.21 15:38, Will Deacon wrote: > > Hi again, folks, > > > > This is version two of the patch series I posted yesterday: > > > > https://lore.kernel.org/r/20210719123054.6844-1-w...@kernel.org > > > > The only changes since v1 are: > > > > * Squash patches 2 and 3, amending the commit message accordingly > > * Add Reviewed-by and Tested-by tags from Christoph and Claire (thanks!) > > > > I'd usually leave it a bit longer between postings, but since this fixes > > issues with patches in -next I thought I'd spin a new version immediately. > > > > Cheers, > > FWIW, I just bisected virtio-errors with secure execution mode > qemu-system-s390x: virtio-serial-bus: Unexpected port id 4205794771 for > device virtio-serial0.0 > > to > commit 903cd0f315fe426c6a64c54ed389de0becb663dc > Author: Claire Chang <tien...@chromium.org> > Date: Thu Jun 24 23:55:20 2021 +0800 > > swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing > > Unfortunately this patch series does NOT fix this issue, so it seems that > even more > things are broken. > > Any idea what else might be broken? I've done some debugging, and I think I know what is going on. Since that commit we need to set force_swiotlb before the swiotlb itself is initialized. So the patch below should fix the problem. --------------------8<------------------------------------- From: Halil Pasic <pa...@linux.ibm.com> Date: Fri, 23 Jul 2021 02:57:06 +0200 Subject: [PATCH 1/1] s390/pv: fix the forcing of the swiotlb Since commit 903cd0f315fe ("swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing") if code sets swiotlb_force it needs to do so before the swiotlb is initialised. Otherwise io_tlb_default_mem->force_bounce will not get set to true, and devices that use (the default) swiotlb will not bounce despite switolb_force having the value of SWIOTLB_FORCE. Let us restore swiotlb functionality for PV by fulfilling this new requirement. Signed-off-by: Halil Pasic <pa...@linux.ibm.com> --- arch/s390/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 8ac710de1ab1..07bbee9b7320 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -186,9 +186,9 @@ static void pv_init(void) return; /* make sure bounce buffers are shared */ + swiotlb_force = SWIOTLB_FORCE; swiotlb_init(1); swiotlb_update_mem_attributes(); - swiotlb_force = SWIOTLB_FORCE; } void __init mem_init(void) -- 2.29.2 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
