From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f173.google.com (mail-dy1-f173.google.com [74.125.82.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 039654D2EE6 for ; Mon, 11 May 2026 21:10:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778533849; cv=none; b=gdK4y7OJGP5cg1WkQgTEvae8e6Klc5bI9RAtzBntROU4L41D+l6SRyleBOVyDAoojeN3/B/eAcxVUnv7bdo1q5mFY1UOmybmLam1PqSr5d5jzM8YoP+rS4/913tujZne9sLAXCNYIjHQO9pAQdX2seeLLHIJcbfJclwmNsI4JMM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778533849; c=relaxed/simple; bh=OicPgjnrqDPLO3PrCx45/s1FF7/nTgJfea0D9L2qSMU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fZuMsKCdwhzTaeASbLFFJzKTzYVZzdk8X1UfuNLcfMK0GJ4nKoG8xQdnbtcz9LmFt48z4Zow6OEmZQgVdLvIKE/IzqhgMSzm9HugVwN2FZODKuJ5w944mZ5Nmlo/FMWj4DS5c83CuOE7FOnWgpI5DotjNMOzn6YyihVzqqFbgvg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=wfvLf8OZ; arc=none smtp.client-ip=74.125.82.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wfvLf8OZ" Received: by mail-dy1-f173.google.com with SMTP id 5a478bee46e88-2ee990e8597so8326381eec.1 for ; Mon, 11 May 2026 14:10:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778533847; x=1779138647; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=tJUZ+9h7cLwAojaR2mrUsKXNC1lI0aWmSJMdNn306BU=; b=wfvLf8OZByRE1gKDoIEeaOAaNUlVfsFaXi81se45zNgzEZ5xsDb9+tNkShZKNBpUl8 mnC4aiT76WjH0e3z8AyRTcxunZ0hd6V12r/NLaC84Lryt1rGdEw5TNn1wiKW1SprL3UQ /aUW+UOjUP5hZadvNgsrfWkGGPRVFtZmQikJJiZA1evw1MWkUg8jF4fG5DU/XAuU7IOd UipidrDciAR1UvgoRXNZxrzr82qZz0wPbEi+UWcDeFFVCKTQvz9sNvgQ+f4F25tgDFBA 5VjpYwvBh0DtAwKRmmoJi/I8iesEpIvZRY81VQhTZAWZULkb5eb3aN9LF5xa4APwQ/te gFMQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778533847; x=1779138647; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tJUZ+9h7cLwAojaR2mrUsKXNC1lI0aWmSJMdNn306BU=; b=LBjOGy7Qy0qROjytD98frCLnhGm+3i/iqdSADmpiqdRSGZqnOgM4amuDuOpibpty5N penPvewbhlcxBP6c+jHzaMJpNFHStBe9vxQqi/H879dD8uzOQQZfz/Phdafd1RnKBDM4 pWCtL1kM0ooKJzcVxd4/Di4z9wGPsfa7Fm+IPMf7xmmLP4CCg6KIx1+75lQyr4hz0vm+ GwEVtOmQfpj5EK/FObRetQP/MiDBaYWxe3HwZu+6K8Vr2mPUqfzo3biPD1jbolSojSIw F5zg+UPaIvUkCyB85jhornWBOWfFG9yt3/1w6mid70wJMKHgQiQ1zVABW/uOwtViqP7T cWUw== X-Forwarded-Encrypted: i=1; AFNElJ/PFti/XgJorSZ6MGW6mER4A6GiycTN1HyI+TcOxRoqzNnmK6ZaxjHCh0hjqvCisMjCms8=@vger.kernel.org X-Gm-Message-State: AOJu0Yz8e199FkP8UsyU+I9FXJz051na0hkVS3mKru+oxisd8ueM2oz+ vm6Wsc+Ft8UEDHkF4S81nXjOKtBaoIByoqs9L0kZ774WrQbguaS7BE0mQddKIhHjvQ== X-Gm-Gg: Acq92OGWUDuryJhoe/h1WHnuVZiQNkkbzK9Wbt/Deq+OBKT+LDEJ9qOHBX/V2yzGMLK IXAd4Oup2kyVrd8UdNHeeHWhk7DvE0F4eT615L1jFSX+UAuQGCTPtpWNxZaipWjgd97OajrQatv VqVNYYN+TsiW8AapFRRSzVzTpInCWkszo7AmXH3H+Cg7yeito6/VPhwNYOdMnlDaU4rRjSS+Ru9 DQOzwxaxwRBmRone23NQb7438PGAIeGLXf8YT9g5O1IZ/T6TuBC5DZtJ7/z8U+LDeEPd9uFYEmB g9kl8AyixZ2zi1WnyFVdjTWSD5d907lJT0FMxz32WRk5F6TY2TZtrUCeK84mIttrGqDyaUNhUgz N8/EbBVhRy7MInXgHGweEhLyRYwQEVH1F+BDGVez0RSCuj+ZjBf4zIHkREHCtQ60rFg7206sY0U 4D3zIvxOL4y+iOMxFFgw74ffVQsZM6MIiuait30i14cApFE1r9Kso8vu04uC+Ep+0fAF+zZU051 +v8492beVw= X-Received: by 2002:a05:7301:400b:b0:2de:cc07:e99 with SMTP id 5a478bee46e88-2ffd51cd78bmr154725eec.7.1778533846490; Mon, 11 May 2026 14:10:46 -0700 (PDT) Received: from google.com (56.149.168.34.bc.googleusercontent.com. [34.168.149.56]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2f91004b6a2sm13584757eec.0.2026.05.11.14.10.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 May 2026 14:10:46 -0700 (PDT) Date: Mon, 11 May 2026 21:10:42 +0000 From: David Matlack To: Samiullah Khawaja Cc: Aex Williamson , Shuah Khan , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH 2/2] vfio: selftests: Add iommufd multi iommu test Message-ID: References: <20260505221518.619123-1-skhawaja@google.com> <20260505221518.619123-3-skhawaja@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On 2026-05-11 08:53 PM, Samiullah Khawaja wrote: > On Fri, May 08, 2026 at 08:14:08PM +0000, David Matlack wrote: > > On 2026-05-05 10:14 PM, Samiullah Khawaja wrote: > > > Add a test for iommufd to verify creation of multiple iommus using an > > > already setup iommufd and switch between them. > > > > > > Signed-off-by: Samiullah Khawaja > > > --- > > > tools/testing/selftests/vfio/Makefile | 1 + > > > .../vfio/vfio_iommufd_multi_iommu_test.c | 203 ++++++++++++++++++ > > > 2 files changed, 204 insertions(+) > > > create mode 100644 tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c > > > > > > diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile > > > index 0684932d91bf..24bdeaad590f 100644 > > > --- a/tools/testing/selftests/vfio/Makefile > > > +++ b/tools/testing/selftests/vfio/Makefile > > > @@ -8,6 +8,7 @@ else > > > CFLAGS = $(KHDR_INCLUDES) > > > TEST_GEN_PROGS += vfio_dma_mapping_test > > > TEST_GEN_PROGS += vfio_dma_mapping_mmio_test > > > +TEST_GEN_PROGS += vfio_iommufd_multi_iommu_test > > > TEST_GEN_PROGS += vfio_iommufd_setup_test > > > TEST_GEN_PROGS += vfio_pci_device_test > > > TEST_GEN_PROGS += vfio_pci_device_init_perf_test > > > diff --git a/tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c b/tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c > > > new file mode 100644 > > > index 000000000000..7199c662637c > > > --- /dev/null > > > +++ b/tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c > > > @@ -0,0 +1,203 @@ > > > +// SPDX-License-Identifier: GPL-2.0-only > > > +#include > > > +#include > > > + > > > +#include > > > +#include > > > + > > > +#include > > > + > > > +#include "kselftest_harness.h" > > > + > > > +static const char *device_bdf; > > > + > > > +#define IOMMU_DEFAULT 0 > > > +#define IOMMU_WITH_PT 1 > > > +#define IOMMU_WITHOUT_PT 2 > > > + > > > +static void region_setup(struct iommu *iommu, > > > + struct iova_allocator *iova_allocator, > > > + struct dma_region *region, u64 size) > > > +{ > > > + const int flags = MAP_SHARED | MAP_ANONYMOUS; > > > + const int prot = PROT_READ | PROT_WRITE; > > > + void *vaddr; > > > + > > > + vaddr = mmap(NULL, size, prot, flags, -1, 0); > > > + VFIO_ASSERT_NE(vaddr, MAP_FAILED); > > > + > > > + region->vaddr = vaddr; > > > + region->iova = iova_allocator_alloc(iova_allocator, size); > > > + region->size = size; > > > + > > > + iommu_map(iommu, region); > > > +} > > > + > > > +static void region_teardown(struct iommu *iommu, struct dma_region *region) > > > +{ > > > + iommu_unmap(iommu, region); > > > + VFIO_ASSERT_EQ(munmap(region->vaddr, region->size), 0); > > > +} > > > > Can you create library helpers in the library to share with > > vfio_pci_driver_test.c? > > > > dma_region_setup() > > dma_region_teardown() > > I thought it is ok to duplicate this as each test (in future) might have > different mapping requirements? we might have memfd, guest_memfd, > dma_buf with various mapping strategies for different usecases? > > Or you are thinking of a basic helper that can be used by tests if they > are not doing anything fancy? We have 2 tests now that need the same code to setup their regions so we might as well share it. As new and more complex use-cases arise we can figure out how to support them (per-test logic or fancier library support). > > > +TEST_F(vfio_iommufd_multi_iommu_test, memcpy) > > > +{ > > > + struct dma_region memcpy_region1, driver_region1; > > > + struct dma_region memcpy_region2, driver_region2; > > > + struct iommu *iommu1; > > > + struct iommu *iommu2; > > > + > > > + iommu1 = setup_variant_iommu(self->iommu, self->device->dev_id, > > > + variant->start_iommu); > > > + if (iommu1 != self->iommu) { > > > + memcpy_region1 = self->memcpy_region; > > > + driver_region1 = self->device->driver.region; > > > + > > > + iommu_map(iommu1, &memcpy_region1); > > > > Can you make a helper to copy dma_region into a new iommu? It should set > > up the new struct dma_region based on the old one, re-initialize the > > link field, and then call iommu_map(). > > Can you please clarify, I didn't get it completely. so basically > something that can be called like following? > > setup_copy_dma_regions(self, iommu1, &memcpy_region1, &driver_region1); I was thinking something like this exposed by lib/iommu.c: void iommu_copy_mapping(struct iommu *iommu, struct dma_region *new_region, struct dma_region *existing_region) { *new_region = *existing_region; INIT_LIST_HEAD(&new_region->link); iommu_map(iommu, new_region); } And then in the test you just do: if (iommu1 != self->iommu) iommu_copy_mapping(iommu1, memcpy_region1, self->memcpy_region);