From: David Gibson <david@gibson.dropbear.id.au>
To: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: linuxppc-dev@lists.ozlabs.org,
Alex Williamson <alex.williamson@redhat.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Gavin Shan <gwshan@linux.vnet.ibm.com>,
Paul Mackerras <paulus@samba.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH kernel v11 23/34] powerpc/iommu/powernv: Release replaced TCE
Date: Mon, 1 Jun 2015 17:04:49 +1000 [thread overview]
Message-ID: <20150601070449.GN22789@voom.redhat.com> (raw)
In-Reply-To: <1432889098-22924-24-git-send-email-aik@ozlabs.ru>
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On Fri, May 29, 2015 at 06:44:47PM +1000, Alexey Kardashevskiy wrote:
> At the moment writing new TCE value to the IOMMU table fails with EBUSY
> if there is a valid entry already. However PAPR specification allows
> the guest to write new TCE value without clearing it first.
>
> Another problem this patch is addressing is the use of pool locks for
> external IOMMU users such as VFIO. The pool locks are to protect
> DMA page allocator rather than entries and since the host kernel does
> not control what pages are in use, there is no point in pool locks and
> exchange()+put_page(oldtce) is sufficient to avoid possible races.
>
> This adds an exchange() callback to iommu_table_ops which does the same
> thing as set() plus it returns replaced TCE and DMA direction so
> the caller can release the pages afterwards. The exchange() receives
> a physical address unlike set() which receives linear mapping address;
> and returns a physical address as the clear() does.
>
> This implements exchange() for P5IOC2/IODA/IODA2. This adds a requirement
> for a platform to have exchange() implemented in order to support VFIO.
>
> This replaces iommu_tce_build() and iommu_clear_tce() with
> a single iommu_tce_xchg().
>
> This makes sure that TCE permission bits are not set in TCE passed to
> IOMMU API as those are to be calculated by platform code from
> DMA direction.
>
> This moves SetPageDirty() to the IOMMU code to make it work for both
> VFIO ioctl interface in in-kernel TCE acceleration (when it becomes
> available later).
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> [aw: for the vfio related changes]
> Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2015-06-01 7:04 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-29 8:44 [PATCH kernel v11 00/34] powerpc/iommu/vfio: Enable Dynamic DMA windows Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 01/34] powerpc/eeh/ioda2: Use device::iommu_group to check IOMMU group Alexey Kardashevskiy
2015-06-01 3:40 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 02/34] powerpc/iommu/powernv: Get rid of set_iommu_table_base_and_group Alexey Kardashevskiy
2015-06-01 3:47 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 03/34] powerpc/powernv/ioda: Clean up IOMMU group registration Alexey Kardashevskiy
2015-06-01 3:55 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 04/34] powerpc/iommu: Put IOMMU group explicitly Alexey Kardashevskiy
2015-06-01 3:58 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 05/34] powerpc/iommu: Always release iommu_table in iommu_free_table() Alexey Kardashevskiy
2015-06-01 4:03 ` David Gibson
2015-06-05 0:10 ` Gavin Shan
2015-05-29 8:44 ` [PATCH kernel v11 06/34] vfio: powerpc/spapr: Move page pinning from arch code to VFIO IOMMU driver Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 07/34] vfio: powerpc/spapr: Check that IOMMU page is fully contained by system page Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 08/34] vfio: powerpc/spapr: Use it_page_size Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 09/34] vfio: powerpc/spapr: Move locked_vm accounting to helpers Alexey Kardashevskiy
2015-06-01 4:28 ` David Gibson
2015-06-03 11:11 ` Alexey Kardashevskiy
2015-06-04 1:00 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 10/34] vfio: powerpc/spapr: Disable DMA mappings on disabled container Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 11/34] vfio: powerpc/spapr: Moving pinning/unpinning to helpers Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 12/34] vfio: powerpc/spapr: Rework groups attaching Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 13/34] powerpc/powernv: Do not set "read" flag if direction==DMA_NONE Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 14/34] powerpc/iommu: Move tce_xxx callbacks from ppc_md to iommu_table Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 15/34] powerpc/powernv/ioda/ioda2: Rework TCE invalidation in tce_build()/tce_free() Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 16/34] powerpc/spapr: vfio: Replace iommu_table with iommu_table_group Alexey Kardashevskiy
2015-06-01 5:11 ` David Gibson
2015-06-05 0:19 ` Gavin Shan
2015-05-29 8:44 ` [PATCH kernel v11 17/34] powerpc/spapr: vfio: Switch from iommu_table to new iommu_table_group Alexey Kardashevskiy
2015-06-01 6:24 ` David Gibson
2015-06-04 9:14 ` Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 18/34] vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control Alexey Kardashevskiy
2015-06-01 6:34 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 19/34] powerpc/iommu: Fix IOMMU ownership control functions Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 20/34] powerpc/powernv/ioda2: Move TCE kill register address to PE Alexey Kardashevskiy
2015-06-01 6:47 ` David Gibson
2015-06-05 0:22 ` Gavin Shan
2015-05-29 8:44 ` [PATCH kernel v11 21/34] powerpc/powernv/ioda2: Add TCE invalidation for all attached groups Alexey Kardashevskiy
2015-06-01 6:49 ` David Gibson
2015-06-05 0:27 ` Gavin Shan
2015-06-05 2:54 ` Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 22/34] powerpc/powernv: Implement accessor to TCE entry Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 23/34] powerpc/iommu/powernv: Release replaced TCE Alexey Kardashevskiy
2015-06-01 7:04 ` David Gibson [this message]
2015-05-29 8:44 ` [PATCH kernel v11 24/34] powerpc/powernv/ioda2: Rework iommu_table creation Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 25/34] powerpc/powernv/ioda2: Introduce helpers to allocate TCE pages Alexey Kardashevskiy
2015-06-01 7:29 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 26/34] powerpc/powernv/ioda2: Introduce pnv_pci_ioda2_set_window Alexey Kardashevskiy
2015-06-01 23:30 ` David Gibson
2015-06-03 11:18 ` Alexey Kardashevskiy
2015-05-29 8:44 ` [PATCH kernel v11 27/34] powerpc/powernv: Implement multilevel TCE tables Alexey Kardashevskiy
2015-06-01 23:50 ` David Gibson
2015-06-03 11:27 ` Alexey Kardashevskiy
2015-06-04 1:16 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 28/34] vfio: powerpc/spapr: powerpc/powernv/ioda: Define and implement DMA windows API Alexey Kardashevskiy
2015-06-02 0:24 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 29/34] powerpc/powernv/ioda2: Use new helpers to do proper cleanup on PE release Alexey Kardashevskiy
2015-06-02 0:47 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 30/34] powerpc/iommu/ioda2: Add get_table_size() to calculate the size of future table Alexey Kardashevskiy
2015-06-02 0:54 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 31/34] vfio: powerpc/spapr: powerpc/powernv/ioda2: Use DMA windows API in ownership control Alexey Kardashevskiy
2015-06-02 1:09 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 32/34] powerpc/mmu: Add userspace-to-physical addresses translation cache Alexey Kardashevskiy
2015-06-02 1:40 ` David Gibson
2015-05-29 8:44 ` [PATCH kernel v11 33/34] vfio: powerpc/spapr: Register memory and define IOMMU v2 Alexey Kardashevskiy
2015-06-02 4:17 ` David Gibson
2015-06-03 11:40 ` Alexey Kardashevskiy
2015-06-04 1:20 ` David Gibson
2015-06-05 0:01 ` Gavin Shan
2015-05-29 8:44 ` [PATCH kernel v11 34/34] vfio: powerpc/spapr: Support Dynamic DMA windows Alexey Kardashevskiy
2015-06-02 4:37 ` David Gibson
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