Date:   Fri, 3 Feb 2023 10:56:22 +0100
From:   Joerg Roedel <joro@8bytes.org>
To:     Sven Peter <sven@svenpeter.dev>
Cc:     Hector Martin <marcan@marcan.st>, Will Deacon <will@kernel.org>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Robin Murphy <robin.murphy@arm.com>, asahi@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/dart: Fix apple_dart_device_group for PCI groups
Message-ID: <Y9zaRgki00RypvvC@8bytes.org>
References: <20230128113532.94651-1-sven@svenpeter.dev>
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On Sat, Jan 28, 2023 at 12:35:32PM +0100, Sven Peter wrote:
> pci_device_group() can return an already existing IOMMU group if the PCI
> device's pagetables have to be shared with another one due to bus
> toplogy, isolation features and/or DMA alias quirks.
> apple_dart_device_group() however assumes that the group has just been
> created and overwrites its iommudata which will eventually lead to
> apple_dart_release_group leaving stale entries in sid2group.
> Fix that by merging the iommudata if the returned group already exists.
> 
> Fixes: f0b636804c7c ("iommu/dart: Clear sid2group entry when a group is freed")
> Signed-off-by: Sven Peter <sven@svenpeter.dev>
> ---
>  drivers/iommu/apple-dart.c | 51 ++++++++++++++++++++++++++++++++------
>  1 file changed, 44 insertions(+), 7 deletions(-)

Applied, thanks.