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From:   Nadav Amit <namit@vmware.com>
To:     Jon Pan-Doh <pandoh@google.com>
CC:     Joerg Roedel <joro@8bytes.org>,
        Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
        Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        "iommu@lists.linux.dev" <iommu@lists.linux.dev>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Sudheer Dantuluri <dantuluris@google.com>,
        Gary Zibrat <gzibrat@google.com>
Subject: Re: [PATCH] iommu/amd: Fix domain flush size when syncing iotlb
Thread-Topic: [PATCH] iommu/amd: Fix domain flush size when syncing iotlb
Thread-Index: AQHZeH5MzL7QCyjHEUuk1s9n/e4s+68+FGgA
Date:   Wed, 26 Apr 2023 21:04:43 +0000
Message-ID: <7F4D224A-A6A0-46BF-B008-A9E488257639@vmware.com>
References: <20230426203256.237116-1-pandoh@google.com>
In-Reply-To: <20230426203256.237116-1-pandoh@google.com>
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> On Apr 26, 2023, at 1:32 PM, Jon Pan-Doh <pandoh@google.com> wrote:
>=20
> When running on an AMD vIOMMU, we observed multiple invalidations (of
> decreasing power of 2 aligned sizes) when unmapping a single page.
>=20
> Domain flush takes gather bounds (end-start) as size param. However,
> gather->end is defined as the last inclusive address (start + size - 1).
> This leads to an off by 1 error.
>=20
> With this patch, verified that 1 invalidation occurs when unmapping a
> single page.
>=20
> Fixes: a270be1b3fdf ("iommu/amd: Use only natural aligned flushes in a VM=
")
> Signed-off-by: Jon Pan-Doh <pandoh@google.com>
> Tested-by: Sudheer Dantuluri <dantuluris@google.com>
> Suggested-by: Gary Zibrat <gzibrat@google.com>
>=20

Sorry for that.

Acked-by: Nadav Amit <namit@vmware.com>