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From: James Gowans <jgowans@amazon.com>
To: <linux-kernel@vger.kernel.org>
CC: Eric Biederman <ebiederm@xmission.com>, <kexec@lists.infradead.org>,
	"Joerg Roedel" <joro@8bytes.org>, Will Deacon <will@kernel.org>,
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	Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>,
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Subject: [RFC 11/18] dma-iommu: Always enable deferred attaches for liveupdate
Date: Mon, 5 Feb 2024 12:01:56 +0000
Message-ID: <20240205120203.60312-12-jgowans@amazon.com>
In-Reply-To: <20240205120203.60312-1-jgowans@amazon.com>
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Seeing as translations are pre-enabled, all devices will be set for
deferred attach. The deferred attached actually has to be done when
doing DMA mapping for devices to work.

There may be a better way to do this be, for example, consulting the
context entry table and only deferring attach if there is a persisted
context table entry for this device.
---
 drivers/iommu/dma-iommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index e5d087bd6da1..76f916848f48 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1750,7 +1750,7 @@ void iommu_dma_compose_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
 
 static int iommu_dma_init(void)
 {
-	if (is_kdump_kernel())
+	if (is_kdump_kernel() || liveupdate)
 		static_branch_enable(&iommu_deferred_attach_enabled);
 
 	return iova_cache_get();
-- 
2.40.1