From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.19 48/52] iommu/vt-d: Check capability before disabling protected memory Date: Fri, 29 Mar 2019 20:52:55 -0400 Message-ID: <20190330005301.26868-48-sashal@kernel.org> References: <20190330005301.26868-1-sashal@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190330005301.26868-1-sashal-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Sasha Levin , Joerg Roedel , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, mark gross List-Id: iommu@lists.linux-foundation.org From: Lu Baolu [ Upstream commit 5bb71fc790a88d063507dc5d445ab8b14e845591 ] The spec states in 10.4.16 that the Protected Memory Enable Register should be treated as read-only for implementations not supporting protected memory regions (PLMR and PHMR fields reported as Clear in the Capability register). Cc: Jacob Pan Cc: mark gross Suggested-by: Ashok Raj Fixes: f8bab73515ca5 ("intel-iommu: PMEN support") Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/intel-iommu.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 2b8f5ebae821..603bf5233a99 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1624,6 +1624,9 @@ static void iommu_disable_protect_mem_regions(struct intel_iommu *iommu) u32 pmen; unsigned long flags; + if (!cap_plmr(iommu->cap) && !cap_phmr(iommu->cap)) + return; + raw_spin_lock_irqsave(&iommu->register_lock, flags); pmen = readl(iommu->reg + DMAR_PMEN_REG); pmen &= ~DMA_PMEN_EPM; -- 2.19.1