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From: Barret Rhoden <brho@google.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>, Yian Chen <yian.chen@intel.com>,
	Sohil Mehta <sohil.mehta@intel.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	x86@kernel.org
Subject: [PATCH 2/3] iommu/vt-d: treat unmapped RMRR entries as sane
Date: Wed, 11 Dec 2019 14:46:05 -0500	[thread overview]
Message-ID: <20191211194606.87940-3-brho@google.com> (raw)
In-Reply-To: <20191211194606.87940-1-brho@google.com>

The RMRR sanity check is to confirm that the memory pointed to by the
RMRR entry is not used by the kernel.  e820 RESERVED memory will not be
used.  However, there are ranges of physical memory that are not covered
by the e820 table at all.  The kernel will not use this memory, either.

This commit expands the sanity check to treat memory that is not in any
e820 entry as safe.

Signed-off-by: Barret Rhoden <brho@google.com>
---
 arch/x86/include/asm/iommu.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/iommu.h b/arch/x86/include/asm/iommu.h
index bf1ed2ddc74b..7e9f0c2f975f 100644
--- a/arch/x86/include/asm/iommu.h
+++ b/arch/x86/include/asm/iommu.h
@@ -20,6 +20,8 @@ arch_rmrr_sanity_check(struct acpi_dmar_reserved_memory *rmrr)
 
 	if (e820__mapped_all(start, end, E820_TYPE_RESERVED))
 		return 0;
+	if (!e820__mapped_any(start, end, 0))
+		return 0;
 
 	pr_err(FW_BUG "No firmware reserved region can cover this RMRR [%#018Lx-%#018Lx], contact BIOS vendor for fixes\n",
 	       start, end - 1);
-- 
2.24.0.525.g8f36a354ae-goog


WARNING: multiple messages have this Message-ID (diff)
From: Barret Rhoden via iommu <iommu@lists.linux-foundation.org>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	 "H. Peter Anvin" <hpa@zytor.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>,  Yian Chen <yian.chen@intel.com>,
	Sohil Mehta <sohil.mehta@intel.com>
Cc: iommu@lists.linux-foundation.org, x86@kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] iommu/vt-d: treat unmapped RMRR entries as sane
Date: Wed, 11 Dec 2019 14:46:05 -0500	[thread overview]
Message-ID: <20191211194606.87940-3-brho@google.com> (raw)
In-Reply-To: <20191211194606.87940-1-brho@google.com>

The RMRR sanity check is to confirm that the memory pointed to by the
RMRR entry is not used by the kernel.  e820 RESERVED memory will not be
used.  However, there are ranges of physical memory that are not covered
by the e820 table at all.  The kernel will not use this memory, either.

This commit expands the sanity check to treat memory that is not in any
e820 entry as safe.

Signed-off-by: Barret Rhoden <brho@google.com>
---
 arch/x86/include/asm/iommu.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/iommu.h b/arch/x86/include/asm/iommu.h
index bf1ed2ddc74b..7e9f0c2f975f 100644
--- a/arch/x86/include/asm/iommu.h
+++ b/arch/x86/include/asm/iommu.h
@@ -20,6 +20,8 @@ arch_rmrr_sanity_check(struct acpi_dmar_reserved_memory *rmrr)
 
 	if (e820__mapped_all(start, end, E820_TYPE_RESERVED))
 		return 0;
+	if (!e820__mapped_any(start, end, 0))
+		return 0;
 
 	pr_err(FW_BUG "No firmware reserved region can cover this RMRR [%#018Lx-%#018Lx], contact BIOS vendor for fixes\n",
 	       start, end - 1);
-- 
2.24.0.525.g8f36a354ae-goog

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  parent reply	other threads:[~2019-12-11 19:46 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-11 19:46 [PATCH 0/3] iommu/vt-d bad RMRR workarounds Barret Rhoden
2019-12-11 19:46 ` Barret Rhoden via iommu
2019-12-11 19:46 ` [PATCH 1/3] iommu/vt-d: skip RMRR entries that fail the sanity check Barret Rhoden
2019-12-11 19:46   ` Barret Rhoden via iommu
2019-12-16 19:07   ` Chen, Yian
2019-12-16 19:07     ` Chen, Yian
2019-12-16 19:35     ` Barret Rhoden
2019-12-16 19:35       ` Barret Rhoden via iommu
2019-12-17 19:19       ` Chen, Yian
2019-12-17 19:19         ` Chen, Yian
2019-12-23 20:27         ` Barret Rhoden
2019-12-23 20:27           ` Barret Rhoden via iommu
2019-12-11 19:46 ` Barret Rhoden [this message]
2019-12-11 19:46   ` [PATCH 2/3] iommu/vt-d: treat unmapped RMRR entries as sane Barret Rhoden via iommu
2019-12-11 19:46 ` [PATCH 3/3] iommu/vt-d: skip invalid RMRR entries Barret Rhoden
2019-12-11 19:46   ` Barret Rhoden via iommu
2019-12-12  2:43 ` [PATCH 0/3] iommu/vt-d bad RMRR workarounds Lu Baolu
2019-12-12  2:43   ` Lu Baolu
2019-12-13 14:31   ` Barret Rhoden
2019-12-13 14:31     ` Barret Rhoden via iommu
2019-12-14  1:52     ` Lu Baolu
2019-12-14  1:52       ` Lu Baolu
2019-12-16 19:11       ` Chen, Yian
2019-12-16 19:11         ` Chen, Yian

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