From: Penny Zheng <penny.zheng@arm.com>
To: <xen-devel@lists.xenproject.org>, <sstabellini@kernel.org>,
<julien@xen.org>
Cc: <Bertrand.Marquis@arm.com>, <Penny.Zheng@arm.com>, <Wei.Chen@arm.com>
Subject: [PATCH 11/11] xen/docs: add a document to explain how to do passthrough without IOMMU
Date: Thu, 23 Sep 2021 03:11:15 +0000 [thread overview]
Message-ID: <20210923031115.1429719-12-penny.zheng@arm.com> (raw)
In-Reply-To: <20210923031115.1429719-1-penny.zheng@arm.com>
From: Stefano Stabellini <stefano.stabellini@xilinx.com>
Make sure to start with a WARNING about security.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
---
docs/misc/arm/passthrough-noiommu.txt | 54 +++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
create mode 100644 docs/misc/arm/passthrough-noiommu.txt
diff --git a/docs/misc/arm/passthrough-noiommu.txt b/docs/misc/arm/passthrough-noiommu.txt
new file mode 100644
index 0000000000..61aeb8a5cd
--- /dev/null
+++ b/docs/misc/arm/passthrough-noiommu.txt
@@ -0,0 +1,54 @@
+Request Device Assignment without IOMMU support
+===============================================
+
+*WARNING:
+Users should be aware that it is not always secure to assign a device without
+IOMMU protection.
+When the device is not protected by the IOMMU, the administrator should make
+sure that:
+ 1. The device is assigned to a trusted guest.
+ 2. Users have additional security mechanism on the platform.
+
+
+This document assumes that the IOMMU is absent from the system or it is
+disabled (status = "disabled" in device tree).
+
+
+Add xen,force-assign-without-iommu; to the device tree snippet:
+
+ethernet: ethernet@ff0e0000 {
+ compatible = "cdns,zynqmp-gem";
+ xen,path = "/amba/ethernet@ff0e0000";
+ xen,reg = <0x0 0xff0e0000 0x1000 0x0 0xff0e0000>;
+ xen,force-assign-without-iommu;
+};
+
+Request 1:1 memory mapping for the domain on static allocation
+==============================================================
+
+Add a direct-map property under the appropriate /chosen/domU node which
+is also statically allocated with physical memory ranges through
+xen,static-mem property as its guest RAM.
+
+Below is an example on how to specify the 1:1 memory mapping for the domain
+on static allocation in the device-tree:
+
+/ {
+ chosen {
+ domU1 {
+ compatible = "xen,domain";
+ #address-cells = <0x2>;
+ #size-cells = <0x2>;
+ cpus = <2>;
+ memory = <0x0 0x80000>;
+ #xen,static-mem-address-cells = <0x1>;
+ #xen,static-mem-size-cells = <0x1>;
+ xen,static-mem = <0x30000000 0x20000000>;
+ direct-map;
+ ...
+ };
+ };
+};
+
+Besides reserving a 512MB region starting at the host physical address
+0x30000000 to DomU1, it also requests 1:1 memory mapping.
--
2.25.1
prev parent reply other threads:[~2021-09-23 3:17 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 3:11 [PATCH 00/11] 1:1 direct-map memory map Penny Zheng
2021-09-23 3:11 ` [PATCH 01/11] xen: reserve flags for internal usage in xen_domctl_createdomain Penny Zheng
2021-09-23 9:54 ` Julien Grall
2021-09-28 12:05 ` Jan Beulich
2021-10-11 10:45 ` Julien Grall
2021-10-11 11:13 ` Jan Beulich
2021-09-23 3:11 ` [PATCH 02/11] xen/arm: introduce XEN_DOMCTL_INTERNAL_directmap Penny Zheng
2021-09-23 10:00 ` Julien Grall
2021-09-23 3:11 ` [PATCH 03/11] xen/arm: introduce 1:1 direct-map for domUs Penny Zheng
2021-09-23 10:36 ` Julien Grall
2021-10-08 2:19 ` Penny Zheng
2021-09-23 3:11 ` [PATCH 04/11] xen/arm: introduce accessors for vgic dist, cpu, and rdist base addresses Penny Zheng
2021-09-23 10:45 ` Julien Grall
2021-09-23 3:11 ` [PATCH 05/11] xen/arm: vgic: introduce vgic.cbase Penny Zheng
2021-09-23 10:47 ` Julien Grall
2021-09-23 3:11 ` [PATCH 06/11] xen/arm: new vgic: update vgic_cpu_base Penny Zheng
2021-09-23 10:47 ` Julien Grall
2021-09-23 3:11 ` [PATCH 07/11] xen/arm: if 1:1 direct-map domain use native addresses for GICv2 Penny Zheng
2021-09-23 10:52 ` Julien Grall
2021-09-23 3:11 ` [PATCH 08/11] xen/arm: if 1:1 direct-map domain use native addresses for GICv3 Penny Zheng
2021-09-23 10:59 ` Julien Grall
2021-09-23 3:11 ` [PATCH 09/11] xen/arm: if 1:1 direct-map domain use native UART address and IRQ number for vPL011 Penny Zheng
2021-09-23 11:14 ` Julien Grall
2021-10-09 8:47 ` Penny Zheng
2021-10-11 10:49 ` Julien Grall
2021-10-12 2:42 ` Penny Zheng
2021-10-13 18:00 ` Julien Grall
2021-10-14 2:31 ` Penny Zheng
2021-09-23 3:11 ` [PATCH 10/11] xen/arm: device assignment on 1:1 direct-map domain Penny Zheng
2021-09-23 11:26 ` Julien Grall
2021-10-09 9:40 ` Penny Zheng
2021-10-11 11:14 ` Julien Grall
2021-10-12 2:29 ` Penny Zheng
2021-10-13 7:44 ` Penny Zheng
2021-10-13 7:51 ` Penny Zheng
2021-10-13 16:34 ` Julien Grall
2021-09-23 3:11 ` Penny Zheng [this message]
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