Re: [meta-virtualization][honister][PATCH 3/3] xen: fix boot on the Raspberry Pi 4 with Xen 4.14

[Bertrand Marquis <Bertrand.Marquis@arm.com>]

Hi Christopher,

> On 21 May 2022, at 20:04, Christopher Clark <christopher.w.clark@gmail.com> wrote:
>
> Apply the patch from Xen to fix device tree parsing in newer kernels.
>
> Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>

Cheers
Bertrand

> ---
> ...issing-device_type-property-in-pci-p.patch | 91 +++++++++++++++++++
> recipes-extended/xen/xen_4.14.bb              |  1 +
> 2 files changed, 92 insertions(+)
> create mode 100644 recipes-extended/xen/files/0001-xen-workaround-missing-device_type-property-in-pci-p.patch
>
> diff --git a/recipes-extended/xen/files/0001-xen-workaround-missing-device_type-property-in-pci-p.patch b/recipes-extended/xen/files/0001-xen-workaround-missing-device_type-property-in-pci-p.patch
> new file mode 100644
> index 0000000..09a461b
> --- /dev/null
> +++ b/recipes-extended/xen/files/0001-xen-workaround-missing-device_type-property-in-pci-p.patch
> @@ -0,0 +1,91 @@
> +From 5a4087004d1adbbb223925f3306db0e5824a2bdc Mon Sep 17 00:00:00 2001
> +From: Stefano Stabellini <sstabellini@kernel.org>
> +Date: Tue, 9 Feb 2021 11:53:34 -0800
> +Subject: [PATCH] xen: workaround missing device_type property in pci/pcie
> + nodes
> +
> +PCI buses differ from default buses in a few important ways, so it is
> +important to detect them properly. Normally, PCI buses are expected to
> +have the following property:
> +
> +    device_type = "pci"
> +
> +In reality, it is not always the case. To handle PCI bus nodes that
> +don't have the device_type property, also consider the node name: if the
> +node name is "pcie" or "pci" then consider the bus as a PCI bus.
> +
> +This commit is based on the Linux kernel commit
> +d1ac0002dd29 "of: address: Work around missing device_type property in
> +pcie nodes".
> +
> +This fixes Xen boot on RPi4. Some RPi4 kernels have the following node
> +on their device trees:
> +
> +&pcie0 {
> +     pci@1,0 {
> +             #address-cells = <3>;
> +             #size-cells = <2>;
> +             ranges;
> +
> +             reg = <0 0 0 0 0>;
> +
> +             usb@1,0 {
> +                     reg = <0x10000 0 0 0 0>;
> +                     resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
> +             };
> +     };
> +};
> +
> +The pci@1,0 node is a PCI bus. If we parse the node and its children as
> +a default bus, the reg property under usb@1,0 would have to be
> +interpreted as an address range mappable by the CPU, which is not the
> +case and would break.
> +
> +Link: https://lore.kernel.org/xen-devel/YBmQQ3Tzu++AadKx@mattapan.m5p.com/
> +[fix style on commit]
> +Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
> +Tested-by: Elliott Mitchell <ehem+xen@m5p.com>
> +Tested-by: Jukka Kaartinen <jukka.kaartinen@unikie.com>
> +Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
> +Acked-by: Julien Grall <jgrall@amazon.com>
> +---
> + xen/common/device_tree.c | 16 +++++++++++++++-
> + 1 file changed, 15 insertions(+), 1 deletion(-)
> +
> +diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
> +index 18825e333e..03d25a81ce 100644
> +--- a/xen/common/device_tree.c
> ++++ b/xen/common/device_tree.c
> +@@ -563,14 +563,28 @@ static unsigned int dt_bus_default_get_flags(const __be32 *addr)
> +  * PCI bus specific translator
> +  */
> +
> ++static bool dt_node_is_pci(const struct dt_device_node *np)
> ++{
> ++    bool is_pci = !strcmp(np->name, "pcie") || !strcmp(np->name, "pci");
> ++
> ++    if ( is_pci )
> ++        printk(XENLOG_WARNING "%s: Missing device_type\n", np->full_name);
> ++
> ++    return is_pci;
> ++}
> ++
> + static bool_t dt_bus_pci_match(const struct dt_device_node *np)
> + {
> +     /*
> +      * "pciex" is PCI Express "vci" is for the /chaos bridge on 1st-gen PCI
> +      * powermacs "ht" is hypertransport
> ++     *
> ++     * If none of the device_type match, and that the node name is
> ++     * "pcie" or "pci", accept the device as PCI (with a warning).
> +      */
> +     return !strcmp(np->type, "pci") || !strcmp(np->type, "pciex") ||
> +-        !strcmp(np->type, "vci") || !strcmp(np->type, "ht");
> ++        !strcmp(np->type, "vci") || !strcmp(np->type, "ht") ||
> ++        dt_node_is_pci(np);
> + }
> +
> + static void dt_bus_pci_count_cells(const struct dt_device_node *np,
> +--
> +2.25.1
> +
> diff --git a/recipes-extended/xen/xen_4.14.bb b/recipes-extended/xen/xen_4.14.bb
> index 267db16..c0fa938 100644
> --- a/recipes-extended/xen/xen_4.14.bb
> +++ b/recipes-extended/xen/xen_4.14.bb
> @@ -7,6 +7,7 @@ XEN_BRANCH ?= "stable-${XEN_REL}"
> SRC_URI = " \
>    git://xenbits.xen.org/xen.git;branch=${XEN_BRANCH} \
>    file://0001-menuconfig-mconf-cfg-Allow-specification-of-ncurses-location.patch \
> +    file://0001-xen-workaround-missing-device_type-property-in-pci-p.patch \
>    "
>
> LIC_FILES_CHKSUM ?= "file://COPYING;md5=419739e325a50f3d7b4501338e44a4e5"
> --
> 2.25.1
>

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