| Message ID | e440e4f16a506ecc87078635dbb3fda2ebd45346.1644341635.git.oleksii_moisieiev@epam.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce SCI-mediator feature | expand |
Hi Oleksii, On 08/02/2022 18:00, Oleksii Moisieiev wrote: > If enabled, host device-tree will be exported to hypfs and can be > accessed through /devicetree path. > Exported device-tree has the same format, as the device-tree > exported to the sysfs by the Linux kernel. > This is useful when XEN toolstack needs an access to the host device-tree. > > Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com> > --- > xen/arch/arm/Kconfig | 8 + > xen/arch/arm/Makefile | 1 + > xen/arch/arm/host_dtb_export.c | 307 +++++++++++++++++++++++++++++++++ There is nothing specific in this file. So can this be moved in common/? > 3 files changed, 316 insertions(+) > create mode 100644 xen/arch/arm/host_dtb_export.c > > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig > index ecfa6822e4..895016b21e 100644 > --- a/xen/arch/arm/Kconfig > +++ b/xen/arch/arm/Kconfig > @@ -33,6 +33,14 @@ config ACPI > Advanced Configuration and Power Interface (ACPI) support for Xen is > an alternative to device tree on ARM64. > > +config HOST_DTB_EXPORT > + bool "Export host device tree to hypfs if enabled" > + depends on ARM && HYPFS && !ACPI A Xen built with ACPI enabled will still be able to boot on a host using Device-Tree. So I don't think should depend on ACPI. Also, I think this should depend on HAS_DEVICE_TREE rather than ARM. > + ---help--- > + > + Export host device-tree to hypfs so toolstack can have an access for the > + host device tree from Dom0. If you unsure say N. > + > config GICV3 > bool "GICv3 driver" > depends on ARM_64 && !NEW_VGIC > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile > index 07f634508e..0a41f68f8c 100644 > --- a/xen/arch/arm/Makefile > +++ b/xen/arch/arm/Makefile > @@ -8,6 +8,7 @@ obj-y += platforms/ > endif > obj-$(CONFIG_TEE) += tee/ > obj-$(CONFIG_HAS_VPCI) += vpci.o > +obj-$(CONFIG_HOST_DTB_EXPORT) += host_dtb_export.o > > obj-$(CONFIG_HAS_ALTERNATIVE) += alternative.o > obj-y += bootfdt.init.o > diff --git a/xen/arch/arm/host_dtb_export.c b/xen/arch/arm/host_dtb_export.c > new file mode 100644 > index 0000000000..794395683c > --- /dev/null > +++ b/xen/arch/arm/host_dtb_export.c This is mostly hypfs related. So CCing Juergen for his input on the code. > @@ -0,0 +1,307 @@ > +/* > + * xen/arch/arm/host_dtb_export.c > + * > + * Export host device-tree to the hypfs so toolstack can access > + * host device-tree from Dom0 > + * > + * Oleksii Moisieiev <oleksii_moisieiev@epam.com> > + * Copyright (C) 2021, EPAM Systems. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <xen/device_tree.h> > +#include <xen/err.h> > +#include <xen/guest_access.h> > +#include <xen/hypfs.h> > +#include <xen/init.h> > + > +#define HOST_DT_DIR "devicetree" > + > +static int host_dt_dir_read(const struct hypfs_entry *entry, > + XEN_GUEST_HANDLE_PARAM(void) uaddr); > +static unsigned int host_dt_dir_getsize(const struct hypfs_entry *entry); > + > +static const struct hypfs_entry *host_dt_dir_enter( > + const struct hypfs_entry *entry); > +static void host_dt_dir_exit(const struct hypfs_entry *entry); > + > +static struct hypfs_entry *host_dt_dir_findentry( > + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len); This is new code. So can you please make sure to avoid forward declaration by re-ordering the code. [...] > +static char *get_root_from_path(const char *path, char *name) > +{ > + const char *nm = strchr(path, '/'); > + if ( !nm ) > + nm = path + strlen(path); > + else > + { > + if ( !*nm ) > + nm--; > + } > + > + return memcpy(name, path, nm - path); What does guaranteee that name will be big enough for the new value? > +} > + > +static int host_dt_dir_read(const struct hypfs_entry *entry, > + XEN_GUEST_HANDLE_PARAM(void) uaddr) > +{ > + int ret = 0; > + struct dt_device_node *node; > + struct dt_device_node *child; The hypfs should not modify the device-tree. So can this be const? > + const struct dt_property *prop; > + struct hypfs_dyndir_id *data; > + > + data = hypfs_get_dyndata(); > + if ( !data ) > + return -EINVAL; [...] > +static struct hypfs_entry *host_dt_dir_findentry( > + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len) > +{ > + struct dt_device_node *node; > + char root_name[HYPFS_DYNDIR_ID_NAMELEN]; > + struct dt_device_node *child; > + struct hypfs_dyndir_id *data; > + struct dt_property *prop; > + > + data = hypfs_get_dyndata(); > + if ( !data ) > + return ERR_PTR(-EINVAL); > + > + node = data->data; > + if ( !node ) > + return ERR_PTR(-EINVAL); > + > + memset(root_name, 0, sizeof(root_name)); > + get_root_from_path(name, root_name); > + > + for ( child = node->child; child != NULL; child = child->sibling ) > + { > + if ( strcmp(get_name_from_path(child->full_name), root_name) == 0 ) > + return hypfs_gen_dyndir_entry(&dt_dir.e, > + get_name_from_path(child->full_name), child); > + } > + > + dt_for_each_property_node( node, prop ) > + { > + > + if ( dt_property_name_is_equal(prop, root_name) ) > + return hypfs_gen_dyndir_entry(&dt_prop.e, prop->name, prop); > + } > + > + return ERR_PTR(-ENOENT); [...] > +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); > + > +static int __init host_dtb_export_init(void) > +{ > + ASSERT(dt_host && (dt_host->sibling == NULL)); dt_host can be NULL when booting on ACPI platform. So I think this wants to be turned to a normal check and return directly. Also could you explain why you need to check dt_host->sibling? Cheers,
Hi Julien, On Tue, Feb 08, 2022 at 06:26:54PM +0000, Julien Grall wrote: > Hi Oleksii, > > On 08/02/2022 18:00, Oleksii Moisieiev wrote: > > If enabled, host device-tree will be exported to hypfs and can be > > accessed through /devicetree path. > > Exported device-tree has the same format, as the device-tree > > exported to the sysfs by the Linux kernel. > > This is useful when XEN toolstack needs an access to the host device-tree. > > > > Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com> > > --- > > xen/arch/arm/Kconfig | 8 + > > xen/arch/arm/Makefile | 1 + > > xen/arch/arm/host_dtb_export.c | 307 +++++++++++++++++++++++++++++++++ > > There is nothing specific in this file. So can this be moved in common/? You're right. I will move it to common. > > > 3 files changed, 316 insertions(+) > > create mode 100644 xen/arch/arm/host_dtb_export.c > > > > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig > > index ecfa6822e4..895016b21e 100644 > > --- a/xen/arch/arm/Kconfig > > +++ b/xen/arch/arm/Kconfig > > @@ -33,6 +33,14 @@ config ACPI > > Advanced Configuration and Power Interface (ACPI) support for Xen is > > an alternative to device tree on ARM64. > > +config HOST_DTB_EXPORT > > + bool "Export host device tree to hypfs if enabled" > > + depends on ARM && HYPFS && !ACPI > > A Xen built with ACPI enabled will still be able to boot on a host using > Device-Tree. So I don't think should depend on ACPI. > > Also, I think this should depend on HAS_DEVICE_TREE rather than ARM. I agree. Thank you. > > > + ---help--- > > + > > + Export host device-tree to hypfs so toolstack can have an access for the > > + host device tree from Dom0. If you unsure say N. > > + > > config GICV3 > > bool "GICv3 driver" > > depends on ARM_64 && !NEW_VGIC > > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile > > index 07f634508e..0a41f68f8c 100644 > > --- a/xen/arch/arm/Makefile > > +++ b/xen/arch/arm/Makefile > > @@ -8,6 +8,7 @@ obj-y += platforms/ > > endif > > obj-$(CONFIG_TEE) += tee/ > > obj-$(CONFIG_HAS_VPCI) += vpci.o > > +obj-$(CONFIG_HOST_DTB_EXPORT) += host_dtb_export.o > > obj-$(CONFIG_HAS_ALTERNATIVE) += alternative.o > > obj-y += bootfdt.init.o > > diff --git a/xen/arch/arm/host_dtb_export.c b/xen/arch/arm/host_dtb_export.c > > new file mode 100644 > > index 0000000000..794395683c > > --- /dev/null > > +++ b/xen/arch/arm/host_dtb_export.c > > This is mostly hypfs related. So CCing Juergen for his input on the code. Thank you. > > > @@ -0,0 +1,307 @@ > > +/* > > + * xen/arch/arm/host_dtb_export.c > > + * > > + * Export host device-tree to the hypfs so toolstack can access > > + * host device-tree from Dom0 > > + * > > + * Oleksii Moisieiev <oleksii_moisieiev@epam.com> > > + * Copyright (C) 2021, EPAM Systems. > > + * > > + * This program is free software; you can redistribute it and/or modify > > + * it under the terms of the GNU General Public License as published by > > + * the Free Software Foundation; either version 2 of the License, or > > + * (at your option) any later version. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + */ > > + > > +#include <xen/device_tree.h> > > +#include <xen/err.h> > > +#include <xen/guest_access.h> > > +#include <xen/hypfs.h> > > +#include <xen/init.h> > > + > > +#define HOST_DT_DIR "devicetree" > > + > > +static int host_dt_dir_read(const struct hypfs_entry *entry, > > + XEN_GUEST_HANDLE_PARAM(void) uaddr); > > +static unsigned int host_dt_dir_getsize(const struct hypfs_entry *entry); > > + > > +static const struct hypfs_entry *host_dt_dir_enter( > > + const struct hypfs_entry *entry); > > +static void host_dt_dir_exit(const struct hypfs_entry *entry); > > + > > +static struct hypfs_entry *host_dt_dir_findentry( > > + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len); > > This is new code. So can you please make sure to avoid forward declaration > by re-ordering the code. > I can't avoid forward declaration here because all those functions should be passed as callbacks for node template dt_dir. And dt_dir is used in read and findentry functions. > > [...] > > > +static char *get_root_from_path(const char *path, char *name) > > +{ > > + const char *nm = strchr(path, '/'); > > + if ( !nm ) > > + nm = path + strlen(path); > > + else > > + { > > + if ( !*nm ) > > + nm--; > > + } > > + > > + return memcpy(name, path, nm - path); > > What does guaranteee that name will be big enough for the new value? I will refactor that. > > > +} > > + > > +static int host_dt_dir_read(const struct hypfs_entry *entry, > > + XEN_GUEST_HANDLE_PARAM(void) uaddr) > > +{ > > + int ret = 0; > > + struct dt_device_node *node; > > + struct dt_device_node *child; > > The hypfs should not modify the device-tree. So can this be const? That's a good point. Unfortunatelly child can't be const because it is going to be passed to data->data pointer, but node can be const I think. In any case I will go through the file and see where const for the device_node can be set. > > > + const struct dt_property *prop; > > + struct hypfs_dyndir_id *data; > > + > > + data = hypfs_get_dyndata(); > > + if ( !data ) > > + return -EINVAL; > > [...] > > > +static struct hypfs_entry *host_dt_dir_findentry( > > + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len) > > +{ > > + struct dt_device_node *node; > > + char root_name[HYPFS_DYNDIR_ID_NAMELEN]; > > + struct dt_device_node *child; > > + struct hypfs_dyndir_id *data; > > + struct dt_property *prop; > > + > > + data = hypfs_get_dyndata(); > > + if ( !data ) > > + return ERR_PTR(-EINVAL); > > + > > + node = data->data; > > + if ( !node ) > > + return ERR_PTR(-EINVAL); > > + > > + memset(root_name, 0, sizeof(root_name)); > > + get_root_from_path(name, root_name); > > + > > + for ( child = node->child; child != NULL; child = child->sibling ) > > + { > > + if ( strcmp(get_name_from_path(child->full_name), root_name) == 0 ) > > + return hypfs_gen_dyndir_entry(&dt_dir.e, > > + get_name_from_path(child->full_name), child); > > + } > > + > > + dt_for_each_property_node( node, prop ) > > + { > > + > > + if ( dt_property_name_is_equal(prop, root_name) ) > > + return hypfs_gen_dyndir_entry(&dt_prop.e, prop->name, prop); > > + } > > + > > + return ERR_PTR(-ENOENT); > > [...] > > > +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); > > + > > +static int __init host_dtb_export_init(void) > > +{ > > + ASSERT(dt_host && (dt_host->sibling == NULL)); > > dt_host can be NULL when booting on ACPI platform. So I think this wants to > be turned to a normal check and return directly. > I will replace if with if ( !acpi_disabled ) return -ENODEV; > Also could you explain why you need to check dt_host->sibling? > This is my way to check if dt_host points to the top of the device-tree. In any case I will replace it with !acpi_disabled as I mentioned earlier. Best regards, Oleksii
On 09/02/2022 10:20, Oleksii Moisieiev wrote: > Hi Julien, Hi, > > On Tue, Feb 08, 2022 at 06:26:54PM +0000, Julien Grall wrote: >> Hi Oleksii, >> >> On 08/02/2022 18:00, Oleksii Moisieiev wrote: >>> If enabled, host device-tree will be exported to hypfs and can be >>> accessed through /devicetree path. >>> Exported device-tree has the same format, as the device-tree >>> exported to the sysfs by the Linux kernel. >>> This is useful when XEN toolstack needs an access to the host device-tree. >>> >>> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com> >>> --- >>> xen/arch/arm/Kconfig | 8 + >>> xen/arch/arm/Makefile | 1 + >>> xen/arch/arm/host_dtb_export.c | 307 +++++++++++++++++++++++++++++++++ >> >> There is nothing specific in this file. So can this be moved in common/? > > You're right. I will move it to common. > >> >>> 3 files changed, 316 insertions(+) >>> create mode 100644 xen/arch/arm/host_dtb_export.c >>> >>> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig >>> index ecfa6822e4..895016b21e 100644 >>> --- a/xen/arch/arm/Kconfig >>> +++ b/xen/arch/arm/Kconfig >>> @@ -33,6 +33,14 @@ config ACPI >>> Advanced Configuration and Power Interface (ACPI) support for Xen is >>> an alternative to device tree on ARM64. >>> +config HOST_DTB_EXPORT >>> + bool "Export host device tree to hypfs if enabled" >>> + depends on ARM && HYPFS && !ACPI >> >> A Xen built with ACPI enabled will still be able to boot on a host using >> Device-Tree. So I don't think should depend on ACPI. >> >> Also, I think this should depend on HAS_DEVICE_TREE rather than ARM. > > I agree. Thank you. > >> >>> + ---help--- >>> + >>> + Export host device-tree to hypfs so toolstack can have an access for the >>> + host device tree from Dom0. If you unsure say N. >>> + >>> config GICV3 >>> bool "GICv3 driver" >>> depends on ARM_64 && !NEW_VGIC >>> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile >>> index 07f634508e..0a41f68f8c 100644 >>> --- a/xen/arch/arm/Makefile >>> +++ b/xen/arch/arm/Makefile >>> @@ -8,6 +8,7 @@ obj-y += platforms/ >>> endif >>> obj-$(CONFIG_TEE) += tee/ >>> obj-$(CONFIG_HAS_VPCI) += vpci.o >>> +obj-$(CONFIG_HOST_DTB_EXPORT) += host_dtb_export.o >>> obj-$(CONFIG_HAS_ALTERNATIVE) += alternative.o >>> obj-y += bootfdt.init.o >>> diff --git a/xen/arch/arm/host_dtb_export.c b/xen/arch/arm/host_dtb_export.c >>> new file mode 100644 >>> index 0000000000..794395683c >>> --- /dev/null >>> +++ b/xen/arch/arm/host_dtb_export.c >> >> This is mostly hypfs related. So CCing Juergen for his input on the code. > > Thank you. > >> >>> @@ -0,0 +1,307 @@ >>> +/* >>> + * xen/arch/arm/host_dtb_export.c >>> + * >>> + * Export host device-tree to the hypfs so toolstack can access >>> + * host device-tree from Dom0 >>> + * >>> + * Oleksii Moisieiev <oleksii_moisieiev@epam.com> >>> + * Copyright (C) 2021, EPAM Systems. >>> + * >>> + * This program is free software; you can redistribute it and/or modify >>> + * it under the terms of the GNU General Public License as published by >>> + * the Free Software Foundation; either version 2 of the License, or >>> + * (at your option) any later version. >>> + * >>> + * This program is distributed in the hope that it will be useful, >>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >>> + * GNU General Public License for more details. >>> + */ >>> + >>> +#include <xen/device_tree.h> >>> +#include <xen/err.h> >>> +#include <xen/guest_access.h> >>> +#include <xen/hypfs.h> >>> +#include <xen/init.h> >>> + >>> +#define HOST_DT_DIR "devicetree" >>> + >>> +static int host_dt_dir_read(const struct hypfs_entry *entry, >>> + XEN_GUEST_HANDLE_PARAM(void) uaddr); >>> +static unsigned int host_dt_dir_getsize(const struct hypfs_entry *entry); >>> + >>> +static const struct hypfs_entry *host_dt_dir_enter( >>> + const struct hypfs_entry *entry); >>> +static void host_dt_dir_exit(const struct hypfs_entry *entry); >>> + >>> +static struct hypfs_entry *host_dt_dir_findentry( >>> + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len); >> >> This is new code. So can you please make sure to avoid forward declaration >> by re-ordering the code. >> > > I can't avoid forward declaration here because all those functions > should be passed as callbacks for node template dt_dir. And dt_dir is > used in read and findentry functions. You can avoid most of those forward declarations if you define the static variable now but fill them up after (see [1]). I don't think we can avoid the static variable forward declaration without reworking the API. BTW, I could not fully apply the series on the staging tree: Applying: xen/hypfs: support fo nested dynamic hypfs nodes Applying: libs: libxenhypfs - handle blob properties Applying: xen/arm: Export host device-tree to hypfs Applying: xen/arm: add generic SCI mediator framework error: patch failed: MAINTAINERS:512 error: MAINTAINERS: patch does not apply error: patch failed: xen/arch/arm/domain_build.c:1894 error: xen/arch/arm/domain_build.c: patch does not apply error: xen/include/asm-arm/domain.h: does not exist in index Patch failed at 0004 xen/arm: add generic SCI mediator framework hint: Use 'git am --show-current-patch=diff' to see the failed patch When you have resolved this problem, run "git am --continue". If you prefer to skip this patch, run "git am --skip" instead. To restore the original branch and stop patching, run "git am --abort". From the errors, it sounds like your baseline is from a couple of months ago. Please make sure to send your series based on the latest staging (at the time you send it). >>> +static int host_dt_dir_read(const struct hypfs_entry *entry, >>> + XEN_GUEST_HANDLE_PARAM(void) uaddr) >>> +{ >>> + int ret = 0; >>> + struct dt_device_node *node; >>> + struct dt_device_node *child; >> >> The hypfs should not modify the device-tree. So can this be const? > > That's a good point. > Unfortunatelly child can't be const because it is going to be passed to > data->data pointer, but node can be const I think. In any case I will go > through the file and see where const for the device_node can be set. Can you explain why that data->data is not const? >>> +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); >>> + >>> +static int __init host_dtb_export_init(void) >>> +{ >>> + ASSERT(dt_host && (dt_host->sibling == NULL)); >> >> dt_host can be NULL when booting on ACPI platform. So I think this wants to >> be turned to a normal check and return directly. >> > > I will replace if with > if ( !acpi_disabled ) > return -ENODEV; > >> Also could you explain why you need to check dt_host->sibling? >> > > This is my way to check if dt_host points to the top of the device-tree. > In any case I will replace it with !acpi_disabled as I mentioned > earlier. dt_host will always points to the root of the host device-tree. I don't think it is the job of hypfs to enforce it unless you expect the code to be buggy if this happens. But then I would argue the code should be hardened. Cheers, [1] diff --git a/xen/arch/arm/host_dtb_export.c b/xen/arch/arm/host_dtb_export.c index 794395683cd1..5f242b2cb683 100644 --- a/xen/arch/arm/host_dtb_export.c +++ b/xen/arch/arm/host_dtb_export.c @@ -26,39 +26,9 @@ #define HOST_DT_DIR "devicetree" -static int host_dt_dir_read(const struct hypfs_entry *entry, - XEN_GUEST_HANDLE_PARAM(void) uaddr); -static unsigned int host_dt_dir_getsize(const struct hypfs_entry *entry); - -static const struct hypfs_entry *host_dt_dir_enter( - const struct hypfs_entry *entry); -static void host_dt_dir_exit(const struct hypfs_entry *entry); - -static struct hypfs_entry *host_dt_dir_findentry( - const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len); - -static const struct hypfs_funcs host_dt_dir_funcs = { - .enter = host_dt_dir_enter, - .exit = host_dt_dir_exit, - .read = host_dt_dir_read, - .write = hypfs_write_deny, - .getsize = host_dt_dir_getsize, - .findentry = host_dt_dir_findentry, -}; - -static int host_dt_prop_read(const struct hypfs_entry *entry, - XEN_GUEST_HANDLE_PARAM(void) uaddr); - -static unsigned int host_dt_prop_getsize(const struct hypfs_entry *entry); - -const struct hypfs_funcs host_dt_prop_ro_funcs = { - .enter = host_dt_dir_enter, - .exit = host_dt_dir_exit, - .read = host_dt_prop_read, - .write = hypfs_write_deny, - .getsize = host_dt_prop_getsize, - .findentry = hypfs_leaf_findentry, -}; +/* Forward declare it */ +static const struct hypfs_funcs host_dt_dir_funcs; +static const struct hypfs_funcs host_dt_prop_ro_funcs; static HYPFS_DIR_INIT_FUNC(dt_dir, "node_template", &host_dt_dir_funcs); @@ -260,6 +230,15 @@ static struct hypfs_entry *host_dt_dir_findentry( return ERR_PTR(-ENOENT); }; +static const struct hypfs_funcs host_dt_dir_funcs = { + .enter = host_dt_dir_enter, + .exit = host_dt_dir_exit, + .read = host_dt_dir_read, + .write = hypfs_write_deny, + .getsize = host_dt_dir_getsize, + .findentry = host_dt_dir_findentry, +}; + static int host_dt_prop_read(const struct hypfs_entry *entry, XEN_GUEST_HANDLE_PARAM(void) uaddr) { @@ -293,6 +272,15 @@ static unsigned int host_dt_prop_getsize(const struct hypfs_entry *entry) return prop->length; } +static const struct hypfs_funcs host_dt_prop_ro_funcs = { + .enter = host_dt_dir_enter, + .exit = host_dt_dir_exit, + .read = host_dt_prop_read, + .write = hypfs_write_deny, + .getsize = host_dt_prop_getsize, + .findentry = hypfs_leaf_findentry, +}; + static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); static int __init host_dtb_export_init(void)
On 08.02.22 19:26, Julien Grall wrote: > Hi Oleksii, > > On 08/02/2022 18:00, Oleksii Moisieiev wrote: >> If enabled, host device-tree will be exported to hypfs and can be >> accessed through /devicetree path. >> Exported device-tree has the same format, as the device-tree >> exported to the sysfs by the Linux kernel. >> This is useful when XEN toolstack needs an access to the host >> device-tree. >> >> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com> >> --- >> xen/arch/arm/Kconfig | 8 + >> xen/arch/arm/Makefile | 1 + >> xen/arch/arm/host_dtb_export.c | 307 +++++++++++++++++++++++++++++++++ The related doc changes in docs/misc/hypfs-paths.pandoc are missing. Without those its rather hard to verify the code is correct. Juergen
Hi Julien, On Wed, Feb 09, 2022 at 12:17:17PM +0000, Julien Grall wrote: > > > On 09/02/2022 10:20, Oleksii Moisieiev wrote: > > Hi Julien, > > Hi, > > > > > On Tue, Feb 08, 2022 at 06:26:54PM +0000, Julien Grall wrote: > > > Hi Oleksii, > > > > > > On 08/02/2022 18:00, Oleksii Moisieiev wrote: > > > > If enabled, host device-tree will be exported to hypfs and can be > > > > accessed through /devicetree path. > > > > Exported device-tree has the same format, as the device-tree > > > > exported to the sysfs by the Linux kernel. > > > > This is useful when XEN toolstack needs an access to the host device-tree. > > > > > > > > Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com> > > > > --- > > > > xen/arch/arm/Kconfig | 8 + > > > > xen/arch/arm/Makefile | 1 + > > > > xen/arch/arm/host_dtb_export.c | 307 +++++++++++++++++++++++++++++++++ > > > > > > There is nothing specific in this file. So can this be moved in common/? > > > > You're right. I will move it to common. > > > > > > > > > 3 files changed, 316 insertions(+) > > > > create mode 100644 xen/arch/arm/host_dtb_export.c > > > > > > > > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig > > > > index ecfa6822e4..895016b21e 100644 > > > > --- a/xen/arch/arm/Kconfig > > > > +++ b/xen/arch/arm/Kconfig > > > > @@ -33,6 +33,14 @@ config ACPI > > > > Advanced Configuration and Power Interface (ACPI) support for Xen is > > > > an alternative to device tree on ARM64. > > > > +config HOST_DTB_EXPORT > > > > + bool "Export host device tree to hypfs if enabled" > > > > + depends on ARM && HYPFS && !ACPI > > > > > > A Xen built with ACPI enabled will still be able to boot on a host using > > > Device-Tree. So I don't think should depend on ACPI. > > > > > > Also, I think this should depend on HAS_DEVICE_TREE rather than ARM. > > > > I agree. Thank you. > > > > > > > > > + ---help--- > > > > + > > > > + Export host device-tree to hypfs so toolstack can have an access for the > > > > + host device tree from Dom0. If you unsure say N. > > > > + > > > > config GICV3 > > > > bool "GICv3 driver" > > > > depends on ARM_64 && !NEW_VGIC > > > > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile > > > > index 07f634508e..0a41f68f8c 100644 > > > > --- a/xen/arch/arm/Makefile > > > > +++ b/xen/arch/arm/Makefile > > > > @@ -8,6 +8,7 @@ obj-y += platforms/ > > > > endif > > > > obj-$(CONFIG_TEE) += tee/ > > > > obj-$(CONFIG_HAS_VPCI) += vpci.o > > > > +obj-$(CONFIG_HOST_DTB_EXPORT) += host_dtb_export.o > > > > obj-$(CONFIG_HAS_ALTERNATIVE) += alternative.o > > > > obj-y += bootfdt.init.o > > > > diff --git a/xen/arch/arm/host_dtb_export.c b/xen/arch/arm/host_dtb_export.c > > > > new file mode 100644 > > > > index 0000000000..794395683c > > > > --- /dev/null > > > > +++ b/xen/arch/arm/host_dtb_export.c > > > > > > This is mostly hypfs related. So CCing Juergen for his input on the code. > > > > Thank you. > > > > > > > > > @@ -0,0 +1,307 @@ > > > > +/* > > > > + * xen/arch/arm/host_dtb_export.c > > > > + * > > > > + * Export host device-tree to the hypfs so toolstack can access > > > > + * host device-tree from Dom0 > > > > + * > > > > + * Oleksii Moisieiev <oleksii_moisieiev@epam.com> > > > > + * Copyright (C) 2021, EPAM Systems. > > > > + * > > > > + * This program is free software; you can redistribute it and/or modify > > > > + * it under the terms of the GNU General Public License as published by > > > > + * the Free Software Foundation; either version 2 of the License, or > > > > + * (at your option) any later version. > > > > + * > > > > + * This program is distributed in the hope that it will be useful, > > > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > > > + * GNU General Public License for more details. > > > > + */ > > > > + > > > > +#include <xen/device_tree.h> > > > > +#include <xen/err.h> > > > > +#include <xen/guest_access.h> > > > > +#include <xen/hypfs.h> > > > > +#include <xen/init.h> > > > > + > > > > +#define HOST_DT_DIR "devicetree" > > > > + > > > > +static int host_dt_dir_read(const struct hypfs_entry *entry, > > > > + XEN_GUEST_HANDLE_PARAM(void) uaddr); > > > > +static unsigned int host_dt_dir_getsize(const struct hypfs_entry *entry); > > > > + > > > > +static const struct hypfs_entry *host_dt_dir_enter( > > > > + const struct hypfs_entry *entry); > > > > +static void host_dt_dir_exit(const struct hypfs_entry *entry); > > > > + > > > > +static struct hypfs_entry *host_dt_dir_findentry( > > > > + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len); > > > > > > This is new code. So can you please make sure to avoid forward declaration > > > by re-ordering the code. > > > > > > > I can't avoid forward declaration here because all those functions > > should be passed as callbacks for node template dt_dir. And dt_dir is > > used in read and findentry functions. > > You can avoid most of those forward declarations if you define the static > variable now but fill them up after (see [1]). I don't think we can avoid > the static variable forward declaration without reworking the API. > > BTW, I could not fully apply the series on the staging tree: > > Applying: xen/hypfs: support fo nested dynamic hypfs nodes > Applying: libs: libxenhypfs - handle blob properties > Applying: xen/arm: Export host device-tree to hypfs > Applying: xen/arm: add generic SCI mediator framework > error: patch failed: MAINTAINERS:512 > error: MAINTAINERS: patch does not apply > error: patch failed: xen/arch/arm/domain_build.c:1894 > error: xen/arch/arm/domain_build.c: patch does not apply > error: xen/include/asm-arm/domain.h: does not exist in index > Patch failed at 0004 xen/arm: add generic SCI mediator framework > hint: Use 'git am --show-current-patch=diff' to see the failed patch > When you have resolved this problem, run "git am --continue". > If you prefer to skip this patch, run "git am --skip" instead. > To restore the original branch and stop patching, run "git am --abort". > > From the errors, it sounds like your baseline is from a couple of months > ago. Please make sure to send your series based on the latest staging (at > the time you send it). > I'm sorry for that. I will fix all comments, mentioned above, make a rebase and post v3 shortly. > > > > +static int host_dt_dir_read(const struct hypfs_entry *entry, > > > > + XEN_GUEST_HANDLE_PARAM(void) uaddr) > > > > +{ > > > > + int ret = 0; > > > > + struct dt_device_node *node; > > > > + struct dt_device_node *child; > > > > > > The hypfs should not modify the device-tree. So can this be const? > > > > That's a good point. > > Unfortunatelly child can't be const because it is going to be passed to > > data->data pointer, but node can be const I think. In any case I will go > > through the file and see where const for the device_node can be set. > > Can you explain why that data->data is not const? I reused struct hypfs_dyndir_id, added by @Juergen Gross in 4f1e5ed49c2292d3dd18160b7e728b1aa9453206 hope he will help to answer this question. > > > > +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); > > > > + > > > > +static int __init host_dtb_export_init(void) > > > > +{ > > > > + ASSERT(dt_host && (dt_host->sibling == NULL)); > > > > > > dt_host can be NULL when booting on ACPI platform. So I think this wants to > > > be turned to a normal check and return directly. > > > > > > > I will replace if with > > if ( !acpi_disabled ) > > return -ENODEV; > > > > > Also could you explain why you need to check dt_host->sibling? > > > > > > > This is my way to check if dt_host points to the top of the device-tree. > > In any case I will replace it with !acpi_disabled as I mentioned > > earlier. > > dt_host will always points to the root of the host device-tree. I don't > think it is the job of hypfs to enforce it unless you expect the code to be > buggy if this happens. But then I would argue the code should be hardened. > I will refactor this check. Best regards, Oleksii.
On Wed, Feb 09, 2022 at 12:17:17PM +0000, Julien Grall wrote: > > > > +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); > > > > + > > > > +static int __init host_dtb_export_init(void) > > > > +{ > > > > + ASSERT(dt_host && (dt_host->sibling == NULL)); > > > > > > dt_host can be NULL when booting on ACPI platform. So I think this wants to > > > be turned to a normal check and return directly. > > > > > > > I will replace if with > > if ( !acpi_disabled ) > > return -ENODEV; > > > > > Also could you explain why you need to check dt_host->sibling? > > > > > > > This is my way to check if dt_host points to the top of the device-tree. > > In any case I will replace it with !acpi_disabled as I mentioned > > earlier. > > dt_host will always points to the root of the host device-tree. I don't > think it is the job of hypfs to enforce it unless you expect the code to be > buggy if this happens. But then I would argue the code should be hardened. > Hi Julien, Unfortunatelly I can't use acpi_disabled in host_dtb_export_init because I've already moved host_dtb_export.c to the common folder. As for the host->sibling - I took the whole assert: ASSERT(dt_host && (dt_host->sibling == NULL)); from the prepare_dtb_hwdom function. And this assertion was added by the commit b8f1c5e7039efbe1103ed3fe4caedf8c34affe13 authored by you. What do you think if I omit dt_host->sibling check and make it: if ( !dt_host ) return -ENODEV; Best regards, Olkesii.
Hi, On 09/02/2022 18:51, Oleksii Moisieiev wrote: > On Wed, Feb 09, 2022 at 12:17:17PM +0000, Julien Grall wrote: >>>>> +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); >>>>> + >>>>> +static int __init host_dtb_export_init(void) >>>>> +{ >>>>> + ASSERT(dt_host && (dt_host->sibling == NULL)); >>>> >>>> dt_host can be NULL when booting on ACPI platform. So I think this wants to >>>> be turned to a normal check and return directly. >>>> >>> >>> I will replace if with >>> if ( !acpi_disabled ) >>> return -ENODEV; >>> >>>> Also could you explain why you need to check dt_host->sibling? >>>> >>> >>> This is my way to check if dt_host points to the top of the device-tree. >>> In any case I will replace it with !acpi_disabled as I mentioned >>> earlier. >> >> dt_host will always points to the root of the host device-tree. I don't >> think it is the job of hypfs to enforce it unless you expect the code to be >> buggy if this happens. But then I would argue the code should be hardened. >> > > Hi Julien, > > Unfortunatelly I can't use acpi_disabled in host_dtb_export_init because > I've already moved host_dtb_export.c to the common folder. I am sorry, but I don't understand why moving the code to common code prevents you to use !acpi_disabled. Can you clarify? > > As for the host->sibling - I took the whole assert: > ASSERT(dt_host && (dt_host->sibling == NULL)); > from the prepare_dtb_hwdom function. And this assertion was added by the > commit b8f1c5e7039efbe1103ed3fe4caedf8c34affe13 authored by you. I am not sure what's your point... Yes I wrote the same ASSERT() 9 years time. But people view evolves over the time. There are some code I wished I had written differently (How about you? ;)). However, I don't have the time to rewrite everything I ever wrote. That said, I can at least make sure they are not spread. > > What do you think if I omit dt_host->sibling check and make it: > > if ( !dt_host ) > return -ENODEV; We used to set dt_host even when booting with ACPI but that shouldn't be the case anymore. So I think this check should be fine. Cheers,
On Wed, Feb 09, 2022 at 07:34:57PM +0000, Julien Grall wrote: > Hi, > > On 09/02/2022 18:51, Oleksii Moisieiev wrote: > > On Wed, Feb 09, 2022 at 12:17:17PM +0000, Julien Grall wrote: > > > > > > +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); > > > > > > + > > > > > > +static int __init host_dtb_export_init(void) > > > > > > +{ > > > > > > + ASSERT(dt_host && (dt_host->sibling == NULL)); > > > > > > > > > > dt_host can be NULL when booting on ACPI platform. So I think this wants to > > > > > be turned to a normal check and return directly. > > > > > > > > > > > > > I will replace if with > > > > if ( !acpi_disabled ) > > > > return -ENODEV; > > > > > > > > > Also could you explain why you need to check dt_host->sibling? > > > > > > > > > > > > > This is my way to check if dt_host points to the top of the device-tree. > > > > In any case I will replace it with !acpi_disabled as I mentioned > > > > earlier. > > > > > > dt_host will always points to the root of the host device-tree. I don't > > > think it is the job of hypfs to enforce it unless you expect the code to be > > > buggy if this happens. But then I would argue the code should be hardened. > > > > > > > Hi Julien, > > > > Unfortunatelly I can't use acpi_disabled in host_dtb_export_init because > > I've already moved host_dtb_export.c to the common folder. > > I am sorry, but I don't understand why moving the code to common code > prevents you to use !acpi_disabled. Can you clarify? > Sorry, my bad. I thought that acpi_disabled is defined only for arm. Now I've rechecked and see I was wrong. > > > > As for the host->sibling - I took the whole assert: > > ASSERT(dt_host && (dt_host->sibling == NULL)); > > from the prepare_dtb_hwdom function. And this assertion was added by the > > commit b8f1c5e7039efbe1103ed3fe4caedf8c34affe13 authored by you. > > I am not sure what's your point... Yes I wrote the same ASSERT() 9 years > time. But people view evolves over the time. > > There are some code I wished I had written differently (How about you? ;)). > However, I don't have the time to rewrite everything I ever wrote. That > said, I can at least make sure they are not spread. > I'm sorry, I didn't mean to be rude. I've just tried to tell where I took this assertion from. > > > > What do you think if I omit dt_host->sibling check and make it: > > > > if ( !dt_host ) > > return -ENODEV; > > We used to set dt_host even when booting with ACPI but that shouldn't be the > case anymore. So I think this check should be fine. > Ok, thank you. I'll do the change. Best regards, Oleksii.
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig index ecfa6822e4..895016b21e 100644 --- a/xen/arch/arm/Kconfig +++ b/xen/arch/arm/Kconfig @@ -33,6 +33,14 @@ config ACPI Advanced Configuration and Power Interface (ACPI) support for Xen is an alternative to device tree on ARM64. +config HOST_DTB_EXPORT + bool "Export host device tree to hypfs if enabled" + depends on ARM && HYPFS && !ACPI + ---help--- + + Export host device-tree to hypfs so toolstack can have an access for the + host device tree from Dom0. If you unsure say N. + config GICV3 bool "GICv3 driver" depends on ARM_64 && !NEW_VGIC diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index 07f634508e..0a41f68f8c 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -8,6 +8,7 @@ obj-y += platforms/ endif obj-$(CONFIG_TEE) += tee/ obj-$(CONFIG_HAS_VPCI) += vpci.o +obj-$(CONFIG_HOST_DTB_EXPORT) += host_dtb_export.o obj-$(CONFIG_HAS_ALTERNATIVE) += alternative.o obj-y += bootfdt.init.o diff --git a/xen/arch/arm/host_dtb_export.c b/xen/arch/arm/host_dtb_export.c new file mode 100644 index 0000000000..794395683c --- /dev/null +++ b/xen/arch/arm/host_dtb_export.c @@ -0,0 +1,307 @@ +/* + * xen/arch/arm/host_dtb_export.c + * + * Export host device-tree to the hypfs so toolstack can access + * host device-tree from Dom0 + * + * Oleksii Moisieiev <oleksii_moisieiev@epam.com> + * Copyright (C) 2021, EPAM Systems. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <xen/device_tree.h> +#include <xen/err.h> +#include <xen/guest_access.h> +#include <xen/hypfs.h> +#include <xen/init.h> + +#define HOST_DT_DIR "devicetree" + +static int host_dt_dir_read(const struct hypfs_entry *entry, + XEN_GUEST_HANDLE_PARAM(void) uaddr); +static unsigned int host_dt_dir_getsize(const struct hypfs_entry *entry); + +static const struct hypfs_entry *host_dt_dir_enter( + const struct hypfs_entry *entry); +static void host_dt_dir_exit(const struct hypfs_entry *entry); + +static struct hypfs_entry *host_dt_dir_findentry( + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len); + +static const struct hypfs_funcs host_dt_dir_funcs = { + .enter = host_dt_dir_enter, + .exit = host_dt_dir_exit, + .read = host_dt_dir_read, + .write = hypfs_write_deny, + .getsize = host_dt_dir_getsize, + .findentry = host_dt_dir_findentry, +}; + +static int host_dt_prop_read(const struct hypfs_entry *entry, + XEN_GUEST_HANDLE_PARAM(void) uaddr); + +static unsigned int host_dt_prop_getsize(const struct hypfs_entry *entry); + +const struct hypfs_funcs host_dt_prop_ro_funcs = { + .enter = host_dt_dir_enter, + .exit = host_dt_dir_exit, + .read = host_dt_prop_read, + .write = hypfs_write_deny, + .getsize = host_dt_prop_getsize, + .findentry = hypfs_leaf_findentry, +}; + +static HYPFS_DIR_INIT_FUNC(dt_dir, "node_template", &host_dt_dir_funcs); + +#define HYPFS_PROPERTY_MAX_SIZE 256 +static HYPFS_VARSIZE_INIT(dt_prop, XEN_HYPFS_TYPE_BLOB, "prop_template", + HYPFS_PROPERTY_MAX_SIZE, &host_dt_prop_ro_funcs); + +static const char *get_name_from_path(const char *path) +{ + const char *name = strrchr(path, '/'); + if ( !name ) + name = path; + else + { + name++; + if ( !*name ) + name--; + } + + return name; +} + +static char *get_root_from_path(const char *path, char *name) +{ + const char *nm = strchr(path, '/'); + if ( !nm ) + nm = path + strlen(path); + else + { + if ( !*nm ) + nm--; + } + + return memcpy(name, path, nm - path); +} + +static int host_dt_dir_read(const struct hypfs_entry *entry, + XEN_GUEST_HANDLE_PARAM(void) uaddr) +{ + int ret = 0; + struct dt_device_node *node; + struct dt_device_node *child; + const struct dt_property *prop; + struct hypfs_dyndir_id *data; + + data = hypfs_get_dyndata(); + if ( !data ) + return -EINVAL; + + node = data->data; + if ( !node ) + return -EINVAL; + + dt_for_each_property_node( node, prop ) + { + ret = hypfs_read_dyndir_entry(&dt_prop.e, prop->name, + strlen(prop->name), + !prop->next && !node->child, + &uaddr); + + if ( ret ) + break; + } + + for ( child = node->child; child != NULL; child = child->sibling ) + { + const char *parsed_name = get_name_from_path(child->full_name); + data->data = child; + + ret = hypfs_read_dyndir_entry(&dt_dir.e, parsed_name, + strlen(parsed_name), + child->sibling == NULL, + &uaddr); + + if ( ret ) + break; + } + + return ret; +} + +static unsigned int host_dt_dir_getsize(const struct hypfs_entry *entry) +{ + struct dt_device_node *node; + struct dt_device_node *child; + struct hypfs_dyndir_id *data; + const struct dt_property *prop; + unsigned int size = 0; + + data = hypfs_get_dyndata(); + if ( !data ) + return -EINVAL; + + node = data->data; + if ( !node ) + return -EINVAL; + + dt_for_each_property_node( node, prop ) + { + size += hypfs_dyndir_entry_size(entry, prop->name); + } + + for ( child = node->child; child != NULL; child = child->sibling ) + { + const char *parsed_name = get_name_from_path(child->full_name); + size += hypfs_dyndir_entry_size(entry, parsed_name); + } + + return size; +} + +static DEFINE_PER_CPU(bool, data_alloc); + +static inline bool data_is_alloc(void) +{ + unsigned int cpu = smp_processor_id(); + return per_cpu(data_alloc, cpu); +} + +static inline void set_data_alloc(void) +{ + unsigned int cpu = smp_processor_id(); + ASSERT(!per_cpu(data_alloc, cpu)); + + this_cpu(data_alloc) = true; +} + +static inline void unset_data_alloc(void) +{ + this_cpu(data_alloc) = false; +} + +static const struct hypfs_entry *host_dt_dir_enter( + const struct hypfs_entry *entry) +{ + struct hypfs_dyndir_id *data; + + if ( !data_is_alloc() ) + { + data = hypfs_alloc_dyndata(struct hypfs_dyndir_id); + if ( !data ) + return ERR_PTR(-ENOMEM); + + set_data_alloc(); + } + + if ( strcmp(entry->name, HOST_DT_DIR) == 0 ) + { + data = hypfs_get_dyndata(); + data->data = dt_host; + } + + return entry; +} + +static void host_dt_dir_exit(const struct hypfs_entry *entry) +{ + if ( !data_is_alloc() ) + return; + + hypfs_free_dyndata(); + unset_data_alloc(); +} + +static struct hypfs_entry *host_dt_dir_findentry( + const struct hypfs_entry_dir *dir, const char *name, unsigned int name_len) +{ + struct dt_device_node *node; + char root_name[HYPFS_DYNDIR_ID_NAMELEN]; + struct dt_device_node *child; + struct hypfs_dyndir_id *data; + struct dt_property *prop; + + data = hypfs_get_dyndata(); + if ( !data ) + return ERR_PTR(-EINVAL); + + node = data->data; + if ( !node ) + return ERR_PTR(-EINVAL); + + memset(root_name, 0, sizeof(root_name)); + get_root_from_path(name, root_name); + + for ( child = node->child; child != NULL; child = child->sibling ) + { + if ( strcmp(get_name_from_path(child->full_name), root_name) == 0 ) + return hypfs_gen_dyndir_entry(&dt_dir.e, + get_name_from_path(child->full_name), child); + } + + dt_for_each_property_node( node, prop ) + { + + if ( dt_property_name_is_equal(prop, root_name) ) + return hypfs_gen_dyndir_entry(&dt_prop.e, prop->name, prop); + } + + return ERR_PTR(-ENOENT); +}; + +static int host_dt_prop_read(const struct hypfs_entry *entry, + XEN_GUEST_HANDLE_PARAM(void) uaddr) +{ + const struct dt_property *prop; + struct hypfs_dyndir_id *data; + + data = hypfs_get_dyndata(); + if ( !data ) + return -EINVAL; + + prop = data->data; + if ( !prop ) + return -EINVAL; + + return copy_to_guest(uaddr, prop->value, prop->length) ? -EFAULT : 0; +} + +static unsigned int host_dt_prop_getsize(const struct hypfs_entry *entry) +{ + const struct hypfs_dyndir_id *data; + const struct dt_property *prop; + + data = hypfs_get_dyndata(); + if ( !data ) + return -EINVAL; + + prop = data->data; + if ( !prop ) + return -EINVAL; + + return prop->length; +} + +static HYPFS_DIR_INIT_FUNC(host_dt_dir, HOST_DT_DIR, &host_dt_dir_funcs); + +static int __init host_dtb_export_init(void) +{ + ASSERT(dt_host && (dt_host->sibling == NULL)); + unset_data_alloc(); + + hypfs_add_dir(&hypfs_root, &host_dt_dir, true); + hypfs_add_dyndir(&hypfs_root, &dt_dir); + return 0; +} +__initcall(host_dtb_export_init);
If enabled, host device-tree will be exported to hypfs and can be accessed through /devicetree path. Exported device-tree has the same format, as the device-tree exported to the sysfs by the Linux kernel. This is useful when XEN toolstack needs an access to the host device-tree. Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com> --- xen/arch/arm/Kconfig | 8 + xen/arch/arm/Makefile | 1 + xen/arch/arm/host_dtb_export.c | 307 +++++++++++++++++++++++++++++++++ 3 files changed, 316 insertions(+) create mode 100644 xen/arch/arm/host_dtb_export.c