On Fri, 23 Oct 2020, Julien Grall wrote:
> From: Julien Grall <jgr...@amazon.com>
>
> Since commit 6e3e77120378 "xen/arm: setup: Relocate the Device-Tree
> later on in the boot", the device-tree will not be kept mapped when
> using ACPI.
>
> However, a few places are calling dt_unreserved_regions() which expects
> a valid DT. This will lead to a crash.
>
> As the DT should not be used for ACPI (other than for detecting the
> modules), a new function fw_unreserved_regions() is introduced.
>
> It will behave the same way on DT system. On ACPI system, it will
> unreserve the whole region.
>
> Take the opportunity to clarify that bootinfo.reserved_mem is only used
> when booting using Device-Tree.
>
> Signed-off-by: Julien Grall <jgr...@amazon.com>
Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
> ---
>
> Is there any region we should exclude on ACPI?
>
> Changes in v2:
> - Add a comment on top of bootinfo.reserved_mem.
> ---
> xen/arch/arm/kernel.c | 2 +-
> xen/arch/arm/setup.c | 22 +++++++++++++++++-----
> xen/include/asm-arm/setup.h | 3 ++-
> 3 files changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
> index 032923853f2c..ab78689ed2a6 100644
> --- a/xen/arch/arm/kernel.c
> +++ b/xen/arch/arm/kernel.c
> @@ -307,7 +307,7 @@ static __init int kernel_decompress(struct bootmodule
> *mod)
> * Free the original kernel, update the pointers to the
> * decompressed kernel
> */
> - dt_unreserved_regions(addr, addr + size, init_domheap_pages, 0);
> + fw_unreserved_regions(addr, addr + size, init_domheap_pages, 0);
>
> return 0;
> }
> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> index 35e5bee04efa..7fcff9af2a7e 100644
> --- a/xen/arch/arm/setup.c
> +++ b/xen/arch/arm/setup.c
> @@ -196,8 +196,9 @@ static void __init processor_id(void)
> processor_setup();
> }
>
> -void __init dt_unreserved_regions(paddr_t s, paddr_t e,
> - void (*cb)(paddr_t, paddr_t), int first)
> +static void __init dt_unreserved_regions(paddr_t s, paddr_t e,
> + void (*cb)(paddr_t, paddr_t),
> + int first)
> {
> int i, nr = fdt_num_mem_rsv(device_tree_flattened);
>
> @@ -244,6 +245,17 @@ void __init dt_unreserved_regions(paddr_t s, paddr_t e,
> cb(s, e);
> }
>
> +void __init fw_unreserved_regions(paddr_t s, paddr_t e,
> + void (*cb)(paddr_t, paddr_t), int first)
> +{
> + if ( acpi_disabled )
> + dt_unreserved_regions(s, e, cb, first);
> + else
> + cb(s, e);
> +}
> +
> +
> +
> struct bootmodule __init *add_boot_module(bootmodule_kind kind,
> paddr_t start, paddr_t size,
> bool domU)
> @@ -405,7 +417,7 @@ void __init discard_initial_modules(void)
> !mfn_valid(maddr_to_mfn(e)) )
> continue;
>
> - dt_unreserved_regions(s, e, init_domheap_pages, 0);
> + fw_unreserved_regions(s, e, init_domheap_pages, 0);
> }
>
> mi->nr_mods = 0;
> @@ -712,7 +724,7 @@ static void __init setup_mm(void)
> n = mfn_to_maddr(mfn_add(xenheap_mfn_start, xenheap_pages));
> }
>
> - dt_unreserved_regions(s, e, init_boot_pages, 0);
> + fw_unreserved_regions(s, e, init_boot_pages, 0);
>
> s = n;
> }
> @@ -765,7 +777,7 @@ static void __init setup_mm(void)
> if ( e > bank_end )
> e = bank_end;
>
> - dt_unreserved_regions(s, e, init_boot_pages, 0);
> + fw_unreserved_regions(s, e, init_boot_pages, 0);
> s = n;
> }
> }
> diff --git a/xen/include/asm-arm/setup.h b/xen/include/asm-arm/setup.h
> index 2f8f24e286ed..28bf622aa196 100644
> --- a/xen/include/asm-arm/setup.h
> +++ b/xen/include/asm-arm/setup.h
> @@ -67,6 +67,7 @@ struct bootcmdlines {
>
> struct bootinfo {
> struct meminfo mem;
> + /* The reserved regions are only used when booting using Device-Tree */
> struct meminfo reserved_mem;
> struct bootmodules modules;
> struct bootcmdlines cmdlines;
> @@ -96,7 +97,7 @@ int construct_dom0(struct domain *d);
> void create_domUs(void);
>
> void discard_initial_modules(void);
> -void dt_unreserved_regions(paddr_t s, paddr_t e,
> +void fw_unreserved_regions(paddr_t s, paddr_t e,
> void (*cb)(paddr_t, paddr_t), int first);
>
> size_t boot_fdt_info(const void *fdt, paddr_t paddr);
> --
> 2.17.1
>
