[Skiboot] [RFC PATCH v5 14/16] Add an ultravisor device tree in secure memory

[Alexey Kardashevskiy]

On 28/02/2020 07:40, Ryan Grimm wrote:
> This patch adds a UV FDT created in secure memory.  It is allocated
> directly after the ultravisor.
> 
> The UV FDT will contain information like the wrapping key.

Who is the consumer of this FDT?


> 
> The code uses libfdt directly to ensure only secure memory is used.
> 
> Signed-off-by: Ryan Grimm <grimm at linux.ibm.com>
> Signed-off-by: Ram Pai <linuxram at us.ibm.com>
> ---
>  hw/ultravisor.c      | 26 +++++++++++++++++++++++++-
>  include/ultravisor.h |  1 +
>  2 files changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ultravisor.c b/hw/ultravisor.c
> index 277faeeb..da5b8346 100644
> --- a/hw/ultravisor.c
> +++ b/hw/ultravisor.c
> @@ -12,6 +12,7 @@
>  #include <console.h>
>  #include <chip.h>
>  #include <libstb/container.h>
> +#include <libfdt/libfdt.h>
>  
>  static struct dt_node *uv_fw_node;
>  static uint64_t uv_base_addr;
> @@ -115,9 +116,27 @@ static int uv_decompress_image(void)
>  	return OPAL_SUCCESS;
>  }
>  
> +static int create_dtb_uv(void *uv_fdt)
> +{
> +	if (fdt_create(uv_fdt, UV_FDT_MAX_SIZE)) {
> +		prerror("UV: Failed to create uv_fdt\n");
> +		return OPAL_NO_MEM;
> +	}
> +
> +	fdt_finish_reservemap(uv_fdt);
> +	fdt_begin_node(uv_fdt, "");
> +	fdt_property_string(uv_fdt, "description", "Ultravisor fdt");
> +	fdt_begin_node(uv_fdt, "ibm,uv-fdt");
> +	fdt_property_string(uv_fdt, "compatible", "ibm,uv-fdt");
> +	fdt_end_node(uv_fdt);
> +	fdt_finish(uv_fdt);


Every one of these fdt_xxxx() can fail.


> +
> +	return OPAL_SUCCESS;
> +}
> +
>  void init_uv()
>  {
> -	uint64_t uv_dt_src, uv_fw_sz;
> +	uint64_t uv_dt_src, uv_fw_sz, uv_fdt_addr;
>  	struct dt_node *reserved_mem;
>  	int ret;
>  
> @@ -151,6 +170,11 @@ void init_uv()
>  
>  	dt_add_property_u64(uv_fw_node, "memcons", (u64)&uv_memcons);
>  	debug_descriptor.uv_memcons_phys = (u64)&uv_memcons;
> +
> +	uv_base_addr = dt_get_address(uv_fw_node, 0, NULL);
> +	uv_fdt_addr = uv_base_addr + UV_LOAD_MAX_SIZE;
> +	create_dtb_uv((void *)uv_fdt_addr);


create_dtb_uv() can fail but we ignore it? Thanks,


> +	dt_add_property_u64(uv_fw_node, "uv-fdt", uv_fdt_addr);
>  err:
>  	local_free(uv_image);
>  }
> diff --git a/include/ultravisor.h b/include/ultravisor.h
> index 26a986cd..347b085d 100644
> --- a/include/ultravisor.h
> +++ b/include/ultravisor.h
> @@ -14,6 +14,7 @@
>  #define UCALL_BUFSIZE 4
>  #define UV_READ_SCOM  0xF114
>  #define UV_WRITE_SCOM 0xF118
> +#define UV_FDT_MAX_SIZE		0x100000
>  
>  extern long ucall(unsigned long opcode, unsigned long *retbuf, ...);
>  extern int start_uv(uint64_t entry, void *fdt);
> 

-- 
Alexey