On Fri, Jun 16, 2017 at 01:52:32PM -0500, Tom Lendacky wrote:
> The boot data and command line data are present in memory in a decrypted
> state and are copied early in the boot process. The early page fault
> support will map these areas as encrypted, so before attempting to copy
> them, add decrypted mappings so the data is accessed properly when copied.
>
> For the initrd, encrypt this data in place. Since the future mapping of
> the initrd area will be mapped as encrypted the data will be accessed
> properly.
>
> Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
> ---
> arch/x86/include/asm/mem_encrypt.h | 6 +++
> arch/x86/include/asm/pgtable.h | 3 ++
> arch/x86/kernel/head64.c | 30 +++++++++++++--
> arch/x86/kernel/setup.c | 9 +++++
> arch/x86/mm/kasan_init_64.c | 2 +
> arch/x86/mm/mem_encrypt.c | 70
> ++++++++++++++++++++++++++++++++++++
> 6 files changed, 115 insertions(+), 5 deletions(-)
...
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index b7671b9..ea5e3a6 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -19,6 +19,8 @@
>
> #include <asm/tlbflush.h>
> #include <asm/fixmap.h>
> +#include <asm/setup.h>
> +#include <asm/bootparam.h>
>
> /*
> * Since SME related variables are set early in the boot process they must
> @@ -101,6 +103,74 @@ void __init sme_early_decrypt(resource_size_t paddr,
> unsigned long size)
> __sme_early_enc_dec(paddr, size, false);
> }
>
> +static void __init __sme_early_map_unmap_mem(void *vaddr, unsigned long size,
> + bool map)
> +{
> + unsigned long paddr = (unsigned long)vaddr - __PAGE_OFFSET;
> + pmdval_t pmd_flags, pmd;
> +
> + /* Use early_pmd_flags but remove the encryption mask */
> + pmd_flags = __sme_clr(early_pmd_flags);
> +
> + do {
> + pmd = map ? (paddr & PMD_MASK) + pmd_flags : 0;
> + __early_make_pgtable((unsigned long)vaddr, pmd);
> +
> + vaddr += PMD_SIZE;
> + paddr += PMD_SIZE;
> + size = (size <= PMD_SIZE) ? 0 : size - PMD_SIZE;
> + } while (size);
> +
> + write_cr3(__read_cr3());
local_flush_tlb() or __native_flush_tlb(). Probably the native variant
since this is early fun.
> +}
> +
> +static void __init __sme_map_unmap_bootdata(char *real_mode_data, bool map)
> +{
> + struct boot_params *boot_data;
> + unsigned long cmdline_paddr;
> +
> + /* If SME is not active, the bootdata is in the correct state */
> + if (!sme_active())
> + return;
> +
> + if (!map) {
> + /*
> + * If unmapping, get the command line address before
> + * unmapping the real_mode_data.
> + */
> + boot_data = (struct boot_params *)real_mode_data;
> + cmdline_paddr = boot_data->hdr.cmd_line_ptr |
> + ((u64)boot_data->ext_cmd_line_ptr << 32);
Let it stick out:
cmdline_paddr = bd->hdr.cmd_line_ptr | ((u64)bd->ext_cmd_line_ptr <<
32);
> + }
> +
> + __sme_early_map_unmap_mem(real_mode_data, sizeof(boot_params), map);
> +
> + if (map) {
> + /*
> + * If mapping, get the command line address after mapping
> + * the real_mode_data.
> + */
> + boot_data = (struct boot_params *)real_mode_data;
> + cmdline_paddr = boot_data->hdr.cmd_line_ptr |
> + ((u64)boot_data->ext_cmd_line_ptr << 32);
> + }
> +
> + if (!cmdline_paddr)
> + return;
> +
> + __sme_early_map_unmap_mem(__va(cmdline_paddr), COMMAND_LINE_SIZE, map);
Ok, so from looking at this function now - it does different things
depending on whether we map or not. So it doesn't look like a worker
function anymore and you can move the stuff back to the original callers
below. Should make the whole flow more readable.
> +}
> +
> +void __init sme_unmap_bootdata(char *real_mode_data)
> +{
> + __sme_map_unmap_bootdata(real_mode_data, false);
> +}
> +
> +void __init sme_map_bootdata(char *real_mode_data)
> +{
> + __sme_map_unmap_bootdata(real_mode_data, true);
> +}
> +
> void __init sme_early_init(void)
> {
> unsigned int i;
>
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
