Re: [PATCH v7 02/45] x86/sev: detect/setup SEV/SME features earlier in boot

Venu Busireddy
2021-12-06T23:48:31Z

On 2021-11-10 16:06:48 -0600, Brijesh Singh wrote:
> From: Michael Roth <michael.roth@amd.com>
>
> sme_enable() handles feature detection for both SEV and SME. Future
> patches will also use it for SEV-SNP feature detection/setup, which
> will need to be done immediately after the first #VC handler is set up.
> Move it now in preparation.

The previous patch added the function sev_enable(), which has most of its
code duplicated in sme_enable(). Can sme_enable() be changed (and maybe
sev_enable() a bit) to call sev_enable() and avoid all the duplicate code?

Venu

>
> Signed-off-by: Michael Roth <michael.roth@amd.com>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
> arch/x86/include/asm/setup.h | 2 +-
> arch/x86/kernel/head64.c | 8 ++++----
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
> index a12458a7a8d4..cee1e816fdcd 100644
> --- a/arch/x86/include/asm/setup.h
> +++ b/arch/x86/include/asm/setup.h
> @@ -50,7 +50,7 @@ extern void reserve_standard_io_resources(void);
> extern void i386_reserve_resources(void);
> extern unsigned long __startup_64(unsigned long physaddr, struct boot_params *bp);
> extern unsigned long __startup_secondary_64(void);
> -extern void startup_64_setup_env(unsigned long physbase);
> +extern void startup_64_setup_env(unsigned long physbase, struct boot_params *bp);
> extern void early_setup_idt(void);
> extern void __init do_early_exception(struct pt_regs *regs, int trapnr);
>
> diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
> index fc5371a7e9d1..4eb83ae7ceb8 100644
> --- a/arch/x86/kernel/head64.c
> +++ b/arch/x86/kernel/head64.c
> @@ -163,9 +163,6 @@ unsigned long __head __startup_64(unsigned long physaddr,
> if (load_delta & ~PMD_PAGE_MASK)
> for (;;);
>
> - /* Activate Secure Memory Encryption (SME) if supported and enabled */
> - sme_enable(bp);
> -
> /* Include the SME encryption mask in the fixup value */
> load_delta += sme_get_me_mask();
>
> @@ -594,7 +591,7 @@ void early_setup_idt(void)
> /*
> * Setup boot CPU state needed before kernel switches to virtual addresses.
> */
> -void __head startup_64_setup_env(unsigned long physbase)
> +void __head startup_64_setup_env(unsigned long physbase, struct boot_params *bp)
> {
> /* Load GDT */
> startup_gdt_descr.address = (unsigned long)fixup_pointer(startup_gdt, physbase);
> @@ -606,4 +603,7 @@ void __head startup_64_setup_env(unsigned long physbase)
> "movl %%eax, %%es\n" : : "a"(__KERNEL_DS) : "memory");
>
> startup_64_load_idt(physbase);
> +
> + /* Activate SEV/SME memory encryption if supported/enabled. */
> + sme_enable(bp);
> }
> --
> 2.25.1
>