On Mon, May 12, 2025 at 09:08:37PM +0200, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@kernel.org>
>
> As the preceding code comment already indicates, remapping the SVSM
> calling area occurs long before the GHCB page is configured, and so
> calling svsm_perform_call_protocol() is guaranteed to result in a call
> to svsm_perform_msr_protocol().
>
> So just call the latter directly. This allows most of the GHCB based API
> infrastructure to be moved out of the startup code in a subsequent
> patch.
>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> ---
> arch/x86/boot/startup/sev-startup.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/boot/startup/sev-startup.c b/arch/x86/boot/startup/sev-startup.c
> index 435853a55768..a1d5a5632d58 100644
> --- a/arch/x86/boot/startup/sev-startup.c
> +++ b/arch/x86/boot/startup/sev-startup.c
> @@ -325,7 +325,9 @@ static __head void svsm_setup(struct cc_blob_sev_info *cc_info)
> call.caa = svsm_get_caa();
> call.rax = SVSM_CORE_CALL(SVSM_CORE_REMAP_CA);
> call.rcx = pa;
> - ret = svsm_perform_call_protocol(&call);
> + do {
> + ret = svsm_perform_msr_protocol(&call);
> + } while (ret == -EAGAIN);
Right, a future cleanup for another patch would be to wrap that loop into
a function. But not now.
> if (ret)
> sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CA_REMAP_FAIL);
>
> --
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette