On 7/15/25 22:18, 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>
> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
> arch/x86/boot/startup/sev-shared.c | 11 +++++++++++
> arch/x86/boot/startup/sev-startup.c | 5 ++---
> 2 files changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/boot/startup/sev-shared.c b/arch/x86/boot/startup/sev-shared.c
> index c401d0391537..60ab09b3149d 100644
> --- a/arch/x86/boot/startup/sev-shared.c
> +++ b/arch/x86/boot/startup/sev-shared.c
> @@ -723,6 +723,17 @@ static void __head setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
> }
> }
>
> +static int __head svsm_call_msr_protocol(struct svsm_call *call)
> +{
> + int ret;
> +
> + do {
> + ret = svsm_perform_msr_protocol(call);
> + } while (ret == -EAGAIN);
> +
> + return ret;
> +}
> +
> static void __head svsm_pval_4k_page(unsigned long paddr, bool validate)
> {
> struct svsm_pvalidate_call *pc;
> diff --git a/arch/x86/boot/startup/sev-startup.c b/arch/x86/boot/startup/sev-startup.c
> index 0b7e3b950183..c30e0eed0131 100644
> --- a/arch/x86/boot/startup/sev-startup.c
> +++ b/arch/x86/boot/startup/sev-startup.c
> @@ -295,7 +295,6 @@ static __head struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
> static __head void svsm_setup(struct cc_blob_sev_info *cc_info)
> {
> struct svsm_call call = {};
> - int ret;
> u64 pa;
>
> /*
> @@ -325,8 +324,8 @@ 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);
> - if (ret)
> +
> + if (svsm_perform_msr_protocol(&call))
This should be svsm_call_msr_protocol().
Thanks,
Tom
> sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CA_REMAP_FAIL);
>
> boot_svsm_caa = (struct svsm_ca *)pa;