Commit c15a4705 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Borislav Petkov (AMD)
Browse files

x86/sev: Use MSR protocol for remapping SVSM calling area 



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: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/20250828102202.1849035-26-ardb+git@google.com
parent e2e29752

arch/x86/boot/startup/sev-shared.c

+11 −0
Original line number Diff line number Diff line
@@ -724,6 +724,17 @@ 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;

arch/x86/boot/startup/sev-startup.c

+2 −3
Original line number Diff line number Diff line
@@ -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_call_msr_protocol(&call))

		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CA_REMAP_FAIL);



	boot_svsm_caa = (struct svsm_ca *)pa;