[v2] Move SNP initialization to the CCP driver

[PATCH v2 02/10] x86/snp: drop WBINVD before setting SNPEn

Posted by Tycho Andersen 1 month ago

From: "Tycho Andersen (AMD)" <tycho@kernel.org>

WBINVD is required before SNP_INIT(_EX), but not before setting SNPEn,
since the ccp driver already does its own WBINVD before SNP_INIT (and this
one would be too early for that anyway...).

Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/virt/svm/sev.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c
index f404c609582c..5e07f103c271 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -524,9 +524,6 @@ int __init snp_rmptable_init(void)
 		memset(desc->rmp_entry, 0, desc->size);
 	}
 
-	/* Flush the caches to ensure that data is written before SNP is enabled. */
-	wbinvd_on_all_cpus();
-
 	/* MtrrFixDramModEn must be enabled on all the CPUs prior to enabling SNP. */
 	on_each_cpu(mfd_enable, NULL, 1);
 
-- 
2.53.0

[tip: x86/sev] x86/virt/sev: Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN

Posted by tip-bot2 for Tycho Andersen (AMD) 4 weeks, 1 day ago

The following commit has been merged into the x86/sev branch of tip:

Commit-ID:     99cf1fb58e68291d408b4c4484181cf88f081857
Gitweb:        https://git.kernel.org/tip/99cf1fb58e68291d408b4c4484181cf88f081857
Author:        Tycho Andersen (AMD) <tycho@kernel.org>
AuthorDate:    Mon, 09 Mar 2026 12:00:44 -06:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Mon, 09 Mar 2026 21:48:46 +01:00

x86/virt/sev: Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN

WBINVD is required before SNP_INIT(_EX), but not before setting
MSR_AMD64_SYSCFG_SNP_EN, since the ccp driver already does its own WBINVD
before SNP_INIT (and this one would be too early for that anyway...).

Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/20260309180053.2389118-3-tycho@kernel.org
---
 arch/x86/virt/svm/sev.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c
index f404c60..5e07f10 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -524,9 +524,6 @@ int __init snp_rmptable_init(void)
 		memset(desc->rmp_entry, 0, desc->size);
 	}
 
-	/* Flush the caches to ensure that data is written before SNP is enabled. */
-	wbinvd_on_all_cpus();
-
 	/* MtrrFixDramModEn must be enabled on all the CPUs prior to enabling SNP. */
 	on_each_cpu(mfd_enable, NULL, 1);