[tip: x86/bugs] x86/srso: Remove redundant X86_FEATURE_ENTRY_IBPB check

From: tip-bot2 for Josh Poimboeuf
Date: Fri Aug 25 2023 - 06:21:01 EST


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

Commit-ID: 071fcf6c28adcee293addd7258097949b8b54819
Gitweb: https://git.kernel.org/tip/071fcf6c28adcee293addd7258097949b8b54819
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Fri, 25 Aug 2023 00:01:49 -07:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 25 Aug 2023 11:22:01 +02:00

x86/srso: Remove redundant X86_FEATURE_ENTRY_IBPB check

The X86_FEATURE_ENTRY_IBPB check is redundant here due to the above
RETBLEED_MITIGATION_IBPB check. RETBLEED_MITIGATION_IBPB already
implies X86_FEATURE_ENTRY_IBPB. So if we got here and 'has_microcode'
is true, it means X86_FEATURE_ENTRY_IBPB is not set.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/9b671422643939792afe05c625e93ef40d9b57b5.1692919072.git.jpoimboe@xxxxxxxxxx
---
arch/x86/kernel/cpu/bugs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index b086fd4..563f09b 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2494,7 +2494,7 @@ static void __init srso_select_mitigation(void)

case SRSO_CMD_IBPB_ON_VMEXIT:
if (IS_ENABLED(CONFIG_CPU_SRSO)) {
- if (!boot_cpu_has(X86_FEATURE_ENTRY_IBPB) && has_microcode) {
+ if (has_microcode) {
setup_force_cpu_cap(X86_FEATURE_IBPB_ON_VMEXIT);
srso_mitigation = SRSO_MITIGATION_IBPB_ON_VMEXIT;
}