[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20241105215455.359471-10-david.kaplan@amd.com>
Date: Tue, 5 Nov 2024 15:54:29 -0600
From: David Kaplan <david.kaplan@....com>
To: Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...en8.de>,
Peter Zijlstra <peterz@...radead.org>, Josh Poimboeuf <jpoimboe@...nel.org>,
Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>, Ingo Molnar
<mingo@...hat.com>, Dave Hansen <dave.hansen@...ux.intel.com>,
<x86@...nel.org>, "H . Peter Anvin" <hpa@...or.com>
CC: <linux-kernel@...r.kernel.org>
Subject: [PATCH v2 09/35] x86/bugs: Restructure srbds mitigation
Restructure srbds to use select/apply functions to create consistent
vulnerability handling.
Define new AUTO mitigation for SRBDS.
Signed-off-by: David Kaplan <david.kaplan@....com>
---
arch/x86/kernel/cpu/bugs.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 5ad989e8eea3..452aa5994aac 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -72,6 +72,7 @@ static void __init rfds_select_mitigation(void);
static void __init rfds_update_mitigation(void);
static void __init rfds_apply_mitigation(void);
static void __init srbds_select_mitigation(void);
+static void __init srbds_apply_mitigation(void);
static void __init l1d_flush_select_mitigation(void);
static void __init srso_select_mitigation(void);
static void __init gds_select_mitigation(void);
@@ -218,6 +219,7 @@ void __init cpu_select_mitigations(void)
taa_apply_mitigation();
mmio_apply_mitigation();
rfds_apply_mitigation();
+ srbds_apply_mitigation();
}
/*
@@ -663,6 +665,7 @@ early_param("reg_file_data_sampling", rfds_parse_cmdline);
enum srbds_mitigations {
SRBDS_MITIGATION_OFF,
+ SRBDS_MITIGATION_AUTO,
SRBDS_MITIGATION_UCODE_NEEDED,
SRBDS_MITIGATION_FULL,
SRBDS_MITIGATION_TSX_OFF,
@@ -670,7 +673,7 @@ enum srbds_mitigations {
};
static enum srbds_mitigations srbds_mitigation __ro_after_init =
- IS_ENABLED(CONFIG_MITIGATION_SRBDS) ? SRBDS_MITIGATION_FULL : SRBDS_MITIGATION_OFF;
+ IS_ENABLED(CONFIG_MITIGATION_SRBDS) ? SRBDS_MITIGATION_AUTO : SRBDS_MITIGATION_OFF;
static const char * const srbds_strings[] = {
[SRBDS_MITIGATION_OFF] = "Vulnerable",
@@ -724,6 +727,9 @@ static void __init srbds_select_mitigation(void)
if (!boot_cpu_has_bug(X86_BUG_SRBDS))
return;
+ if (srbds_mitigation == SRBDS_MITIGATION_AUTO)
+ srbds_mitigation = SRBDS_MITIGATION_FULL;
+
/*
* Check to see if this is one of the MDS_NO systems supporting TSX that
* are only exposed to SRBDS when TSX is enabled or when CPU is affected
@@ -738,6 +744,12 @@ static void __init srbds_select_mitigation(void)
srbds_mitigation = SRBDS_MITIGATION_UCODE_NEEDED;
else if (cpu_mitigations_off() || srbds_off)
srbds_mitigation = SRBDS_MITIGATION_OFF;
+}
+
+static void __init srbds_apply_mitigation(void)
+{
+ if (!boot_cpu_has_bug(X86_BUG_SRBDS))
+ return;
update_srbds_msr();
pr_info("%s\n", srbds_strings[srbds_mitigation]);
--
2.34.1
Powered by blists - more mailing lists