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-rw-r--r--arch/x86/include/asm/cpufeatures.h1
-rw-r--r--arch/x86/kernel/cpu/bugs.c4
-rw-r--r--arch/x86/kernel/cpu/common.c1
-rw-r--r--arch/x86/kvm/cpuid.c2
4 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 645aa360628d..0e2d81763615 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -465,6 +465,7 @@
#define X86_FEATURE_SBPB (20*32+27) /* Selective Branch Prediction Barrier */
#define X86_FEATURE_IBPB_BRTYPE (20*32+28) /* MSR_PRED_CMD[IBPB] flushes all branch type predictions */
#define X86_FEATURE_SRSO_NO (20*32+29) /* CPU is not affected by SRSO */
+#define X86_FEATURE_SRSO_USER_KERNEL_NO (20*32+30) /* CPU is not affected by SRSO across user/kernel boundaries */
/*
* Extended auxiliary flags: Linux defined - for features scattered in various
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 47a01d4028f6..5a505aa65489 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2615,6 +2615,9 @@ static void __init srso_select_mitigation(void)
break;
case SRSO_CMD_SAFE_RET:
+ if (boot_cpu_has(X86_FEATURE_SRSO_USER_KERNEL_NO))
+ goto ibpb_on_vmexit;
+
if (IS_ENABLED(CONFIG_MITIGATION_SRSO)) {
/*
* Enable the return thunk for generated code
@@ -2658,6 +2661,7 @@ static void __init srso_select_mitigation(void)
}
break;
+ibpb_on_vmexit:
case SRSO_CMD_IBPB_ON_VMEXIT:
if (IS_ENABLED(CONFIG_MITIGATION_SRSO)) {
if (!boot_cpu_has(X86_FEATURE_ENTRY_IBPB) && has_microcode) {
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 3e9037690814..7e8d811b51c8 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1270,6 +1270,7 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
VULNBL_AMD(0x17, RETBLEED | SMT_RSB | SRSO),
VULNBL_HYGON(0x18, RETBLEED | SMT_RSB | SRSO),
VULNBL_AMD(0x19, SRSO),
+ VULNBL_AMD(0x1a, SRSO),
{}
};
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index ae0b438a2c99..f7e222953cab 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -821,7 +821,7 @@ void kvm_set_cpu_caps(void)
kvm_cpu_cap_mask(CPUID_8000_0021_EAX,
F(NO_NESTED_DATA_BP) | F(LFENCE_RDTSC) | 0 /* SmmPgCfgLock */ |
F(NULL_SEL_CLR_BASE) | F(AUTOIBRS) | 0 /* PrefetchCtlMsr */ |
- F(WRMSR_XX_BASE_NS)
+ F(WRMSR_XX_BASE_NS) | F(SRSO_USER_KERNEL_NO)
);
kvm_cpu_cap_check_and_set(X86_FEATURE_SBPB);