diff options
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 41 |
1 files changed, 36 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index bc74c22e927c..2705105d9a5e 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -70,6 +70,9 @@ static void __init taa_apply_mitigation(void); static void __init mmio_select_mitigation(void); static void __init mmio_update_mitigation(void); static void __init mmio_apply_mitigation(void); +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 l1d_flush_select_mitigation(void); static void __init srso_select_mitigation(void); @@ -200,6 +203,7 @@ void __init cpu_select_mitigations(void) mds_select_mitigation(); taa_select_mitigation(); mmio_select_mitigation(); + rfds_select_mitigation(); md_clear_select_mitigation(); srbds_select_mitigation(); l1d_flush_select_mitigation(); @@ -218,10 +222,12 @@ void __init cpu_select_mitigations(void) mds_update_mitigation(); taa_update_mitigation(); mmio_update_mitigation(); + rfds_update_mitigation(); mds_apply_mitigation(); taa_apply_mitigation(); mmio_apply_mitigation(); + rfds_apply_mitigation(); } /* @@ -624,22 +630,48 @@ static const char * const rfds_strings[] = { [RFDS_MITIGATION_UCODE_NEEDED] = "Vulnerable: No microcode", }; +static inline bool __init verw_clears_cpu_reg_file(void) +{ + return (x86_arch_cap_msr & ARCH_CAP_RFDS_CLEAR); +} + static void __init rfds_select_mitigation(void) { if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off()) { rfds_mitigation = RFDS_MITIGATION_OFF; return; } + + if (rfds_mitigation == RFDS_MITIGATION_AUTO) + rfds_mitigation = RFDS_MITIGATION_VERW; + if (rfds_mitigation == RFDS_MITIGATION_OFF) return; - if (rfds_mitigation == RFDS_MITIGATION_AUTO) + if (verw_clears_cpu_reg_file()) + verw_clear_cpu_buf_mitigation_selected = true; +} + +static void __init rfds_update_mitigation(void) +{ + if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off()) + return; + + if (verw_clear_cpu_buf_mitigation_selected) rfds_mitigation = RFDS_MITIGATION_VERW; - if (x86_arch_cap_msr & ARCH_CAP_RFDS_CLEAR) + if (rfds_mitigation == RFDS_MITIGATION_VERW) { + if (!verw_clears_cpu_reg_file()) + rfds_mitigation = RFDS_MITIGATION_UCODE_NEEDED; + } + + pr_info("%s\n", rfds_strings[rfds_mitigation]); +} + +static void __init rfds_apply_mitigation(void) +{ + if (rfds_mitigation == RFDS_MITIGATION_VERW) setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF); - else - rfds_mitigation = RFDS_MITIGATION_UCODE_NEEDED; } static __init int rfds_parse_cmdline(char *str) @@ -712,7 +744,6 @@ out: static void __init md_clear_select_mitigation(void) { - rfds_select_mitigation(); /* * As these mitigations are inter-related and rely on VERW instruction |