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x86/speculation/mmio: Print SMT warning

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commit 1dc6ff02c8bf77d71b9b5d11cbc9df77cfb28626 upstream

Similar to MDS and TAA, print a warning if SMT is enabled for the MMIO
Stale Data vulnerability.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Josh Poimboeuf 2022-05-23 09:11:49 -07:00 committed by Greg Kroah-Hartman
parent da06c60d1d
commit 71078b8216
1 changed files with 11 additions and 0 deletions
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11
arch/x86/kernel/cpu/bugs.c
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@ -1214,6 +1214,7 @@ static void update_mds_branch_idle(void)
#define MDS_MSG_SMT "MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for more details.\n"
#define TAA_MSG_SMT "TAA CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html for more details.\n"
#define MMIO_MSG_SMT "MMIO Stale Data CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/processor_mmio_stale_data.html for more details.\n"
void arch_smt_update(void)
{
@ -1258,6 +1259,16 @@ void arch_smt_update(void)
break;
}
switch (mmio_mitigation) {
case MMIO_MITIGATION_VERW:
case MMIO_MITIGATION_UCODE_NEEDED:
if (sched_smt_active())
pr_warn_once(MMIO_MSG_SMT);
break;
case MMIO_MITIGATION_OFF:
break;
}
mutex_unlock(&spec_ctrl_mutex);
}