[PATCH 1/5] x86/mce/inject: Check if a bank is unpopulated before error simulation
From: Smita Koralahalli <hidden>
Date: 2021-09-15 23:28:23
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 mce infrastructure · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Tony Luck
The MCA_IPID register uniquely identifies a bank's type on Scalable MCA (SMCA) systems. When an MCA bank is not populated, the MCA_IPID register will read as zero and writes to it will be ignored. Check the value of this register before trying to simulate the error. Signed-off-by: Smita Koralahalli <redacted> --- arch/x86/kernel/cpu/mce/inject.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c
index 0bfc14041bbb..51ac575c4605 100644
--- a/arch/x86/kernel/cpu/mce/inject.c
+++ b/arch/x86/kernel/cpu/mce/inject.c@@ -577,6 +577,24 @@ static int inj_bank_set(void *data, u64 val) } m->bank = val; + + /* Read IPID value to determine if a bank is unpopulated on the target + * CPU. + */ + if (boot_cpu_has(X86_FEATURE_SMCA)) { + + /* Check for user provided IPID value. */ + if (!m->ipid) { + rdmsrl_on_cpu(m->extcpu, MSR_AMD64_SMCA_MCx_IPID(val), + &m->ipid); + if (!m->ipid) { + pr_err("Error simulation not possible: Bank %llu unpopulated\n", + val); + return -ENODEV; + } + } + } + do_inject(); /* Reset injection struct */
--
2.17.1