Messages in this thread Patch in this message | | | From | Smita Koralahalli <> | Subject | [PATCH v2 1/5] x86/mce/inject: Check if a bank is unpopulated before error injection | Date | Tue, 19 Oct 2021 18:36:37 -0500 |
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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.
On a "hw" error injection check the value of this register before trying to inject the error.
Do not impose any limitation on a "sw" injection and allow the user to test out all the decoding paths without relying on the available hardware, as its purpose is to just test the code.
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com> --- v2: simulate -> inject. Corrected according to kernel commenting style. boot_cpu_has() -> cpu_feature_enabled(). Error simulation not possible: Bank %llu unpopulated -> Cannot set IPID - bank %llu unpopulated. Used user provided IPID value on sw injection without checking underlying hardware and defined it under inj_ipid_set(). --- arch/x86/kernel/cpu/mce/inject.c | 39 +++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c index 0bfc14041bbb..601efd104bb4 100644 --- a/arch/x86/kernel/cpu/mce/inject.c +++ b/arch/x86/kernel/cpu/mce/inject.c @@ -74,7 +74,6 @@ MCE_INJECT_SET(status); MCE_INJECT_SET(misc); MCE_INJECT_SET(addr); MCE_INJECT_SET(synd); -MCE_INJECT_SET(ipid); #define MCE_INJECT_GET(reg) \ static int inj_##reg##_get(void *data, u64 *val) \ @@ -89,13 +88,11 @@ MCE_INJECT_GET(status); MCE_INJECT_GET(misc); MCE_INJECT_GET(addr); MCE_INJECT_GET(synd); -MCE_INJECT_GET(ipid); DEFINE_SIMPLE_ATTRIBUTE(status_fops, inj_status_get, inj_status_set, "%llx\n"); DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n"); DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n"); DEFINE_SIMPLE_ATTRIBUTE(synd_fops, inj_synd_get, inj_synd_set, "%llx\n"); -DEFINE_SIMPLE_ATTRIBUTE(ipid_fops, inj_ipid_get, inj_ipid_set, "%llx\n"); static void setup_inj_struct(struct mce *m) { @@ -577,6 +574,25 @@ 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 (cpu_feature_enabled(X86_FEATURE_SMCA)) { + + /* Check for user provided IPID value on a sw injection. */ + if (!m->ipid) { + rdmsrl_on_cpu(m->extcpu, MSR_AMD64_SMCA_MCx_IPID(val), + &m->ipid); + if (!m->ipid) { + pr_err("Cannot set IPID - bank %llu unpopulated\n", + val); + return -ENODEV; + } + } + } + do_inject(); /* Reset injection struct */ @@ -589,6 +605,23 @@ MCE_INJECT_GET(bank); DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n"); +/* Use the user provided IPID value on a sw injection. */ +static int inj_ipid_set(void *data, u64 val) +{ + struct mce *m = (struct mce *)data; + + if (cpu_feature_enabled(X86_FEATURE_SMCA)) { + if (val && inj_type == SW_INJ) + m->ipid = val; + } + + return 0; +} + +MCE_INJECT_GET(ipid); + +DEFINE_SIMPLE_ATTRIBUTE(ipid_fops, inj_ipid_get, inj_ipid_set, "%llx\n"); + static const char readme_msg[] = "Description of the files and their usages:\n" "\n" -- 2.17.1
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