[PATCH 02/12] X86/mce/inject: Add mcgstatus for mce-inject debugfs

From: isaku . yamahata
Date: Tue Oct 10 2023 - 04:35:56 EST


From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

To test KVM x86 to inject machine check with memory failure, it wants to
to set LMCE_S (local machine check exception signaled) for memory failure
injection test. The current code sets mcgstatus based on the other values
and can't set LMCE_S flag.

Add mcgstatus entry to allow to set mcgstatus value.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/kernel/cpu/mce/inject.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c
index 881898a1d2f4..461858ae18f9 100644
--- a/arch/x86/kernel/cpu/mce/inject.c
+++ b/arch/x86/kernel/cpu/mce/inject.c
@@ -72,6 +72,7 @@ static int inj_##reg##_set(void *data, u64 val) \
return 0; \
}

+MCE_INJECT_SET(mcgstatus);
MCE_INJECT_SET(status);
MCE_INJECT_SET(misc);
MCE_INJECT_SET(addr);
@@ -86,12 +87,14 @@ static int inj_##reg##_get(void *data, u64 *val) \
return 0; \
}

+MCE_INJECT_GET(mcgstatus);
MCE_INJECT_GET(status);
MCE_INJECT_GET(misc);
MCE_INJECT_GET(addr);
MCE_INJECT_GET(synd);
MCE_INJECT_GET(ipid);

+DEFINE_SIMPLE_ATTRIBUTE(mcgstatus_fops, inj_mcgstatus_get, inj_mcgstatus_set, "%llx\n");
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");
@@ -679,6 +682,9 @@ static const char readme_msg[] =
"\t APIC interrupt handler to handle the error. \n"
"\n"
"ipid:\t IPID (AMD-specific)\n"
+"\n"
+"mcgstatus:\t Set MCG_STATUS: the bits in that MSR describes the current state\n"
+"\t of the processor after the MCE.\n"
"\n";

static ssize_t
@@ -706,6 +712,8 @@ static struct dfs_node {
{ .name = "bank", .fops = &bank_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "flags", .fops = &flags_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "cpu", .fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "mcgstatus", .fops = &mcgstatus_fops,
+ .perm = S_IRUSR | S_IWUSR },
{ .name = "README", .fops = &readme_fops, .perm = S_IRUSR | S_IRGRP | S_IROTH },
};

--
2.25.1