Currently to trigger split lock exception at the guest side will print the
below to host logs.
"x86/split lock detection: #AC: CPU 1/KVM/65886 took a split_lock trap at
address: 0x401173"
Although it is more likely the split lock exception is from the guest side,
differentiate if it is from the guest side, or the host userspace
VMM (e.g., QEMU).
Signed-off-by: Dongli Zhang <[email protected]>
---
Changed since v1:
- Pass the string rather than bools (suggested by Dave Hansen)
arch/x86/kernel/cpu/intel.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index a927a8fc9624..26e45d9a66f2 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1155,14 +1155,14 @@ static int splitlock_cpu_offline(unsigned int cpu)
return 0;
}
-static void split_lock_warn(unsigned long ip)
+static void split_lock_warn(unsigned long ip, const char *from)
{
struct delayed_work *work;
int cpu;
if (!current->reported_split_lock)
- pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n",
- current->comm, current->pid, ip);
+ pr_warn_ratelimited("#AC: %s/%d (%s) took a split_lock trap at address: 0x%lx\n",
+ current->comm, current->pid, from, ip);
current->reported_split_lock = 1;
if (sysctl_sld_mitigate) {
@@ -1194,11 +1194,11 @@ static void split_lock_warn(unsigned long ip)
bool handle_guest_split_lock(unsigned long ip)
{
if (sld_state == sld_warn) {
- split_lock_warn(ip);
+ split_lock_warn(ip, "guest");
return true;
}
- pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n",
+ pr_warn_once("#AC: %s/%d %s (guest) split_lock trap at address: 0x%lx\n",
current->comm, current->pid,
sld_state == sld_fatal ? "fatal" : "bogus", ip);
@@ -1237,7 +1237,7 @@ bool handle_user_split_lock(struct pt_regs *regs, long error_code)
{
if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal)
return false;
- split_lock_warn(regs->ip);
+ split_lock_warn(regs->ip, "user");
return true;
}
--
2.34.1