[PATCH 17/37] kvm: Add MCE signal support for !CONFIG_IOTHREAD

Marcelo Tosatti
2011-02-14T15:25:09Z

Currently, we only configure and process MCE-related SIGBUS events if
CONFIG_IOTHREAD is enabled. The groundwork is laid, we just need to
factor out the required handler registration and system configuration.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
CC: Huang Ying <ying.huang@intel.com>
CC: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
CC: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
cpus.c | 107 +++++++++++++++++++++++++++++++++++++++-------------------------
1 files changed, 65 insertions(+), 42 deletions(-)

diff --git a/cpus.c b/cpus.c
index 38dd506..9a3fc31 100644
--- a/cpus.c
+++ b/cpus.c
@@ -34,9 +34,6 @@

#include "cpus.h"
#include "compatfd.h"
-#ifdef CONFIG_LINUX
-#include <sys/prctl.h>
-#endif

#ifdef SIGRTMIN
#define SIG_IPI (SIGRTMIN+4)
@@ -44,10 +41,24 @@
#define SIG_IPI SIGUSR1
#endif

+#ifdef CONFIG_LINUX
+
+#include <sys/prctl.h>
+
#ifndef PR_MCE_KILL
#define PR_MCE_KILL 33
#endif

+#ifndef PR_MCE_KILL_SET
+#define PR_MCE_KILL_SET 1
+#endif
+
+#ifndef PR_MCE_KILL_EARLY
+#define PR_MCE_KILL_EARLY 1
+#endif
+
+#endif /* CONFIG_LINUX */
+
static CPUState *next_cpu;

/***********************************************************/
@@ -158,6 +169,52 @@ static void cpu_debug_handler(CPUState *env)
vm_stop(EXCP_DEBUG);
}

+#ifdef CONFIG_LINUX
+static void sigbus_reraise(void)
+{
+ sigset_t set;
+ struct sigaction action;
+
+ memset(&action, 0, sizeof(action));
+ action.sa_handler = SIG_DFL;
+ if (!sigaction(SIGBUS, &action, NULL)) {
+ raise(SIGBUS);
+ sigemptyset(&set);
+ sigaddset(&set, SIGBUS);
+ sigprocmask(SIG_UNBLOCK, &set, NULL);
+ }
+ perror("Failed to re-raise SIGBUS!\n");
+ abort();
+}
+
+static void sigbus_handler(int n, struct qemu_signalfd_siginfo *siginfo,
+ void *ctx)
+{
+ if (kvm_on_sigbus(siginfo->ssi_code,
+ (void *)(intptr_t)siginfo->ssi_addr)) {
+ sigbus_reraise();
+ }
+}
+
+static void qemu_init_sigbus(void)
+{
+ struct sigaction action;
+
+ memset(&action, 0, sizeof(action));
+ action.sa_flags = SA_SIGINFO;
+ action.sa_sigaction = (void (*)(int, siginfo_t*, void*))sigbus_handler;
+ sigaction(SIGBUS, &action, NULL);
+
+ prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
+}
+
+#else /* !CONFIG_LINUX */
+
+static void qemu_init_sigbus(void)
+{
+}
+#endif /* !CONFIG_LINUX */
+
#ifndef _WIN32
static int io_thread_fd = -1;

@@ -280,8 +337,6 @@ static int qemu_signalfd_init(sigset_t mask)
return 0;
}

-static void sigbus_reraise(void);
-
static void qemu_kvm_eat_signals(CPUState *env)
{
struct timespec ts = { 0, 0 };
@@ -302,13 +357,11 @@ static void qemu_kvm_eat_signals(CPUState *env)
}

switch (r) {
-#ifdef CONFIG_IOTHREAD
case SIGBUS:
if (kvm_on_sigbus_vcpu(env, siginfo.si_code, siginfo.si_addr)) {
sigbus_reraise();
}
break;
-#endif
default:
break;
}
@@ -397,6 +450,7 @@ static sigset_t block_synchronous_signals(void)
sigset_t set;

sigemptyset(&set);
+ sigaddset(&set, SIGBUS);
if (kvm_enabled()) {
/*
* We need to process timer signals synchronously to avoid a race
@@ -425,6 +479,8 @@ int qemu_init_main_loop(void)
#endif
cpu_set_debug_excp_handler(cpu_debug_handler);

+ qemu_init_sigbus();
+
return qemu_event_init();
}

@@ -561,13 +617,9 @@ static void qemu_tcg_init_cpu_signals(void)
pthread_sigmask(SIG_UNBLOCK, &set, NULL);
}

-static void sigbus_handler(int n, struct qemu_signalfd_siginfo *siginfo,
- void *ctx);
-
static sigset_t block_io_signals(void)
{
sigset_t set;
- struct sigaction action;

/* SIGUSR2 used by posix-aio-compat.c */
sigemptyset(&set);
@@ -581,12 +633,6 @@ static sigset_t block_io_signals(void)
sigaddset(&set, SIGBUS);
pthread_sigmask(SIG_BLOCK, &set, NULL);

- memset(&action, 0, sizeof(action));
- action.sa_flags = SA_SIGINFO;
- action.sa_sigaction = (void (*)(int, siginfo_t*, void*))sigbus_handler;
- sigaction(SIGBUS, &action, NULL);
- prctl(PR_MCE_KILL, 1, 1, 0, 0);
-
return set;
}

@@ -597,6 +643,8 @@ int qemu_init_main_loop(void)

cpu_set_debug_excp_handler(cpu_debug_handler);

+ qemu_init_sigbus();
+
blocked_signals = block_io_signals();

ret = qemu_signalfd_init(blocked_signals);
@@ -704,31 +752,6 @@ static void qemu_tcg_wait_io_event(void)
}
}

-static void sigbus_reraise(void)
-{
- sigset_t set;
- struct sigaction action;
-
- memset(&action, 0, sizeof(action));
- action.sa_handler = SIG_DFL;
- if (!sigaction(SIGBUS, &action, NULL)) {
- raise(SIGBUS);
- sigemptyset(&set);
- sigaddset(&set, SIGBUS);
- sigprocmask(SIG_UNBLOCK, &set, NULL);
- }
- perror("Failed to re-raise SIGBUS!\n");
- abort();
-}
-
-static void sigbus_handler(int n, struct qemu_signalfd_siginfo *siginfo,
- void *ctx)
-{
- if (kvm_on_sigbus(siginfo->ssi_code, (void *)(intptr_t)siginfo->ssi_addr)) {
- sigbus_reraise();
- }
-}
-
static void qemu_kvm_wait_io_event(CPUState *env)
{
while (!cpu_has_work(env))
--
1.7.4