diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/s390/kernel/nmi.c | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index 1cf1e37553e8..31cb9b00a36b 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -6,12 +6,12 @@ * Author(s): Ingo Adlung <adlung@de.ibm.com>, * Martin Schwidefsky <schwidefsky@de.ibm.com>, * Cornelia Huck <cornelia.huck@de.ibm.com>, - * Heiko Carstens <heiko.carstens@de.ibm.com>, */ #include <linux/kernel_stat.h> #include <linux/init.h> #include <linux/errno.h> +#include <linux/entry-common.h> #include <linux/hardirq.h> #include <linux/log2.h> #include <linux/kprobes.h> @@ -30,6 +30,8 @@ #include <asm/switch_to.h> #include <asm/ctl_reg.h> #include <asm/asm-offsets.h> +#include <asm/pai.h> + #include <linux/kvm_host.h> struct mcck_struct { @@ -62,7 +64,7 @@ static inline unsigned long nmi_get_mcesa_size(void) * structure. The structure is required for machine check happening * early in the boot process. */ -static struct mcesa boot_mcesa __initdata __aligned(MCESA_MAX_SIZE); +static struct mcesa boot_mcesa __aligned(MCESA_MAX_SIZE); void __init nmi_alloc_mcesa_early(u64 *mcesad) { @@ -166,14 +168,16 @@ void __s390_handle_mcck(void) "malfunction (code 0x%016lx).\n", mcck.mcck_code); printk(KERN_EMERG "mcck: task: %s, pid: %d.\n", current->comm, current->pid); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } } -void noinstr s390_handle_mcck(void) +void noinstr s390_handle_mcck(struct pt_regs *regs) { trace_hardirqs_off(); + pai_kernel_enter(regs); __s390_handle_mcck(); + pai_kernel_exit(regs); trace_hardirqs_on(); } /* @@ -264,7 +268,14 @@ static int notrace s390_validate_registers(union mci mci, int umode) /* Validate vector registers */ union ctlreg0 cr0; - if (!mci.vr) { + /* + * The vector validity must only be checked if not running a + * KVM guest. For KVM guests the machine check is forwarded by + * KVM and it is the responsibility of the guest to take + * appropriate actions. The host vector or FPU values have been + * saved by KVM and will be restored by KVM. + */ + if (!mci.vr && !test_cpu_flag(CIF_MCCK_GUEST)) { /* * Vector registers can't be restored. If the kernel * currently uses vector registers the system is @@ -307,11 +318,21 @@ static int notrace s390_validate_registers(union mci mci, int umode) if (cr2.gse) { if (!mci.gs) { /* - * Guarded storage register can't be restored and - * the current processes uses guarded storage. - * It has to be terminated. + * 2 cases: + * - machine check in kernel or userspace + * - machine check while running SIE (KVM guest) + * For kernel or userspace the userspace values of + * guarded storage control can not be recreated, the + * process must be terminated. + * For SIE the guest values of guarded storage can not + * be recreated. This is either due to a bug or due to + * GS being disabled in the guest. The guest will be + * notified by KVM code and the guests machine check + * handling must take care of this. The host values + * are saved by KVM and are not affected. */ - kill_task = 1; + if (!test_cpu_flag(CIF_MCCK_GUEST)) + kill_task = 1; } else { load_gs_cb((struct gs_cb *)mcesa->guarded_storage_save_area); } @@ -377,11 +398,12 @@ int notrace s390_do_machine_check(struct pt_regs *regs) static unsigned long long last_ipd; struct mcck_struct *mcck; unsigned long long tmp; + irqentry_state_t irq_state; union mci mci; unsigned long mcck_dam_code; int mcck_pending = 0; - nmi_enter(); + irq_state = irqentry_nmi_enter(regs); if (user_mode(regs)) update_timer_mcck(); @@ -484,14 +506,14 @@ int notrace s390_do_machine_check(struct pt_regs *regs) clear_cpu_flag(CIF_MCCK_GUEST); if (user_mode(regs) && mcck_pending) { - nmi_exit(); + irqentry_nmi_exit(regs, irq_state); return 1; } if (mcck_pending) schedule_mcck_handler(); - nmi_exit(); + irqentry_nmi_exit(regs, irq_state); return 0; } NOKPROBE_SYMBOL(s390_do_machine_check); |