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-rw-r--r--arch/s390/kernel/nmi.c84
1 files changed, 74 insertions, 10 deletions
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 9855895..31d03a8 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -25,6 +25,8 @@
#include <asm/crw.h>
#include <asm/switch_to.h>
#include <asm/ctl_reg.h>
+#include <asm/asm-offsets.h>
+#include <linux/kvm_host.h>
struct mcck_struct {
unsigned int kill_task : 1;
@@ -274,12 +276,39 @@ static int notrace s390_validate_registers(union mci mci, int umode)
return kill_task;
}
+/*
+ * Backup the guest's machine check info to its description block
+ */
+static void notrace s390_backup_mcck_info(struct pt_regs *regs)
+{
+ struct mcck_volatile_info *mcck_backup;
+ struct sie_page *sie_page;
+
+ /* r14 contains the sie block, which was set in sie64a */
+ struct kvm_s390_sie_block *sie_block =
+ (struct kvm_s390_sie_block *) regs->gprs[14];
+
+ if (sie_block == NULL)
+ /* Something's seriously wrong, stop system. */
+ s390_handle_damage();
+
+ sie_page = container_of(sie_block, struct sie_page, sie_block);
+ mcck_backup = &sie_page->mcck_info;
+ mcck_backup->mcic = S390_lowcore.mcck_interruption_code &
+ ~(MCCK_CODE_CP | MCCK_CODE_EXT_DAMAGE);
+ mcck_backup->ext_damage_code = S390_lowcore.external_damage_code;
+ mcck_backup->failing_storage_address
+ = S390_lowcore.failing_storage_address;
+}
+
#define MAX_IPD_COUNT 29
#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
#define ED_STP_ISLAND 6 /* External damage STP island check */
#define ED_STP_SYNC 7 /* External damage STP sync check */
+#define MCCK_CODE_NO_GUEST (MCCK_CODE_CP | MCCK_CODE_EXT_DAMAGE)
+
/*
* machine check handler.
*/
@@ -291,6 +320,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
struct mcck_struct *mcck;
unsigned long long tmp;
union mci mci;
+ unsigned long mcck_dam_code;
nmi_enter();
inc_irq_stat(NMI_NMI);
@@ -301,7 +331,13 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
/* System damage -> stopping machine */
s390_handle_damage();
}
- if (mci.pd) {
+
+ /*
+ * Reinject the instruction processing damages' machine checks
+ * including Delayed Access Exception into the guest
+ * instead of damaging the host if they happen in the guest.
+ */
+ if (mci.pd && !test_cpu_flag(CIF_MCCK_GUEST)) {
if (mci.b) {
/* Processing backup -> verify if we can survive this */
u64 z_mcic, o_mcic, t_mcic;
@@ -345,6 +381,14 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
mcck->mcck_code = mci.val;
set_cpu_flag(CIF_MCCK_PENDING);
}
+
+ /*
+ * Backup the machine check's info if it happens when the guest
+ * is running.
+ */
+ if (test_cpu_flag(CIF_MCCK_GUEST))
+ s390_backup_mcck_info(regs);
+
if (mci.cd) {
/* Timing facility damage */
s390_handle_damage();
@@ -358,15 +402,22 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
if (mcck->stp_queue)
set_cpu_flag(CIF_MCCK_PENDING);
}
- if (mci.se)
- /* Storage error uncorrected */
- s390_handle_damage();
- if (mci.ke)
- /* Storage key-error uncorrected */
- s390_handle_damage();
- if (mci.ds && mci.fa)
- /* Storage degradation */
- s390_handle_damage();
+
+ /*
+ * Reinject storage related machine checks into the guest if they
+ * happen when the guest is running.
+ */
+ if (!test_cpu_flag(CIF_MCCK_GUEST)) {
+ if (mci.se)
+ /* Storage error uncorrected */
+ s390_handle_damage();
+ if (mci.ke)
+ /* Storage key-error uncorrected */
+ s390_handle_damage();
+ if (mci.ds && mci.fa)
+ /* Storage degradation */
+ s390_handle_damage();
+ }
if (mci.cp) {
/* Channel report word pending */
mcck->channel_report = 1;
@@ -377,6 +428,19 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
mcck->warning = 1;
set_cpu_flag(CIF_MCCK_PENDING);
}
+
+ /*
+ * If there are only Channel Report Pending and External Damage
+ * machine checks, they will not be reinjected into the guest
+ * because they refer to host conditions only.
+ */
+ mcck_dam_code = (mci.val & MCIC_SUBCLASS_MASK);
+ if (test_cpu_flag(CIF_MCCK_GUEST) &&
+ (mcck_dam_code & MCCK_CODE_NO_GUEST) != mcck_dam_code) {
+ /* Set exit reason code for host's later handling */
+ *((long *)(regs->gprs[15] + __SF_SIE_REASON)) = -EINTR;
+ }
+ clear_cpu_flag(CIF_MCCK_GUEST);
nmi_exit();
}
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