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author | Christian Borntraeger <borntraeger@de.ibm.com> | 2017-06-28 12:42:02 +0200 |
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committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2017-06-28 12:42:02 +0200 |
commit | aec3b2c5f929c31d5517e36e2068617179d0fefd (patch) | |
tree | 03101df13c1c2a156c04cedc18d42a246ae26c51 /arch | |
parent | 1cae025577f447fa69e55f194b1f3b078f5fbc25 (diff) | |
parent | da72ca4d4090a8ab0e6b0a23682ef42d39d7ae00 (diff) | |
download | linux-aec3b2c5f929c31d5517e36e2068617179d0fefd.tar.bz2 |
Merge tag 'nmiforkvm' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kernelorgnext
s390,kvm: provide plumbing for machines checks when running guests
This provides the basic plumbing for handling machine checks when
running guests
Diffstat (limited to 'arch')
-rw-r--r-- | arch/s390/include/asm/kvm_host.h | 17 | ||||
-rw-r--r-- | arch/s390/include/asm/nmi.h | 7 | ||||
-rw-r--r-- | arch/s390/include/asm/processor.h | 2 | ||||
-rw-r--r-- | arch/s390/kernel/asm-offsets.c | 3 | ||||
-rw-r--r-- | arch/s390/kernel/entry.S | 13 | ||||
-rw-r--r-- | arch/s390/kernel/nmi.c | 84 | ||||
-rw-r--r-- | arch/s390/kvm/kvm-s390.c | 1 |
7 files changed, 115 insertions, 12 deletions
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 72bad6753d97..41142d7cf988 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -109,6 +109,20 @@ struct esca_block { struct esca_entry cpu[KVM_S390_ESCA_CPU_SLOTS]; }; +/* + * This struct is used to store some machine check info from lowcore + * for machine checks that happen while the guest is running. + * This info in host's lowcore might be overwritten by a second machine + * check from host when host is in the machine check's high-level handling. + * The size is 24 bytes. + */ +struct mcck_volatile_info { + __u64 mcic; + __u64 failing_storage_address; + __u32 ext_damage_code; + __u32 reserved; +}; + #define CPUSTAT_STOPPED 0x80000000 #define CPUSTAT_WAIT 0x10000000 #define CPUSTAT_ECALL_PEND 0x08000000 @@ -266,7 +280,8 @@ struct kvm_s390_itdb { struct sie_page { struct kvm_s390_sie_block sie_block; - __u8 reserved200[1024]; /* 0x0200 */ + struct mcck_volatile_info mcck_info; /* 0x0200 */ + __u8 reserved218[1000]; /* 0x0218 */ struct kvm_s390_itdb itdb; /* 0x0600 */ __u8 reserved700[2304]; /* 0x0700 */ }; diff --git a/arch/s390/include/asm/nmi.h b/arch/s390/include/asm/nmi.h index e3e8895f5d3e..13623b9991d4 100644 --- a/arch/s390/include/asm/nmi.h +++ b/arch/s390/include/asm/nmi.h @@ -14,7 +14,14 @@ #include <linux/const.h> #include <linux/types.h> +#define MCIC_SUBCLASS_MASK (1ULL<<63 | 1ULL<<62 | 1ULL<<61 | \ + 1ULL<<59 | 1ULL<<58 | 1ULL<<56 | \ + 1ULL<<55 | 1ULL<<54 | 1ULL<<53 | \ + 1ULL<<52 | 1ULL<<47 | 1ULL<<46 | \ + 1ULL<<45 | 1ULL<<44) #define MCCK_CODE_SYSTEM_DAMAGE _BITUL(63) +#define MCCK_CODE_EXT_DAMAGE _BITUL(63 - 5) +#define MCCK_CODE_CP _BITUL(63 - 9) #define MCCK_CODE_CPU_TIMER_VALID _BITUL(63 - 46) #define MCCK_CODE_PSW_MWP_VALID _BITUL(63 - 20) #define MCCK_CODE_PSW_IA_VALID _BITUL(63 - 23) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 60d395fdc864..5b1b247dfbca 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -20,6 +20,7 @@ #define CIF_FPU 4 /* restore FPU registers */ #define CIF_IGNORE_IRQ 5 /* ignore interrupt (for udelay) */ #define CIF_ENABLED_WAIT 6 /* in enabled wait state */ +#define CIF_MCCK_GUEST 7 /* machine check happening in guest */ #define _CIF_MCCK_PENDING _BITUL(CIF_MCCK_PENDING) #define _CIF_ASCE_PRIMARY _BITUL(CIF_ASCE_PRIMARY) @@ -28,6 +29,7 @@ #define _CIF_FPU _BITUL(CIF_FPU) #define _CIF_IGNORE_IRQ _BITUL(CIF_IGNORE_IRQ) #define _CIF_ENABLED_WAIT _BITUL(CIF_ENABLED_WAIT) +#define _CIF_MCCK_GUEST _BITUL(CIF_MCCK_GUEST) #ifndef __ASSEMBLY__ diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index 6bb29633e1f1..b65c414b6c0e 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -58,6 +58,9 @@ int main(void) OFFSET(__SF_BACKCHAIN, stack_frame, back_chain); OFFSET(__SF_GPRS, stack_frame, gprs); OFFSET(__SF_EMPTY, stack_frame, empty1); + OFFSET(__SF_SIE_CONTROL, stack_frame, empty1[0]); + OFFSET(__SF_SIE_SAVEAREA, stack_frame, empty1[1]); + OFFSET(__SF_SIE_REASON, stack_frame, empty1[2]); BLANK(); /* timeval/timezone offsets for use by vdso */ OFFSET(__VDSO_UPD_COUNT, vdso_data, tb_update_count); diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index e408d9cc5b96..3b4b158382ea 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -225,6 +225,7 @@ ENTRY(sie64a) jnz .Lsie_skip TSTMSK __LC_CPU_FLAGS,_CIF_FPU jo .Lsie_skip # exit if fp/vx regs changed +.Lsie_entry: sie 0(%r14) .Lsie_skip: ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE @@ -1104,7 +1105,13 @@ cleanup_critical: .quad .Lsie_done .Lcleanup_sie: - lg %r9,__SF_EMPTY(%r15) # get control block pointer + cghi %r11,__LC_SAVE_AREA_ASYNC #Is this in normal interrupt? + je 1f + slg %r9,BASED(.Lsie_crit_mcck_start) + clg %r9,BASED(.Lsie_crit_mcck_length) + jh 1f + oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST +1: lg %r9,__SF_EMPTY(%r15) # get control block pointer ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce larl %r9,sie_exit # skip forward to sie_exit @@ -1289,6 +1296,10 @@ cleanup_critical: .quad .Lsie_gmap .Lsie_critical_length: .quad .Lsie_done - .Lsie_gmap +.Lsie_crit_mcck_start: + .quad .Lsie_entry +.Lsie_crit_mcck_length: + .quad .Lsie_skip - .Lsie_entry #endif .section .rodata, "a" diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index 985589523970..31d03a84126c 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(); } diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index e100a7ff35c7..90434760cda5 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2405,6 +2405,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, if (!vcpu) goto out; + BUILD_BUG_ON(sizeof(struct sie_page) != 4096); sie_page = (struct sie_page *) get_zeroed_page(GFP_KERNEL); if (!sie_page) goto out_free_cpu; |