s390/nmi: s390: New low level handling for machine check happening in guest (c929500d) · Commits · 戴 / test

arch/s390/include/asm/nmi.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -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)

arch/s390/include/asm/processor.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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__

arch/s390/kernel/asm-offsets.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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);

arch/s390/kernel/entry.S

+12 −1

Original line number	Diff line number	Diff line
		@@ -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
		@@ -1102,7 +1103,13 @@ 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
		@@ -1274,6 +1281,10 @@ 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"

arch/s390/kernel/nmi.c

+40 −10

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@
		#include <asm/crw.h>
		#include <asm/switch_to.h>
		#include <asm/ctl_reg.h>
		#include <asm/asm-offsets.h>

		struct mcck_struct {
		unsigned int kill_task : 1;
		@@ -280,6 +281,8 @@ static int notrace s390_validate_registers(union mci mci, int umode)
		#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 +294,7 @@ 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 +305,13 @@ 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;
		@@ -358,6 +368,12 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
		if (mcck->stp_queue)
		set_cpu_flag(CIF_MCCK_PENDING);
		}

		/*
		* 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();
		@@ -367,6 +383,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
		if (mci.ds && mci.fa)
		/* Storage degradation */
		s390_handle_damage();
		}
		if (mci.cp) {
		/* Channel report word pending */
		mcck->channel_report = 1;
		@@ -377,6 +394,19 @@ 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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