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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-10-05 08:44:26 +0200 |
|---|---|---|
| committer |   Heiko Carstens <heiko.carstens@de.ibm.com> | 2017-11-14 11:01:43 +0100 |
| commit | c771320e9357c9b85634002daedfe5c8988f27a6 (patch) | |
| tree | bf405eb39a9cb33d352fddaf2edf3eeacf4eb74f /arch/s390/kernel | |
| parent | s390/ap_bus: Convert timers to use timer_setup() (diff) | |
| download | linux-dev-c771320e9357c9b85634002daedfe5c8988f27a6.tar.xz linux-dev-c771320e9357c9b85634002daedfe5c8988f27a6.zip | |
s390/mm,kvm: improve detection of KVM guest faults
The identification of guest fault currently relies on the PF_VCPU flag.
This is set in guest_entry_irqoff and cleared in guest_exit_irqoff.
Both functions are called by __vcpu_run, the PF_VCPU flag is set for
quite a lot of kernel code outside of the guest execution.
Replace the PF_VCPU scheme with the PIF_GUEST_FAULT in the pt_regs and
make the program check handler code in entry.S set the bit only for
exception that occurred between the .Lsie_gmap and .Lsie_done labels.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
| -rw-r--r-- | arch/s390/kernel/entry.S | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index f498d201f98d..ee53ac7b1ab8 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -518,6 +518,7 @@ ENTRY(pgm_check_handler) stmg %r8,%r15,__LC_SAVE_AREA_SYNC lg %r10,__LC_LAST_BREAK lg %r12,__LC_CURRENT + lghi %r11,0 larl %r13,cleanup_critical lmg %r8,%r9,__LC_PGM_OLD_PSW tmhh %r8,0x0001 # test problem state bit @@ -532,6 +533,7 @@ ENTRY(pgm_check_handler) ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce larl %r9,sie_exit # skip forward to sie_exit + lghi %r11,_PIF_GUEST_FAULT #endif 0: tmhh %r8,0x4000 # PER bit set in old PSW ? jnz 1f # -> enabled, can't be a double fault @@ -549,13 +551,14 @@ ENTRY(pgm_check_handler) jz 3f mvc __THREAD_trap_tdb(256,%r14),0(%r13) 3: stg %r10,__THREAD_last_break(%r14) -4: la %r11,STACK_FRAME_OVERHEAD(%r15) +4: lgr %r13,%r11 + la %r11,STACK_FRAME_OVERHEAD(%r15) stmg %r0,%r7,__PT_R0(%r11) mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC stmg %r8,%r9,__PT_PSW(%r11) mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC mvc __PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE - xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) + stg %r13,__PT_FLAGS(%r11) stg %r10,__PT_ARGS(%r11) tm __LC_PGM_ILC+3,0x80 # check for per exception jz 5f |