diff options
| -rw-r--r-- | hw/s390x/css.c | 51 |
1 files changed, 48 insertions, 3 deletions
diff --git a/hw/s390x/css.c b/hw/s390x/css.c index 7d9523f..95d1b3a 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -1522,21 +1522,37 @@ IOInstEnding css_do_xsch(SubchDev *sch) IOInstEnding css_do_csch(SubchDev *sch) { SCHIB *schib = &sch->curr_status; + uint16_t old_scsw_ctrl; + IOInstEnding ccode; if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) { return IOINST_CC_NOT_OPERATIONAL; } + /* + * Save the current scsw.ctrl in case CSCH fails and we need + * to revert the scsw to the status quo ante. + */ + old_scsw_ctrl = schib->scsw.ctrl; + /* Trigger the clear function. */ schib->scsw.ctrl &= ~(SCSW_CTRL_MASK_FCTL | SCSW_CTRL_MASK_ACTL); schib->scsw.ctrl |= SCSW_FCTL_CLEAR_FUNC | SCSW_ACTL_CLEAR_PEND; - return do_subchannel_work(sch); + ccode = do_subchannel_work(sch); + + if (ccode != IOINST_CC_EXPECTED) { + schib->scsw.ctrl = old_scsw_ctrl; + } + + return ccode; } IOInstEnding css_do_hsch(SubchDev *sch) { SCHIB *schib = &sch->curr_status; + uint16_t old_scsw_ctrl; + IOInstEnding ccode; if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) { return IOINST_CC_NOT_OPERATIONAL; @@ -1553,6 +1569,12 @@ IOInstEnding css_do_hsch(SubchDev *sch) return IOINST_CC_BUSY; } + /* + * Save the current scsw.ctrl in case HSCH fails and we need + * to revert the scsw to the status quo ante. + */ + old_scsw_ctrl = schib->scsw.ctrl; + /* Trigger the halt function. */ schib->scsw.ctrl |= SCSW_FCTL_HALT_FUNC; schib->scsw.ctrl &= ~SCSW_FCTL_START_FUNC; @@ -1564,7 +1586,13 @@ IOInstEnding css_do_hsch(SubchDev *sch) } schib->scsw.ctrl |= SCSW_ACTL_HALT_PEND; - return do_subchannel_work(sch); + ccode = do_subchannel_work(sch); + + if (ccode != IOINST_CC_EXPECTED) { + schib->scsw.ctrl = old_scsw_ctrl; + } + + return ccode; } static void css_update_chnmon(SubchDev *sch) @@ -1605,6 +1633,8 @@ static void css_update_chnmon(SubchDev *sch) IOInstEnding css_do_ssch(SubchDev *sch, ORB *orb) { SCHIB *schib = &sch->curr_status; + uint16_t old_scsw_ctrl, old_scsw_flags; + IOInstEnding ccode; if (~(schib->pmcw.flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) { return IOINST_CC_NOT_OPERATIONAL; @@ -1626,11 +1656,26 @@ IOInstEnding css_do_ssch(SubchDev *sch, ORB *orb) } sch->orb = *orb; sch->channel_prog = orb->cpa; + + /* + * Save the current scsw.ctrl and scsw.flags in case SSCH fails and we need + * to revert the scsw to the status quo ante. + */ + old_scsw_ctrl = schib->scsw.ctrl; + old_scsw_flags = schib->scsw.flags; + /* Trigger the start function. */ schib->scsw.ctrl |= (SCSW_FCTL_START_FUNC | SCSW_ACTL_START_PEND); schib->scsw.flags &= ~SCSW_FLAGS_MASK_PNO; - return do_subchannel_work(sch); + ccode = do_subchannel_work(sch); + + if (ccode != IOINST_CC_EXPECTED) { + schib->scsw.ctrl = old_scsw_ctrl; + schib->scsw.flags = old_scsw_flags; + } + + return ccode; } static void copy_irb_to_guest(IRB *dest, const IRB *src, const PMCW *pmcw, |