On 7/9/2016 7:23 AM, Corneliu ZUZU wrote:
Enforce presence of a monitor vm-event subscriber when the toolstack user calls xc_monitor_write_ctrlreg() (XEN_DOMCTL_MONITOR_EVENT_WRITE_CTRLREG domctl). Without this change, "ASSERT(monitor_domain_initialised(v->domain));" @ hvm_set_cr0() and such would fail if the toolstack user calls xc_monitor_write_ctrlreg(...) w/ enable = true, without first calling xc_monitor_enable().Also adjust returned error code for similar check from -EINVAL to more descriptive -ENODEV (XEN_DOMCTL_MONITOR_OP_EMULATE_EACH_REP). Signed-off-by: Corneliu ZUZU <cz...@bitdefender.com> --- xen/arch/x86/monitor.c | 4 ++++ xen/include/asm-x86/monitor.h | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/monitor.c b/xen/arch/x86/monitor.c index 05a2f0d..4cf018a 100644 --- a/xen/arch/x86/monitor.c +++ b/xen/arch/x86/monitor.c @@ -324,6 +324,10 @@ int arch_monitor_domctl_event(struct domain *d, unsigned int ctrlreg_bitmask; bool_t old_status;+ /* Meaningless without a monitor vm-events subscriber. */+ if ( unlikely(!monitor_domain_initialised(d)) ) + return -ENODEV; + /* sanity check: avoid left-shift undefined behavior */ if ( unlikely(mop->u.mov_to_cr.index > 31) ) return -EINVAL; diff --git a/xen/include/asm-x86/monitor.h b/xen/include/asm-x86/monitor.h index 11497ef..a6022db 100644 --- a/xen/include/asm-x86/monitor.h +++ b/xen/include/asm-x86/monitor.h @@ -47,7 +47,7 @@ int arch_monitor_domctl_op(struct domain *d, struct xen_domctl_monitor_op *mop) if ( likely(monitor_domain_initialised(d)) ) d->arch.mem_access_emulate_each_rep = !!mop->event; else - rc = -EINVAL; + rc = -ENODEV;domain_unpause(d);break;
I might have forgotten to think about domain pausing (for all patches), where it needs to be done. I'll leave that for v2 (obviously), I just wanted to let you know in case you guys have feedback on the matter until then.
Zuzu. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
