From: Wanpeng Li <wanpengli@xxxxxxxxxxx> kvm_memslots() will be called by kvm_write_guest_offset_cached() so take the srcu lock. Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx> --- arch/x86/kvm/xen.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index ae17250..d0df782 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -96,6 +96,7 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) struct kvm_vcpu_xen *vx = &v->arch.xen; uint64_t state_entry_time; unsigned int offset; + int idx; kvm_xen_update_runstate(v, state); @@ -133,10 +134,16 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) BUILD_BUG_ON(sizeof(((struct compat_vcpu_runstate_info *)0)->state_entry_time) != sizeof(state_entry_time)); + /* + * Take the srcu lock as memslots will be accessed to check the gfn + * cache generation against the memslots generation. + */ + idx = srcu_read_lock(&v->kvm->srcu); + if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache, &state_entry_time, offset, sizeof(state_entry_time))) - return; + goto out; smp_wmb(); /* @@ -154,7 +161,7 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) &vx->current_runstate, offsetof(struct vcpu_runstate_info, state), sizeof(vx->current_runstate))) - return; + goto out; /* * Write the actual runstate times immediately after the @@ -173,7 +180,7 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) &vx->runstate_times[0], offset + sizeof(u64), sizeof(vx->runstate_times))) - return; + goto out; smp_wmb(); @@ -186,7 +193,10 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache, &state_entry_time, offset, sizeof(state_entry_time))) - return; + goto out; + +out: + srcu_read_unlock(&v->kvm->srcu, idx); } int __kvm_xen_has_interrupt(struct kvm_vcpu *v) -- 2.7.4
