| Message ID | ab92e0ec-d869-dae6-f47c-b7ac55bea326@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86/hvm: follow-up to f7039ee41b3d | expand |
> -----Original Message----- > From: Jan Beulich <jbeulich@suse.com> > Sent: 15 July 2020 13:05 > To: xen-devel@lists.xenproject.org > Cc: Andrew Cooper <andrew.cooper3@citrix.com>; Roger Pau Monné <roger.pau@citrix.com>; Wei Liu > <wl@xen.org>; Paul Durrant <paul@xen.org> > Subject: [PATCH 3/3] x86/HVM: fold both instances of looking up a hvm_ioreq_vcpu with a request > pending > > It seems pretty likely that the "break" in the loop getting replaced in > handle_hvm_io_completion() was meant to exit both nested loops at the > same time. Re-purpose what has been hvm_io_pending() to hand back the > struct hvm_ioreq_vcpu instance found, and use it to replace the two > nested loops. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> Yes, much neater... Reviewed-by: Paul Durrant <paul@xen.org> > > --- a/xen/arch/x86/hvm/ioreq.c > +++ b/xen/arch/x86/hvm/ioreq.c > @@ -81,7 +81,8 @@ static ioreq_t *get_ioreq(struct hvm_ior > return &p->vcpu_ioreq[v->vcpu_id]; > } > > -bool hvm_io_pending(struct vcpu *v) > +static struct hvm_ioreq_vcpu *get_pending_vcpu(const struct vcpu *v, > + struct hvm_ioreq_server **srvp) > { > struct domain *d = v->domain; > struct hvm_ioreq_server *s; > @@ -96,11 +97,20 @@ bool hvm_io_pending(struct vcpu *v) > list_entry ) > { > if ( sv->vcpu == v && sv->pending ) > - return true; > + { > + if ( srvp ) > + *srvp = s; > + return sv; > + } > } > } > > - return false; > + return NULL; > +} > + > +bool hvm_io_pending(struct vcpu *v) > +{ > + return get_pending_vcpu(v, NULL); > } > > static bool hvm_wait_for_io(struct hvm_ioreq_vcpu *sv, ioreq_t *p) > @@ -165,8 +175,8 @@ bool handle_hvm_io_completion(struct vcp > struct domain *d = v->domain; > struct hvm_vcpu_io *vio = &v->arch.hvm.hvm_io; > struct hvm_ioreq_server *s; > + struct hvm_ioreq_vcpu *sv; > enum hvm_io_completion io_completion; > - unsigned int id; > > if ( has_vpci(d) && vpci_process_pending(v) ) > { > @@ -174,23 +184,9 @@ bool handle_hvm_io_completion(struct vcp > return false; > } > > - FOR_EACH_IOREQ_SERVER(d, id, s) > - { > - struct hvm_ioreq_vcpu *sv; > - > - list_for_each_entry ( sv, > - &s->ioreq_vcpu_list, > - list_entry ) > - { > - if ( sv->vcpu == v && sv->pending ) > - { > - if ( !hvm_wait_for_io(sv, get_ioreq(s, v)) ) > - return false; > - > - break; > - } > - } > - } > + sv = get_pending_vcpu(v, &s); > + if ( sv && !hvm_wait_for_io(sv, get_ioreq(s, v)) ) > + return false; > > vio->io_req.state = hvm_ioreq_needs_completion(&vio->io_req) ? > STATE_IORESP_READY : STATE_IOREQ_NONE;
--- a/xen/arch/x86/hvm/ioreq.c +++ b/xen/arch/x86/hvm/ioreq.c @@ -81,7 +81,8 @@ static ioreq_t *get_ioreq(struct hvm_ior return &p->vcpu_ioreq[v->vcpu_id]; } -bool hvm_io_pending(struct vcpu *v) +static struct hvm_ioreq_vcpu *get_pending_vcpu(const struct vcpu *v, + struct hvm_ioreq_server **srvp) { struct domain *d = v->domain; struct hvm_ioreq_server *s; @@ -96,11 +97,20 @@ bool hvm_io_pending(struct vcpu *v) list_entry ) { if ( sv->vcpu == v && sv->pending ) - return true; + { + if ( srvp ) + *srvp = s; + return sv; + } } } - return false; + return NULL; +} + +bool hvm_io_pending(struct vcpu *v) +{ + return get_pending_vcpu(v, NULL); } static bool hvm_wait_for_io(struct hvm_ioreq_vcpu *sv, ioreq_t *p) @@ -165,8 +175,8 @@ bool handle_hvm_io_completion(struct vcp struct domain *d = v->domain; struct hvm_vcpu_io *vio = &v->arch.hvm.hvm_io; struct hvm_ioreq_server *s; + struct hvm_ioreq_vcpu *sv; enum hvm_io_completion io_completion; - unsigned int id; if ( has_vpci(d) && vpci_process_pending(v) ) { @@ -174,23 +184,9 @@ bool handle_hvm_io_completion(struct vcp return false; } - FOR_EACH_IOREQ_SERVER(d, id, s) - { - struct hvm_ioreq_vcpu *sv; - - list_for_each_entry ( sv, - &s->ioreq_vcpu_list, - list_entry ) - { - if ( sv->vcpu == v && sv->pending ) - { - if ( !hvm_wait_for_io(sv, get_ioreq(s, v)) ) - return false; - - break; - } - } - } + sv = get_pending_vcpu(v, &s); + if ( sv && !hvm_wait_for_io(sv, get_ioreq(s, v)) ) + return false; vio->io_req.state = hvm_ioreq_needs_completion(&vio->io_req) ? STATE_IORESP_READY : STATE_IOREQ_NONE;
It seems pretty likely that the "break" in the loop getting replaced in handle_hvm_io_completion() was meant to exit both nested loops at the same time. Re-purpose what has been hvm_io_pending() to hand back the struct hvm_ioreq_vcpu instance found, and use it to replace the two nested loops. Signed-off-by: Jan Beulich <jbeulich@suse.com>