On 30.09.2021 09:13, Oleksandr Andrushchenko wrote: > From: Oleksandr Andrushchenko <[email protected]> > > vPCI may map and unmap PCI device memory (BARs) being passed through which > may take a lot of time. For this those operations may be deferred to be > performed later, so that they can be safely preempted. > > Currently this deferred processing is happening in common IOREQ code > which doesn't seem to be the right place for x86 and is even more > doubtful because IOREQ may not be enabled for Arm at all. > So, for Arm the pending vPCI work may have no chance to be executed > if the processing is left as is in the common IOREQ code only. > For that reason make vPCI processing happen in arch specific code. > > Please be aware that there are a few outstanding TODOs affecting this > code path, see xen/drivers/vpci/header.c:map_range and > xen/drivers/vpci/header.c:vpci_process_pending. > > Signed-off-by: Oleksandr Andrushchenko <[email protected]> > > --- > Since v2: > - update commit message with more insight on x86, IOREQ and Arm > - restored order of invocation for IOREQ and vPCI processing (Jan) > Since v1: > - Moved the check for pending vpci work from the common IOREQ code > to hvm_do_resume on x86 > - Re-worked the code for Arm to ensure we don't miss pending vPCI work > --- > xen/arch/arm/traps.c | 13 +++++++++++++ > xen/arch/x86/hvm/hvm.c | 6 ++++++
This x86 change Acked-by: Jan Beulich <[email protected]> > xen/common/ioreq.c | 9 --------- Already on v2 I did indicate that you need to Cc Paul to get an ack for this part of the change. > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -546,6 +546,12 @@ void hvm_do_resume(struct vcpu *v) > > pt_restore_timer(v); > > + if ( has_vpci(v->domain) && vpci_process_pending(v) ) > + { > + raise_softirq(SCHEDULE_SOFTIRQ); > + return; > + } > + > if ( !vcpu_ioreq_handle_completion(v) ) > return; Seeing this movement I'm now wondering whether we shouldn't take the opportunity and move this further up. I notice that besides Paul you also failed to Cc the other x86 maintainers, whom I'm now adding. Jan > --- a/xen/common/ioreq.c > +++ b/xen/common/ioreq.c > @@ -25,9 +25,7 @@ > #include <xen/lib.h> > #include <xen/paging.h> > #include <xen/sched.h> > -#include <xen/softirq.h> > #include <xen/trace.h> > -#include <xen/vpci.h> > > #include <asm/guest_atomics.h> > #include <asm/ioreq.h> > @@ -212,19 +210,12 @@ static bool wait_for_io(struct ioreq_vcpu *sv, ioreq_t > *p) > > bool vcpu_ioreq_handle_completion(struct vcpu *v) > { > - struct domain *d = v->domain; > struct vcpu_io *vio = &v->io; > struct ioreq_server *s; > struct ioreq_vcpu *sv; > enum vio_completion completion; > bool res = true; > > - if ( has_vpci(d) && vpci_process_pending(v) ) > - { > - raise_softirq(SCHEDULE_SOFTIRQ); > - return false; > - } > - > while ( (sv = get_pending_vcpu(v, &s)) != NULL ) > if ( !wait_for_io(sv, get_ioreq(s, v)) ) > return false; >
