| Message ID | 20180206203048.11096-19-rkagan@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/02/2018 21:30, Roman Kagan wrote: > When setting up a notifier for Hyper-V event connection, attempt to use > the KVM-assisted one first, and fall back to userspace handling of the > hypercall if the kernel doesn't provide the requested feature. > > Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> As before, I wouldn't mind dropping userspace SIGNAL_EVENT altogether. It would probably end up in bitrot. Thanks, Paolo > --- > include/sysemu/kvm.h | 1 + > accel/kvm/kvm-all.c | 15 +++++++++++++++ > target/i386/hyperv.c | 21 ++++++++++++++++++++- > 3 files changed, 36 insertions(+), 1 deletion(-) > > diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h > index bbf12a1723..70ad0a54b7 100644 > --- a/include/sysemu/kvm.h > +++ b/include/sysemu/kvm.h > @@ -496,6 +496,7 @@ void kvm_irqchip_set_qemuirq_gsi(KVMState *s, qemu_irq irq, int gsi); > void kvm_pc_gsi_handler(void *opaque, int n, int level); > void kvm_pc_setup_irq_routing(bool pci_enabled); > void kvm_init_irq_routing(KVMState *s); > +int kvm_set_hv_event_notifier(KVMState *s, uint32_t conn_id, EventNotifier *n); > > /** > * kvm_arch_irqchip_create: > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index f290f487a5..c3ba87b701 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -1423,6 +1423,21 @@ static void kvm_irqchip_create(MachineState *machine, KVMState *s) > s->gsimap = g_hash_table_new(g_direct_hash, g_direct_equal); > } > > +int kvm_set_hv_event_notifier(KVMState *s, uint32_t conn_id, EventNotifier *n) > +{ > + struct kvm_hyperv_eventfd hvevfd = { > + .conn_id = conn_id, > + .fd = n ? event_notifier_get_fd(n) : -1, > + .flags = n ? 0 : KVM_HYPERV_EVENTFD_DEASSIGN, > + }; > + > + if (!kvm_check_extension(s, KVM_CAP_HYPERV_EVENTFD)) { > + return -ENOSYS; > + } > + > + return kvm_vm_ioctl(s, KVM_HYPERV_EVENTFD, &hvevfd); > +} > + > /* Find number of supported CPUs using the recommended > * procedure from the kernel API documentation to cope with > * older kernels that may be missing capabilities. > diff --git a/target/i386/hyperv.c b/target/i386/hyperv.c > index e43cbb9322..63dcb23fa8 100644 > --- a/target/i386/hyperv.c > +++ b/target/i386/hyperv.c > @@ -313,7 +313,8 @@ unlock: > return ret; > } > > -int hyperv_set_evt_notifier(uint32_t conn_id, EventNotifier *notifier) > +static int hyperv_set_evt_notifier_userspace(uint32_t conn_id, > + EventNotifier *notifier) > { > int ret; > EvtHandler *eh; > @@ -346,6 +347,24 @@ unlock: > return ret; > } > > +static bool hv_evt_notifier_userspace; > + > +int hyperv_set_evt_notifier(uint32_t conn_id, EventNotifier *notifier) > +{ > + if (!hv_evt_notifier_userspace) { > + int ret = kvm_set_hv_event_notifier(kvm_state, conn_id, notifier); > + if (ret != -ENOSYS) { > + return ret; > + } > + > + hv_evt_notifier_userspace = true; > + warn_report("Hyper-V event signaling in KVM not supported; " > + "using slower userspace hypercall processing"); > + } > + > + return hyperv_set_evt_notifier_userspace(conn_id, notifier); > +} > + > static uint64_t hvcall_post_message(uint64_t param, bool fast) > { > uint64_t ret; >
On Wed, Feb 07, 2018 at 12:01:41PM +0100, Paolo Bonzini wrote: > On 06/02/2018 21:30, Roman Kagan wrote: > > When setting up a notifier for Hyper-V event connection, attempt to use > > the KVM-assisted one first, and fall back to userspace handling of the > > hypercall if the kernel doesn't provide the requested feature. > > > > Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> > > As before, I wouldn't mind dropping userspace SIGNAL_EVENT altogether. That would mean not allowing vmbus stuff on a range of otherwise usable kernels, including 4.14 which AFAIK has been declared LTS. Note that HYPERV_EVENTFD hasn't even landed in the mainline kernel yet (with any luck it'll make 4.16). > It would probably end up in bitrot. Like every compatibilty code... Thanks, Roman.
On 07/02/2018 20:19, Roman Kagan wrote: >> As before, I wouldn't mind dropping userspace SIGNAL_EVENT altogether. > That would mean not allowing vmbus stuff on a range of otherwise usable > kernels, including 4.14 which AFAIK has been declared LTS. > Note that HYPERV_EVENTFD hasn't even landed in the mainline kernel yet > (with any luck it'll make 4.16). Fair enough. Paolo
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index bbf12a1723..70ad0a54b7 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -496,6 +496,7 @@ void kvm_irqchip_set_qemuirq_gsi(KVMState *s, qemu_irq irq, int gsi); void kvm_pc_gsi_handler(void *opaque, int n, int level); void kvm_pc_setup_irq_routing(bool pci_enabled); void kvm_init_irq_routing(KVMState *s); +int kvm_set_hv_event_notifier(KVMState *s, uint32_t conn_id, EventNotifier *n); /** * kvm_arch_irqchip_create: diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index f290f487a5..c3ba87b701 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -1423,6 +1423,21 @@ static void kvm_irqchip_create(MachineState *machine, KVMState *s) s->gsimap = g_hash_table_new(g_direct_hash, g_direct_equal); } +int kvm_set_hv_event_notifier(KVMState *s, uint32_t conn_id, EventNotifier *n) +{ + struct kvm_hyperv_eventfd hvevfd = { + .conn_id = conn_id, + .fd = n ? event_notifier_get_fd(n) : -1, + .flags = n ? 0 : KVM_HYPERV_EVENTFD_DEASSIGN, + }; + + if (!kvm_check_extension(s, KVM_CAP_HYPERV_EVENTFD)) { + return -ENOSYS; + } + + return kvm_vm_ioctl(s, KVM_HYPERV_EVENTFD, &hvevfd); +} + /* Find number of supported CPUs using the recommended * procedure from the kernel API documentation to cope with * older kernels that may be missing capabilities. diff --git a/target/i386/hyperv.c b/target/i386/hyperv.c index e43cbb9322..63dcb23fa8 100644 --- a/target/i386/hyperv.c +++ b/target/i386/hyperv.c @@ -313,7 +313,8 @@ unlock: return ret; } -int hyperv_set_evt_notifier(uint32_t conn_id, EventNotifier *notifier) +static int hyperv_set_evt_notifier_userspace(uint32_t conn_id, + EventNotifier *notifier) { int ret; EvtHandler *eh; @@ -346,6 +347,24 @@ unlock: return ret; } +static bool hv_evt_notifier_userspace; + +int hyperv_set_evt_notifier(uint32_t conn_id, EventNotifier *notifier) +{ + if (!hv_evt_notifier_userspace) { + int ret = kvm_set_hv_event_notifier(kvm_state, conn_id, notifier); + if (ret != -ENOSYS) { + return ret; + } + + hv_evt_notifier_userspace = true; + warn_report("Hyper-V event signaling in KVM not supported; " + "using slower userspace hypercall processing"); + } + + return hyperv_set_evt_notifier_userspace(conn_id, notifier); +} + static uint64_t hvcall_post_message(uint64_t param, bool fast) { uint64_t ret;
When setting up a notifier for Hyper-V event connection, attempt to use the KVM-assisted one first, and fall back to userspace handling of the hypercall if the kernel doesn't provide the requested feature. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> --- include/sysemu/kvm.h | 1 + accel/kvm/kvm-all.c | 15 +++++++++++++++ target/i386/hyperv.c | 21 ++++++++++++++++++++- 3 files changed, 36 insertions(+), 1 deletion(-)