>
>>
>> I am hoping to see your v9 soon and thereafter maintainer(s) may
choose to
>> pick the latest independent patch if needs to be merged earlier.
>
>
> I don’t think you are understanding what problem it is causing. For
> your small bug fix you are causing significant delays at our end.
>
I hope I clarfied above that including your patch here doesnt delay anything.
Hoping to see your v9 soon!
Thanks
Harsh
>
> Thanks
> Salil.
>>
>> Thanks for your work and let's be hopeful it gets merged soon.
>>
>> regards,
>> Harsh
>>
>> On 5/16/24 14:00, Salil Mehta wrote:
>> > Hi Harsh,
>> >
>> > Thanks for your interest in the patch-set but taking away patches like
>> > this from other series without any discussion can disrupt others work
>> > and its acceptance on time. This is because we will have to put lot of
>> > effort in rebasing bigger series and then testing overhead comes
along
>> > with it.
>> >
>> > The patch-set (from where this patch has been taken) is part of even
>> > bigger series and there have been many people and companies toiling
to
>> > fix the bugs collectively in that series and for years.
>> >
>> > I'm about float the V9 version of the Arch agnostic series which this
>> > patch is part of and you can rebase your patch-set from there. I'm
>> > hopeful that it will get accepted in this cycle.
>> >
>> >
>> > Many thanks
>> > Salil.
>> >
>> >> From: Harsh Prateek Bora <harshpb@linux.ibm.com>
>> >> Sent: Thursday, May 16, 2024 6:32 AM
>> >>
>> >> From: Salil Mehta <salil.mehta@huawei.com>
>> >>
>> >> KVM vCPU creation is done once during the vCPU realization when
>> Qemu
>> >> vCPU thread is spawned. This is common to all the architectures as
of
>> now.
>> >>
>> >> Hot-unplug of vCPU results in destruction of the vCPU object in
QOM
>> but
>> >> the corresponding KVM vCPU object in the Host KVM is not
destroyed
>> as
>> >> KVM doesn't support vCPU removal. Therefore, its representative
KVM
>> >> vCPU object/context in Qemu is parked.
>> >>
>> >> Refactor architecture common logic so that some APIs could be
reused
>> by
>> >> vCPU Hotplug code of some architectures likes ARM, Loongson etc.
>> Update
>> >> new/old APIs with trace events instead of DPRINTF. No functional
>> change is
>> >> intended here.
>> >>
>> >> Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
>> >> Reviewed-by: Gavin Shan <gshan@redhat.com>
>> >> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
>> >> Reviewed-by: Jonathan Cameron
<Jonathan.Cameron@huawei.com>
>> >> Tested-by: Xianglai Li <lixianglai@loongson.cn>
>> >> Tested-by: Miguel Luis <miguel.luis@oracle.com>
>> >> Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
>> >> [harshpb: fixed rebase failures in include/sysemu/kvm.h]
>> >> Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
>> >> ---
>> >> include/sysemu/kvm.h | 15 ++++++++++
>> >> accel/kvm/kvm-all.c | 64
++++++++++++++++++++++++++++++++---
>> -----
>> >> --
>> >> accel/kvm/trace-events | 5 +++-
>> >> 3 files changed, 68 insertions(+), 16 deletions(-)
>> >>
>> >> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index
>> >> eaf801bc93..fa3ec74442 100644
>> >> --- a/include/sysemu/kvm.h
>> >> +++ b/include/sysemu/kvm.h
>> >> @@ -434,6 +434,21 @@ void kvm_set_sigmask_len(KVMState *s,
>> unsigned
>> >> int sigmask_len);
>> >>
>> >> int kvm_physical_memory_addr_from_host(KVMState *s, void
>> >> *ram_addr,
>> >> hwaddr *phys_addr);
>> >> +/**
>> >> + * kvm_create_vcpu - Gets a parked KVM vCPU or creates a KVM
>> vCPU
>> >> + * @cpu: QOM CPUState object for which KVM vCPU has to be
>> >> fetched/created.
>> >> + *
>> >> + * @returns: 0 when success, errno (<0) when failed.
>> >> + */
>> >> +int kvm_create_vcpu(CPUState *cpu);
>> >> +
>> >> +/**
>> >> + * kvm_park_vcpu - Park QEMU KVM vCPU context
>> >> + * @cpu: QOM CPUState object for which QEMU KVM vCPU
context
>> has to
>> >> be parked.
>> >> + *
>> >> + * @returns: none
>> >> + */
>> >> +void kvm_park_vcpu(CPUState *cpu);
>> >>
>> >> #endif /* COMPILING_PER_TARGET */
>> >>
>> >> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index
>> >> d7281b93f3..30d42847de 100644
>> >> --- a/accel/kvm/kvm-all.c
>> >> +++ b/accel/kvm/kvm-all.c
>> >> @@ -128,6 +128,7 @@ static QemuMutex kml_slots_lock; #define
>> >> kvm_slots_unlock() qemu_mutex_unlock(&kml_slots_lock)
>> >>
>> >> static void kvm_slot_init_dirty_bitmap(KVMSlot *mem);
>> >> +static int kvm_get_vcpu(KVMState *s, unsigned long vcpu_id);
>> >>
>> >> static inline void kvm_resample_fd_remove(int gsi) { @@ -340,14
>> +341,53
>> >> @@ err:
>> >> return ret;
>> >> }
>> >>
>> >> +void kvm_park_vcpu(CPUState *cpu)
>> >> +{
>> >> + struct KVMParkedVcpu *vcpu;
>> >> +
>> >> + trace_kvm_park_vcpu(cpu->cpu_index,
kvm_arch_vcpu_id(cpu));
>> >> +
>> >> + vcpu = g_malloc0(sizeof(*vcpu));
>> >> + vcpu->vcpu_id = kvm_arch_vcpu_id(cpu);
>> >> + vcpu->kvm_fd = cpu->kvm_fd;
>> >> + QLIST_INSERT_HEAD(&kvm_state->kvm_parked_vcpus, vcpu,
>> node); }
>> >> +
>> >> +int kvm_create_vcpu(CPUState *cpu)
>> >> +{
>> >> + unsigned long vcpu_id = kvm_arch_vcpu_id(cpu);
>> >> + KVMState *s = kvm_state;
>> >> + int kvm_fd;
>> >> +
>> >> + trace_kvm_create_vcpu(cpu->cpu_index,
kvm_arch_vcpu_id(cpu));
>> >> +
>> >> + /* check if the KVM vCPU already exist but is parked */
>> >> + kvm_fd = kvm_get_vcpu(s, vcpu_id);
>> >> + if (kvm_fd < 0) {
>> >> + /* vCPU not parked: create a new KVM vCPU */
>> >> + kvm_fd = kvm_vm_ioctl(s, KVM_CREATE_VCPU, vcpu_id);
>> >> + if (kvm_fd < 0) {
>> >> + error_report("KVM_CREATE_VCPU IOCTL failed for vCPU
%lu",
>> >> vcpu_id);
>> >> + return kvm_fd;
>> >> + }
>> >> + }
>> >> +
>> >> + cpu->kvm_fd = kvm_fd;
>> >> + cpu->kvm_state = s;
>> >> + cpu->vcpu_dirty = true;
>> >> + cpu->dirty_pages = 0;
>> >> + cpu->throttle_us_per_full = 0;
>> >> +
>> >> + return 0;
>> >> +}
>> >> +
>> >> static int do_kvm_destroy_vcpu(CPUState *cpu) {
>> >> KVMState *s = kvm_state;
>> >> long mmap_size;
>> >> - struct KVMParkedVcpu *vcpu = NULL;
>> >> int ret = 0;
>> >>
>> >> - trace_kvm_destroy_vcpu();
>> >> + trace_kvm_destroy_vcpu(cpu->cpu_index,
>> kvm_arch_vcpu_id(cpu));
>> >>
>> >> ret = kvm_arch_destroy_vcpu(cpu);
>> >> if (ret < 0) {
>> >> @@ -373,10 +413,7 @@ static int do_kvm_destroy_vcpu(CPUState
>> *cpu)
>> >> }
>> >> }
>> >>
>> >> - vcpu = g_malloc0(sizeof(*vcpu));
>> >> - vcpu->vcpu_id = kvm_arch_vcpu_id(cpu);
>> >> - vcpu->kvm_fd = cpu->kvm_fd;
>> >> - QLIST_INSERT_HEAD(&kvm_state->kvm_parked_vcpus, vcpu,
>> node);
>> >> + kvm_park_vcpu(cpu);
>> >> err:
>> >> return ret;
>> >> }
>> >> @@ -397,6 +434,8 @@ static int kvm_get_vcpu(KVMState *s,
unsigned
>> long
>> >> vcpu_id)
>> >> if (cpu->vcpu_id == vcpu_id) {
>> >> int kvm_fd;
>> >>
>> >> + trace_kvm_get_vcpu(vcpu_id);
>> >> +
>> >> QLIST_REMOVE(cpu, node);
>> >> kvm_fd = cpu->kvm_fd;
>> >> g_free(cpu);
>> >> @@ -404,7 +443,7 @@ static int kvm_get_vcpu(KVMState *s,
unsigned
>> long
>> >> vcpu_id)
>> >> }
>> >> }
>> >>
>> >> - return kvm_vm_ioctl(s, KVM_CREATE_VCPU, (void *)vcpu_id);
>> >> + return -ENOENT;
>> >> }
>> >>
>> >> int kvm_init_vcpu(CPUState *cpu, Error **errp) @@ -415,19
+454,14
>> @@
>> >> int kvm_init_vcpu(CPUState *cpu, Error **errp)
>> >>
>> >> trace_kvm_init_vcpu(cpu->cpu_index, kvm_arch_vcpu_id(cpu));
>> >>
>> >> - ret = kvm_get_vcpu(s, kvm_arch_vcpu_id(cpu));
>> >> + ret = kvm_create_vcpu(cpu);
>> >> if (ret < 0) {
>> >> - error_setg_errno(errp, -ret, "kvm_init_vcpu: kvm_get_vcpu
failed
>> >> (%lu)",
>> >> + error_setg_errno(errp, -ret,
>> >> + "kvm_init_vcpu: kvm_create_vcpu failed
(%lu)",
>> >> kvm_arch_vcpu_id(cpu));
>> >> goto err;
>> >> }
>> >>
>> >> - cpu->kvm_fd = ret;
>> >> - cpu->kvm_state = s;
>> >> - cpu->vcpu_dirty = true;
>> >> - cpu->dirty_pages = 0;
>> >> - cpu->throttle_us_per_full = 0;
>> >> -
>> >> mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
>> >> if (mmap_size < 0) {
>> >> ret = mmap_size;
>> >> diff --git a/accel/kvm/trace-events b/accel/kvm/trace-events index
>> >> 681ccb667d..75c1724e78 100644
>> >> --- a/accel/kvm/trace-events
>> >> +++ b/accel/kvm/trace-events
>> >> @@ -9,6 +9,10 @@ kvm_device_ioctl(int fd, int type, void *arg)
"dev fd
>> %d,
>> >> type 0x%x, arg %p"
>> >> kvm_failed_reg_get(uint64_t id, const char *msg) "Warning:
Unable to
>> >> retrieve ONEREG %" PRIu64 " from KVM: %s"
>> >> kvm_failed_reg_set(uint64_t id, const char *msg) "Warning:
Unable to
>> set
>> >> ONEREG %" PRIu64 " to KVM: %s"
>> >> kvm_init_vcpu(int cpu_index, unsigned long arch_cpu_id) "index:
%d
>> id:
>> >> %lu"
>> >> +kvm_create_vcpu(int cpu_index, unsigned long arch_cpu_id)
"index:
>> %d
>> >> id: %lu"
>> >> +kvm_get_vcpu(unsigned long arch_cpu_id) "id: %lu"
>> >> +kvm_destroy_vcpu(int cpu_index, unsigned long arch_cpu_id)
"index:
>> %d
>> >> id: %lu"
>> >> +kvm_park_vcpu(int cpu_index, unsigned long arch_cpu_id)
"index: %d
>> id:
>> >> %lu"
>> >> kvm_irqchip_commit_routes(void) ""
>> >> kvm_irqchip_add_msi_route(char *name, int vector, int virq) "dev
%s
>> >> vector %d virq %d"
>> >> kvm_irqchip_update_msi_route(int virq) "Updating MSI route
>> virq=%d"
>> >> @@ -25,7 +29,6 @@ kvm_dirty_ring_reaper(const char *s) "%s"
>> >> kvm_dirty_ring_reap(uint64_t count, int64_t t) "reaped %"PRIu64"
>> pages
>> >> (took %"PRIi64" us)"
>> >> kvm_dirty_ring_reaper_kick(const char *reason) "%s"
>> >> kvm_dirty_ring_flush(int finished) "%d"
>> >> -kvm_destroy_vcpu(void) ""
>> >> kvm_failed_get_vcpu_mmap_size(void) ""
>> >> kvm_cpu_exec(void) ""
>> >> kvm_interrupt_exit_request(void) ""
>> >> --
>> >> 2.39.3
>> >