Hi Igor, Thanks for the review comments. I was bit on and off so could not address the comments. Please find my replies inline.
> From: Igor Mammedov <[email protected]> > Sent: Friday, October 27, 2023 1:57 PM > To: Salil Mehta <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; jean- > [email protected]; Jonathan Cameron <[email protected]>; > [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; zhukeqian > <[email protected]>; wangxiongfeng (C) <[email protected]>; > wangyanan (Y) <[email protected]>; [email protected]; > [email protected]; [email protected]; Linuxarm <[email protected]> > Subject: Re: [PATCH V6 1/9] accel/kvm: Extract common KVM vCPU > {creation,parking} code > > On Fri, 13 Oct 2023 11:51:21 +0100 > Salil Mehta <[email protected]> wrote: > > > KVM vCPU creation is done once during the initialization of the VM when Qemu > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > thread is spawned. This is common to all the architectures. > > is it really true fox x86? Thanks for pointing out. I just meant, "KVM vCPU creation is done once either during VM initialization or during vCPU realization during Hotplug...." > > 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 and its > ^ > since KVM doesn't support vCPU removal Correct. Will add. > > representative KVM vCPU object/context in Qemu is parked. > > > > Refactor common logic so that some APIs could be reused by vCPU Hotplug > > code. > 'reused' part doesn't happen within this series. So a reason > why patch exists is not clear/no one can deduce the reason > without the actual user here. > > Suggest to move it to a series that actually will use this patch. I can do that but I think Loongson guys might need bit of this logic as well. This patch also brings a good restructuring to the existing code and fixes the traces etc. I would humbly suggest to keep it unless you have strong views. Thanks Salil. > > Update new/old APIs with trace events instead of DTRACE. > > > > Signed-off-by: Salil Mehta <[email protected]> > > Reviewed-by: Gavin Shan <[email protected]> > > Tested-by: Vishnu Pajjuri <[email protected]> > > Reviewed-by: Jonathan Cameron <[email protected]> > > Tested-by: Xianglai Li <[email protected]> > > --- > > accel/kvm/kvm-all.c | 64 ++++++++++++++++++++++++++++++++---------- > > accel/kvm/trace-events | 4 +++ > > include/sysemu/kvm.h | 16 +++++++++++ > > 3 files changed, 69 insertions(+), 15 deletions(-) > > > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > > index 72e1d1141c..bfa7816aaa 100644 > > --- a/accel/kvm/kvm-all.c > > +++ b/accel/kvm/kvm-all.c > > @@ -137,6 +137,7 @@ 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) > > { > > @@ -320,14 +321,53 @@ 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; > > > > - DPRINTF("kvm_destroy_vcpu\n"); > > + trace_kvm_destroy_vcpu(cpu->cpu_index, kvm_arch_vcpu_id(cpu)); > > > > ret = kvm_arch_destroy_vcpu(cpu); > > if (ret < 0) { > > @@ -353,10 +393,7 @@ 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; > > } > > @@ -377,6 +414,8 @@ 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); > > @@ -384,7 +423,7 @@ 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) > > @@ -395,19 +434,14 @@ 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 399aaeb0ec..cdd0c95c09 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" > > diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h > > index ee9025f8e9..8137e6a44c 100644 > > --- a/include/sysemu/kvm.h > > +++ b/include/sysemu/kvm.h > > @@ -465,6 +465,22 @@ 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 /* NEED_CPU_H */ > > > > void kvm_cpu_synchronize_state(CPUState *cpu);
