From patchwork Tue Sep 26 10:04:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Salil Mehta X-Patchwork-Id: 13398997 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 31DF6E7D273 for ; Tue, 26 Sep 2023 10:07:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ql4yR-00065t-R3; Tue, 26 Sep 2023 06:07:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ql4y8-0005fF-Cd; Tue, 26 Sep 2023 06:07:04 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ql4y6-00046B-Kn; Tue, 26 Sep 2023 06:07:04 -0400 Received: from lhrpeml500001.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4RvwNp2tLnz6K8sk; Tue, 26 Sep 2023 18:05:46 +0800 (CST) Received: from A190218597.china.huawei.com (10.126.174.16) by lhrpeml500001.china.huawei.com (7.191.163.213) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 26 Sep 2023 11:06:42 +0100 To: , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH RFC V2 05/37] accel/kvm: Extract common KVM vCPU {creation, parking} code Date: Tue, 26 Sep 2023 11:04:04 +0100 Message-ID: <20230926100436.28284-6-salil.mehta@huawei.com> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20230926100436.28284-1-salil.mehta@huawei.com> References: <20230926100436.28284-1-salil.mehta@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.126.174.16] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To lhrpeml500001.china.huawei.com (7.191.163.213) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=185.176.79.56; envelope-from=salil.mehta@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Salil Mehta X-Patchwork-Original-From: Salil Mehta via From: Salil Mehta Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org KVM vCPU creation is done once during the initialization of the VM when Qemu threads are spawned. This is common to all the architectures. If the architecture supports vCPU hot-{un}plug then this KVM vCPU creation could be deferred to later point as well. Some architectures might in any case create KVM vCPUs for the yet-to-be plugged vCPUs (i.e. QoM Object & thread does not exists) during VM init time and park them. Hot-unplug of vCPU results in destruction of the vCPU objects in QOM but the KVM vCPU objects in the Host KVM are not destroyed and their representative KVM vCPU objects in Qemu are parked. Signed-off-by: Salil Mehta --- accel/kvm/kvm-all.c | 61 ++++++++++++++++++++++++++++++++++---------- include/sysemu/kvm.h | 2 ++ 2 files changed, 49 insertions(+), 14 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 7b3da8dc3a..86e9c9ea60 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) { @@ -320,11 +321,51 @@ err: return ret; } +void kvm_park_vcpu(CPUState *cpu) +{ + unsigned long vcpu_id = cpu->cpu_index; + struct KVMParkedVcpu *vcpu; + + vcpu = g_malloc0(sizeof(*vcpu)); + vcpu->vcpu_id = vcpu_id; + 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 = cpu->cpu_index; + KVMState *s = kvm_state; + int ret; + + DPRINTF("kvm_create_vcpu\n"); + + /* check if the KVM vCPU already exist but is parked */ + ret = kvm_get_vcpu(s, kvm_arch_vcpu_id(cpu)); + if (ret > 0) { + goto found; + } + + /* create a new KVM vcpu */ + ret = kvm_vm_ioctl(s, KVM_CREATE_VCPU, (void *)vcpu_id); + if (ret < 0) { + return ret; + } + +found: + cpu->vcpu_dirty = true; + cpu->kvm_fd = ret; + cpu->kvm_state = s; + 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"); @@ -353,10 +394,7 @@ 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; } @@ -384,7 +422,7 @@ static int kvm_get_vcpu(KVMState *s, unsigned long vcpu_id) } } - return kvm_vm_ioctl(s, KVM_CREATE_VCPU, (void *)vcpu_id); + return -1; } int kvm_init_vcpu(CPUState *cpu, Error **errp) @@ -395,19 +433,14 @@ 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/include/sysemu/kvm.h b/include/sysemu/kvm.h index 115f0cca79..2c34889b01 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -473,6 +473,8 @@ 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); +int kvm_create_vcpu(CPUState *cpu); +void kvm_park_vcpu(CPUState *cpu); #endif /* NEED_CPU_H */