From patchwork Wed Apr 9 01:41:35 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 14043965 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8968918A92D for ; Wed, 9 Apr 2025 01:42:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744162937; cv=none; b=ZMzZrT/oT55QhZfKs2UeNkaWnvd9JiM+ncG80XwDjygpu6dnjXGUZXDX4sRIqOv0smk7CO9QGNaVyNA2AMFiegm3Rz4uyi7yxzgKdaC0P5/VNfxUiy3Gr6fhkoMyNr9SCviVUB0zUDCuKlwuati82o+dEsMbP31du5eXWjVBdJg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744162937; c=relaxed/simple; bh=kWMoAZ/6MoptLjZVnborOmzeog9qJPTlM+Akp+Z5jBs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=FUp2F4lvqWE+F0ALEw8u6HMpUAJyXB8PBZAXvxt3652UilC/Drjhab/+5ifBu3gRdoyltRhoqc9H7qRV+3OkCmIxADhW7TZenE3fXjl3uqQGIIb+po3d8G8tNW7FuCOutTzhfqluTH3U0xS4m1JVUlRLKPg21ap3rOjaQ5Q0u44= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Y/2misdF; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Y/2misdF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744162933; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vdWJa1iWuf75Z3WwaZMFwx3loSaLxfrrFv/72IaVBE4=; b=Y/2misdFToaxW0L2Lvuf59DndIcE6X2QXLbSdFtUdOO7tXBVN/HVZW62NJrdeQhk7ZlvZz 5Kd5ctUo0UUZqbHRLZwc9EfZ1+drT8HyITI3ypPS2KuO/CyFlS1UsFy2ni7vrxOvc9aE7o qo4LgU+W0jNBOdiiWkK1EeKSFK/kkvo= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-25-SCjKqFNoPX2Alb788oTNSg-1; Tue, 08 Apr 2025 21:42:08 -0400 X-MC-Unique: SCjKqFNoPX2Alb788oTNSg-1 X-Mimecast-MFC-AGG-ID: SCjKqFNoPX2Alb788oTNSg_1744162925 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A72A0180035E; Wed, 9 Apr 2025 01:42:04 +0000 (UTC) Received: from starship.lan (unknown [10.22.65.191]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id DB6BC180174E; Wed, 9 Apr 2025 01:41:58 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Alexander Potapenko , "H. Peter Anvin" , Suzuki K Poulose , kvm-riscv@lists.infradead.org, Oliver Upton , Dave Hansen , Jing Zhang , Waiman Long , x86@kernel.org, Kunkun Jiang , Boqun Feng , Anup Patel , Albert Ou , kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, Zenghui Yu , Borislav Petkov , Alexandre Ghiti , Keisuke Nishimura , Sebastian Ott , Paolo Bonzini , Atish Patra , Paul Walmsley , Randy Dunlap , Will Deacon , Palmer Dabbelt , linux-riscv@lists.infradead.org, Marc Zyngier , linux-arm-kernel@lists.infradead.org, Joey Gouly , Peter Zijlstra , Ingo Molnar , Andre Przywara , Thomas Gleixner , Sean Christopherson , Catalin Marinas , Maxim Levitsky , Bjorn Helgaas Subject: [PATCH v2 3/4] KVM: arm64: switch to using kvm_lock/unlock_all_vcpus Date: Tue, 8 Apr 2025 21:41:35 -0400 Message-Id: <20250409014136.2816971-4-mlevitsk@redhat.com> In-Reply-To: <20250409014136.2816971-1-mlevitsk@redhat.com> References: <20250409014136.2816971-1-mlevitsk@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Switch to kvm_lock/unlock_all_vcpus instead of arm's own version. This fixes lockdep warning about reaching maximum lock depth: [ 328.171264] BUG: MAX_LOCK_DEPTH too low! [ 328.175227] turning off the locking correctness validator. [ 328.180726] Please attach the output of /proc/lock_stat to the bug report [ 328.187531] depth: 48 max: 48! [ 328.190678] 48 locks held by qemu-kvm/11664: [ 328.194957] #0: ffff800086de5ba0 (&kvm->lock){+.+.}-{3:3}, at: kvm_ioctl_create_device+0x174/0x5b0 [ 328.204048] #1: ffff0800e78800b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.212521] #2: ffff07ffeee51e98 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.220991] #3: ffff0800dc7d80b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.229463] #4: ffff07ffe0c980b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.237934] #5: ffff0800a3883c78 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.246405] #6: ffff07fffbe480b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 Suggested-by: Paolo Bonzini Signed-off-by: Maxim Levitsky --- arch/arm64/include/asm/kvm_host.h | 3 -- arch/arm64/kvm/arch_timer.c | 4 +-- arch/arm64/kvm/arm.c | 43 --------------------------- arch/arm64/kvm/vgic/vgic-init.c | 4 +-- arch/arm64/kvm/vgic/vgic-its.c | 8 ++--- arch/arm64/kvm/vgic/vgic-kvm-device.c | 12 ++++---- 6 files changed, 14 insertions(+), 60 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e98cfe7855a6..96ce0b01a61e 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1263,9 +1263,6 @@ int __init populate_sysreg_config(const struct sys_reg_desc *sr, unsigned int idx); int __init populate_nv_trap_config(void); -bool lock_all_vcpus(struct kvm *kvm); -void unlock_all_vcpus(struct kvm *kvm); - void kvm_calculate_traps(struct kvm_vcpu *vcpu); /* MMIO helpers */ diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 5133dcbfe9f7..1c71ce9a5e73 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -1766,7 +1766,7 @@ int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm, mutex_lock(&kvm->lock); - if (lock_all_vcpus(kvm)) { + if (!kvm_lock_all_vcpus(kvm, true)) { set_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET, &kvm->arch.flags); /* @@ -1778,7 +1778,7 @@ int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm, kvm->arch.timer_data.voffset = offset->counter_offset; kvm->arch.timer_data.poffset = offset->counter_offset; - unlock_all_vcpus(kvm); + kvm_unlock_all_vcpus(kvm); } else { ret = -EBUSY; } diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 68fec8c95fee..d31f42a71bdc 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1914,49 +1914,6 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) } } -/* unlocks vcpus from @vcpu_lock_idx and smaller */ -static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx) -{ - struct kvm_vcpu *tmp_vcpu; - - for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) { - tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx); - mutex_unlock(&tmp_vcpu->mutex); - } -} - -void unlock_all_vcpus(struct kvm *kvm) -{ - lockdep_assert_held(&kvm->lock); - - unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1); -} - -/* Returns true if all vcpus were locked, false otherwise */ -bool lock_all_vcpus(struct kvm *kvm) -{ - struct kvm_vcpu *tmp_vcpu; - unsigned long c; - - lockdep_assert_held(&kvm->lock); - - /* - * Any time a vcpu is in an ioctl (including running), the - * core KVM code tries to grab the vcpu->mutex. - * - * By grabbing the vcpu->mutex of all VCPUs we ensure that no - * other VCPUs can fiddle with the state while we access it. - */ - kvm_for_each_vcpu(c, tmp_vcpu, kvm) { - if (!mutex_trylock(&tmp_vcpu->mutex)) { - unlock_vcpus(kvm, c - 1); - return false; - } - } - - return true; -} - static unsigned long nvhe_percpu_size(void) { return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) - diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index 1f33e71c2a73..8241a57e3f96 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -88,7 +88,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) lockdep_assert_held(&kvm->lock); ret = -EBUSY; - if (!lock_all_vcpus(kvm)) + if (kvm_lock_all_vcpus(kvm, true)) return ret; mutex_lock(&kvm->arch.config_lock); @@ -142,7 +142,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) out_unlock: mutex_unlock(&kvm->arch.config_lock); - unlock_all_vcpus(kvm); + kvm_unlock_all_vcpus(kvm); return ret; } diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index fb96802799c6..a06d554cb8a2 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -1999,7 +1999,7 @@ static int vgic_its_attr_regs_access(struct kvm_device *dev, mutex_lock(&dev->kvm->lock); - if (!lock_all_vcpus(dev->kvm)) { + if (kvm_lock_all_vcpus(dev->kvm, true)) { mutex_unlock(&dev->kvm->lock); return -EBUSY; } @@ -2034,7 +2034,7 @@ static int vgic_its_attr_regs_access(struct kvm_device *dev, } out: mutex_unlock(&dev->kvm->arch.config_lock); - unlock_all_vcpus(dev->kvm); + kvm_unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); return ret; } @@ -2704,7 +2704,7 @@ static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr) mutex_lock(&kvm->lock); - if (!lock_all_vcpus(kvm)) { + if (kvm_lock_all_vcpus(kvm, true)) { mutex_unlock(&kvm->lock); return -EBUSY; } @@ -2726,7 +2726,7 @@ static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr) mutex_unlock(&its->its_lock); mutex_unlock(&kvm->arch.config_lock); - unlock_all_vcpus(kvm); + kvm_unlock_all_vcpus(kvm); mutex_unlock(&kvm->lock); return ret; } diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c index 359094f68c23..232838891464 100644 --- a/arch/arm64/kvm/vgic/vgic-kvm-device.c +++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c @@ -268,7 +268,7 @@ static int vgic_set_common_attr(struct kvm_device *dev, return -ENXIO; mutex_lock(&dev->kvm->lock); - if (!lock_all_vcpus(dev->kvm)) { + if (kvm_lock_all_vcpus(dev->kvm, true)) { mutex_unlock(&dev->kvm->lock); return -EBUSY; } @@ -276,7 +276,7 @@ static int vgic_set_common_attr(struct kvm_device *dev, mutex_lock(&dev->kvm->arch.config_lock); r = vgic_v3_save_pending_tables(dev->kvm); mutex_unlock(&dev->kvm->arch.config_lock); - unlock_all_vcpus(dev->kvm); + kvm_unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); return r; } @@ -390,7 +390,7 @@ static int vgic_v2_attr_regs_access(struct kvm_device *dev, mutex_lock(&dev->kvm->lock); - if (!lock_all_vcpus(dev->kvm)) { + if (kvm_lock_all_vcpus(dev->kvm, true)) { mutex_unlock(&dev->kvm->lock); return -EBUSY; } @@ -415,7 +415,7 @@ static int vgic_v2_attr_regs_access(struct kvm_device *dev, out: mutex_unlock(&dev->kvm->arch.config_lock); - unlock_all_vcpus(dev->kvm); + kvm_unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); if (!ret && !is_write) @@ -554,7 +554,7 @@ static int vgic_v3_attr_regs_access(struct kvm_device *dev, mutex_lock(&dev->kvm->lock); - if (!lock_all_vcpus(dev->kvm)) { + if (kvm_lock_all_vcpus(dev->kvm, true)) { mutex_unlock(&dev->kvm->lock); return -EBUSY; } @@ -611,7 +611,7 @@ static int vgic_v3_attr_regs_access(struct kvm_device *dev, out: mutex_unlock(&dev->kvm->arch.config_lock); - unlock_all_vcpus(dev->kvm); + kvm_unlock_all_vcpus(dev->kvm); mutex_unlock(&dev->kvm->lock); if (!ret && uaccess && !is_write) {