From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f73.google.com (mail-wr1-f73.google.com [209.85.221.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A90C3D79F0 for ; Fri, 12 Jun 2026 06:59:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781247578; cv=none; b=GN2qdIULHEQIzBnaTlag+J5qJSotKPmuCSSJARvMgmuRUo0V7OBBkhrSwruJ1lDUuDHwgNdMYhdGz0fR9cOOCvAzYcMM9mZ9J0nPlJgK1RTEs2zEN3/JydAfnMaVcVu+iXNScBFDlH1SC4XRILWq/uWHRtBw2BEAXe7+HIkvoQs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781247578; c=relaxed/simple; bh=jx/Yhq70Bsl7Q9oV5QijYVYxWzGtpUh9z9eIo/RbLoo=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=SYE3X1ZJAgsCUvBt/2vkYj4PyMB5yUgKORV1HR5+N6Szp0i46h7kdD5G+Cxr7e+EQQtyKRIcael9PO0rcbsU8skcqD2RIO1QSFVYddkuqbTVXo6xRIbBl0LYoL7Uqr3QD9KTZ5qHxJIMrrDR6ohgZFnei5GR/MOlxHbYFuSKBhw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tabba.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=dkfYufsO; arc=none smtp.client-ip=209.85.221.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tabba.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="dkfYufsO" Received: by mail-wr1-f73.google.com with SMTP id ffacd0b85a97d-45ef55779d1so416108f8f.0 for ; Thu, 11 Jun 2026 23:59:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781247570; x=1781852370; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=xaz60O81ceKnaW6fsPnXrD/MZKDxDO1Yi/KW97lEVIQ=; b=dkfYufsOMwUQjKXDBLgSDWezSPVDvG0MJIGItDWX7AB55UOvWNm+LdQK9TudW+eESq s2UYFucERbXtkSKenedYnuMV8/L1V8tN1gMMevJXk4hedCXVMeeNVoieMHiHxllrz09n rvM+zDl0nJVO4G1geXpWfHSmj8TtYyuBd3HBPgI2n0PBE/Q2CINbuKepdt/1WrE1PEFK 7n9LFYFfo9J8doEC1cpsihoTb+AULebMqhDgE2xI3k1LMJM0SHSwSK4blxNsmZoawDqz a3Um2uuusfuf9KBgYU5DpNp21ve9eFFQ7jrBw834VJEbK3Izuk0fbxNM/GFxOEe6Gib0 2cBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781247570; x=1781852370; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=xaz60O81ceKnaW6fsPnXrD/MZKDxDO1Yi/KW97lEVIQ=; b=VM/NitGWRINCapcaX43+7of92nCc1HXeaNomZRHlR8soQ1d6sHncNGcen+8kK89qnw FN04w2K767kRx7qf91i+HeHtYK5N4GGF+7U2axtkaU3gEC3wGTGaHHyXg3i1I2mnl4k4 JgN4J47NwOZZXyubtNLtGI1z4hzU7Lszz9TEq0VYzjhyCCr7wAulOFQOMnQ1bcgU03Cq e2A/qB8uP+bxXCxGEBVLtQPj0EO//DqvwWVQQPCYKWoTk2HO5rkfvPtfv0K4g5inCscQ JWutEKVjNdGYIWGk6+ooBijEjpLx/wEyUdZandd8I82dTGP/PwjHrVRBjd1A7xVXfvlq MXEw== X-Forwarded-Encrypted: i=1; AFNElJ9Aq1H/mPjF42t9yMO/2Lvd6Y+kxwX0xO6bqEOxfM1cPQZzoyO5AoGsWY/A+AmrC5BYplbH1B4=@lists.linux.dev X-Gm-Message-State: AOJu0Yz8Mfl01EwKe4oyRVQaYFO+jhdZ4sXgwk2IcJ80g6Yr1+PKgQfe QpPrOCjXjya3UQg2NSZdVzqPNUEkTW5gYh61Ryi/8CCcdXGuQdelcQcHlnNDVo3SSQXCeBRGFOD BUg== X-Received: from wmxb3-n2.prod.google.com ([2002:a05:600d:8443:20b0:490:bfa7:ad27]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:c3cd:20b0:490:d3ef:fa4a with SMTP id 5b1f17b1804b1-490ec4ea4f1mr10709515e9.14.1781247569549; Thu, 11 Jun 2026 23:59:29 -0700 (PDT) Date: Fri, 12 Jun 2026 07:59:17 +0100 In-Reply-To: <20260612065925.755562-1-tabba@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260612065925.755562-1-tabba@google.com> X-Mailer: git-send-email 2.54.0.1136.gdb2ca164c4-goog Message-ID: <20260612065925.755562-4-tabba@google.com> Subject: [PATCH v1 03/11] KVM: arm64: Use guard()/scoped_guard() in arm64 KVM EL1 code From: tabba@google.com To: Marc Zyngier , Oliver Upton Cc: Fuad Tabba , Will Deacon , Catalin Marinas , Quentin Perret , Vincent Donnefort , Sebastian Ene , Per Larsen , Suzuki K Poulose , Zenghui Yu , Joey Gouly , Steffen Eiden , Mark Rutland , Jonathan Cameron , Hyunwoo Kim , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Convert the manual mutex_lock()/spin_lock() pairs in arch/arm64/kvm/{pkvm,arm,mmu,reset,psci}.c to guard(mutex), guard(spinlock) and scoped_guard(), dropping unlock-only goto labels in favour of direct returns. Centralised cleanup gotos that still serve other resources are preserved. reset.c uses scoped_guard() rather than guard() so the lock covers only the small read/update window inside kvm_reset_vcpu(), leaving the rest of the function outside the critical section. Signed-off-by: Fuad Tabba --- arch/arm64/kvm/arm.c | 14 +++----- arch/arm64/kvm/mmu.c | 80 +++++++++++++++--------------------------- arch/arm64/kvm/pkvm.c | 26 ++++++-------- arch/arm64/kvm/psci.c | 17 ++++----- arch/arm64/kvm/reset.c | 8 ++--- 5 files changed, 53 insertions(+), 92 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9453321ef8c6..c9f36932c980 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -793,9 +793,7 @@ int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { - int ret = 0; - - spin_lock(&vcpu->arch.mp_state_lock); + guard(spinlock)(&vcpu->arch.mp_state_lock); switch (mp_state->mp_state) { case KVM_MP_STATE_RUNNABLE: @@ -808,12 +806,10 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, kvm_arm_vcpu_suspend(vcpu); break; default: - ret = -EINVAL; + return -EINVAL; } - spin_unlock(&vcpu->arch.mp_state_lock); - - return ret; + return 0; } /** @@ -1726,15 +1722,13 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, /* * Handle the "start in power-off" case. */ - spin_lock(&vcpu->arch.mp_state_lock); + guard(spinlock)(&vcpu->arch.mp_state_lock); if (power_off) __kvm_arm_vcpu_power_off(vcpu); else WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE); - spin_unlock(&vcpu->arch.mp_state_lock); - return 0; } diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 4da9281312eb..d18f4ce7ceae 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -391,13 +391,13 @@ static void stage2_flush_vm(struct kvm *kvm) */ void __init free_hyp_pgds(void) { - mutex_lock(&kvm_hyp_pgd_mutex); - if (hyp_pgtable) { - kvm_pgtable_hyp_destroy(hyp_pgtable); - kfree(hyp_pgtable); - hyp_pgtable = NULL; - } - mutex_unlock(&kvm_hyp_pgd_mutex); + guard(mutex)(&kvm_hyp_pgd_mutex); + if (!hyp_pgtable) + return; + + kvm_pgtable_hyp_destroy(hyp_pgtable); + kfree(hyp_pgtable); + hyp_pgtable = NULL; } static bool kvm_host_owns_hyp_mappings(void) @@ -424,16 +424,11 @@ static bool kvm_host_owns_hyp_mappings(void) int __create_hyp_mappings(unsigned long start, unsigned long size, unsigned long phys, enum kvm_pgtable_prot prot) { - int err; - if (WARN_ON(!kvm_host_owns_hyp_mappings())) return -EINVAL; - mutex_lock(&kvm_hyp_pgd_mutex); - err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot); - mutex_unlock(&kvm_hyp_pgd_mutex); - - return err; + guard(mutex)(&kvm_hyp_pgd_mutex); + return kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot); } static phys_addr_t kvm_kaddr_to_phys(void *kaddr) @@ -481,56 +476,42 @@ static int share_pfn_hyp(u64 pfn) { struct rb_node **node, *parent; struct hyp_shared_pfn *this; - int ret = 0; - mutex_lock(&hyp_shared_pfns_lock); + guard(mutex)(&hyp_shared_pfns_lock); this = find_shared_pfn(pfn, &node, &parent); if (this) { this->count++; - goto unlock; + return 0; } this = kzalloc_obj(*this); - if (!this) { - ret = -ENOMEM; - goto unlock; - } + if (!this) + return -ENOMEM; this->pfn = pfn; this->count = 1; rb_link_node(&this->node, parent, node); rb_insert_color(&this->node, &hyp_shared_pfns); - ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn); -unlock: - mutex_unlock(&hyp_shared_pfns_lock); - - return ret; + return kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn); } static int unshare_pfn_hyp(u64 pfn) { struct rb_node **node, *parent; struct hyp_shared_pfn *this; - int ret = 0; - mutex_lock(&hyp_shared_pfns_lock); + guard(mutex)(&hyp_shared_pfns_lock); this = find_shared_pfn(pfn, &node, &parent); - if (WARN_ON(!this)) { - ret = -ENOENT; - goto unlock; - } + if (WARN_ON(!this)) + return -ENOENT; this->count--; if (this->count) - goto unlock; + return 0; rb_erase(&this->node, &hyp_shared_pfns); kfree(this); - ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn); -unlock: - mutex_unlock(&hyp_shared_pfns_lock); - - return ret; + return kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn); } int kvm_share_hyp(void *from, void *to) @@ -655,7 +636,7 @@ int hyp_alloc_private_va_range(size_t size, unsigned long *haddr) unsigned long base; int ret = 0; - mutex_lock(&kvm_hyp_pgd_mutex); + guard(mutex)(&kvm_hyp_pgd_mutex); /* * This assumes that we have enough space below the idmap @@ -670,8 +651,6 @@ int hyp_alloc_private_va_range(size_t size, unsigned long *haddr) base = io_map_base - size; ret = __hyp_alloc_private_va_range(base); - mutex_unlock(&kvm_hyp_pgd_mutex); - if (!ret) *haddr = base; @@ -714,17 +693,16 @@ int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr) size_t size; int ret; - mutex_lock(&kvm_hyp_pgd_mutex); - /* - * Efficient stack verification using the NVHE_STACK_SHIFT bit implies - * an alignment of our allocation on the order of the size. - */ - size = NVHE_STACK_SIZE * 2; - base = ALIGN_DOWN(io_map_base - size, size); + scoped_guard(mutex, &kvm_hyp_pgd_mutex) { + /* + * Efficient stack verification using the NVHE_STACK_SHIFT bit implies + * an alignment of our allocation on the order of the size. + */ + size = NVHE_STACK_SIZE * 2; + base = ALIGN_DOWN(io_map_base - size, size); - ret = __hyp_alloc_private_va_range(base); - - mutex_unlock(&kvm_hyp_pgd_mutex); + ret = __hyp_alloc_private_va_range(base); + } if (ret) { kvm_err("Cannot allocate hyp stack guard page\n"); diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index 053e4f733e4b..a39111b70f9f 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -190,39 +190,33 @@ bool pkvm_hyp_vm_is_created(struct kvm *kvm) int pkvm_create_hyp_vm(struct kvm *kvm) { - int ret = 0; - /* * Synchronise with kvm_arch_prepare_memory_region(), as we * prevent memslot modifications on a pVM that has been run. */ - mutex_lock(&kvm->slots_lock); - mutex_lock(&kvm->arch.config_lock); - if (!pkvm_hyp_vm_is_created(kvm)) - ret = __pkvm_create_hyp_vm(kvm); - mutex_unlock(&kvm->arch.config_lock); - mutex_unlock(&kvm->slots_lock); + guard(mutex)(&kvm->slots_lock); + guard(mutex)(&kvm->arch.config_lock); - return ret; + if (!pkvm_hyp_vm_is_created(kvm)) + return __pkvm_create_hyp_vm(kvm); + + return 0; } int pkvm_create_hyp_vcpu(struct kvm_vcpu *vcpu) { - int ret = 0; + guard(mutex)(&vcpu->kvm->arch.config_lock); - mutex_lock(&vcpu->kvm->arch.config_lock); if (!vcpu_get_flag(vcpu, VCPU_PKVM_FINALIZED)) - ret = __pkvm_create_hyp_vcpu(vcpu); - mutex_unlock(&vcpu->kvm->arch.config_lock); + return __pkvm_create_hyp_vcpu(vcpu); - return ret; + return 0; } void pkvm_destroy_hyp_vm(struct kvm *kvm) { - mutex_lock(&kvm->arch.config_lock); + guard(mutex)(&kvm->arch.config_lock); __pkvm_destroy_hyp_vm(kvm); - mutex_unlock(&kvm->arch.config_lock); } int pkvm_init_host_vm(struct kvm *kvm, unsigned long type) diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 3b5dbe9a0a0e..e1389c525e9d 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -62,7 +62,6 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) struct vcpu_reset_state *reset_state; struct kvm *kvm = source_vcpu->kvm; struct kvm_vcpu *vcpu = NULL; - int ret = PSCI_RET_SUCCESS; unsigned long cpu_id; cpu_id = smccc_get_arg1(source_vcpu); @@ -78,14 +77,13 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) if (!vcpu) return PSCI_RET_INVALID_PARAMS; - spin_lock(&vcpu->arch.mp_state_lock); + guard(spinlock)(&vcpu->arch.mp_state_lock); + if (!kvm_arm_vcpu_stopped(vcpu)) { if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) - ret = PSCI_RET_ALREADY_ON; + return PSCI_RET_ALREADY_ON; else - ret = PSCI_RET_INVALID_PARAMS; - - goto out_unlock; + return PSCI_RET_INVALID_PARAMS; } reset_state = &vcpu->arch.reset_state; @@ -113,9 +111,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE); kvm_vcpu_wake_up(vcpu); -out_unlock: - spin_unlock(&vcpu->arch.mp_state_lock); - return ret; + return PSCI_RET_SUCCESS; } static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) @@ -176,9 +172,8 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type, u64 flags) * re-initialized. */ kvm_for_each_vcpu(i, tmp, vcpu->kvm) { - spin_lock(&tmp->arch.mp_state_lock); + guard(spinlock)(&tmp->arch.mp_state_lock); WRITE_ONCE(tmp->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED); - spin_unlock(&tmp->arch.mp_state_lock); } kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP); diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index b963fd975aac..60969d90bdd3 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -193,10 +193,10 @@ void kvm_reset_vcpu(struct kvm_vcpu *vcpu) bool loaded; u32 pstate; - spin_lock(&vcpu->arch.mp_state_lock); - reset_state = vcpu->arch.reset_state; - vcpu->arch.reset_state.reset = false; - spin_unlock(&vcpu->arch.mp_state_lock); + scoped_guard(spinlock, &vcpu->arch.mp_state_lock) { + reset_state = vcpu->arch.reset_state; + vcpu->arch.reset_state.reset = false; + } preempt_disable(); loaded = (vcpu->cpu != -1); -- 2.54.0.1136.gdb2ca164c4-goog