From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1016379C2; Sat, 30 Dec 2023 12:06:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="B+DOPr3B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E516C433C8; Sat, 30 Dec 2023 12:06:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1703938012; bh=8kELQPakE4OMFUzM20IJORanDGKgdHKGUTQxEyF9hxE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B+DOPr3Bo5AL/ie+sbdPrRrTq9wmEFTycMB9G+a0ShrqULbOj4WzKOs0GIuZ9llSt bzTKtniFWcSTi2/s1soPK6muCT2Ze2NJEZZrTJCAfwLkgOXosV63ii71ibmvE2bd/f gR3KN4J5lpF9QgYx5TkyYPyrcUr4yuQIDSG6v9Fo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marc Zyngier , Oliver Upton Subject: [PATCH 6.6 150/156] KVM: arm64: vgic: Simplify kvm_vgic_destroy() Date: Sat, 30 Dec 2023 12:00:04 +0000 Message-ID: <20231230115817.209156889@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231230115812.333117904@linuxfoundation.org> References: <20231230115812.333117904@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit 01ad29d224ff73bc4e16e0ef9ece17f28598c4a4 upstream. When destroying a vgic, we have rather cumbersome rules about when slots_lock and config_lock are held, resulting in fun buglets. The first port of call is to simplify kvm_vgic_map_resources() so that there is only one call to kvm_vgic_destroy() instead of two, with the second only holding half of the locks. For that, we kill the non-locking primitive and move the call outside of the locking altogether. This doesn't change anything (we re-acquire the locks and teardown the whole vgic), and simplifies the code significantly. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20231207151201.3028710-2-maz@kernel.org Signed-off-by: Oliver Upton Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kvm/vgic/vgic-init.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -382,26 +382,24 @@ void kvm_vgic_vcpu_destroy(struct kvm_vc vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF; } -static void __kvm_vgic_destroy(struct kvm *kvm) +void kvm_vgic_destroy(struct kvm *kvm) { struct kvm_vcpu *vcpu; unsigned long i; - lockdep_assert_held(&kvm->arch.config_lock); + mutex_lock(&kvm->slots_lock); vgic_debug_destroy(kvm); kvm_for_each_vcpu(i, vcpu, kvm) kvm_vgic_vcpu_destroy(vcpu); + mutex_lock(&kvm->arch.config_lock); + kvm_vgic_dist_destroy(kvm); -} -void kvm_vgic_destroy(struct kvm *kvm) -{ - mutex_lock(&kvm->arch.config_lock); - __kvm_vgic_destroy(kvm); mutex_unlock(&kvm->arch.config_lock); + mutex_unlock(&kvm->slots_lock); } /** @@ -469,25 +467,26 @@ int kvm_vgic_map_resources(struct kvm *k type = VGIC_V3; } - if (ret) { - __kvm_vgic_destroy(kvm); + if (ret) goto out; - } + dist->ready = true; dist_base = dist->vgic_dist_base; mutex_unlock(&kvm->arch.config_lock); ret = vgic_register_dist_iodev(kvm, dist_base, type); - if (ret) { + if (ret) kvm_err("Unable to register VGIC dist MMIO regions\n"); - kvm_vgic_destroy(kvm); - } - mutex_unlock(&kvm->slots_lock); - return ret; + goto out_slots; out: mutex_unlock(&kvm->arch.config_lock); +out_slots: mutex_unlock(&kvm->slots_lock); + + if (ret) + kvm_vgic_destroy(kvm); + return ret; }