From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-90.mta1.migadu.com (out-90.mta1.migadu.com [95.215.58.90]) (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 7FC0F17FEA for ; Wed, 2 Aug 2023 23:43:29 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1691019807; 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=CaICPhhELecZHoZ/Gz1gMzhbwDzRan7ZPk8QTArXZok=; b=vDYC2nTroLDA+dnOvzJgtzV51SXiZenvG4E02+vVKNpxF5hPFvwTaINC9+rAPr8hyQX0Jk xcomIu7R/SdAF8KyXPY7hUveIVJZWuv9HKmvTHveUigkFvsS8mnufo2C5mEtcKx8QEwfVH sjEkXHTF6nRU5ou5kFOgJ5j3EWnXJ0U= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: kvm@vger.kernel.org, Marc Zyngier , James Morse , Suzuki K Poulose , Zenghui Yu , Will Deacon , Julien Thierry , Salil Mehta , Oliver Upton Subject: [PATCH kvmtool v3 08/17] Add helpers to pause the VM from vCPU thread Date: Wed, 2 Aug 2023 23:42:46 +0000 Message-ID: <20230802234255.466782-9-oliver.upton@linux.dev> In-Reply-To: <20230802234255.466782-1-oliver.upton@linux.dev> References: <20230802234255.466782-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Pausing the VM from a vCPU thread is perilous with the current helpers, as it waits indefinitely for a signal that never comes when invoked from a vCPU thread. Instead, add a helper for pausing the VM from a vCPU, working around the issue by explicitly marking the caller as paused before proceeding. Signed-off-by: Oliver Upton --- include/kvm/kvm-cpu.h | 3 +++ kvm-cpu.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/kvm/kvm-cpu.h b/include/kvm/kvm-cpu.h index 0f16f8d6e872..9a4901bf94ca 100644 --- a/include/kvm/kvm-cpu.h +++ b/include/kvm/kvm-cpu.h @@ -29,4 +29,7 @@ void kvm_cpu__show_page_tables(struct kvm_cpu *vcpu); void kvm_cpu__arch_nmi(struct kvm_cpu *cpu); void kvm_cpu__run_on_all_cpus(struct kvm *kvm, struct kvm_cpu_task *task); +void kvm_cpu__pause_vm(struct kvm_cpu *vcpu); +void kvm_cpu__continue_vm(struct kvm_cpu *vcpu); + #endif /* KVM__KVM_CPU_H */ diff --git a/kvm-cpu.c b/kvm-cpu.c index 1c566b3f21d6..9adc9d4f7841 100644 --- a/kvm-cpu.c +++ b/kvm-cpu.c @@ -141,6 +141,22 @@ void kvm_cpu__run_on_all_cpus(struct kvm *kvm, struct kvm_cpu_task *task) mutex_unlock(&task_lock); } +void kvm_cpu__pause_vm(struct kvm_cpu *vcpu) +{ + /* + * Mark the calling vCPU as paused to avoid waiting indefinitely for a + * signal exit. + */ + vcpu->paused = true; + kvm__pause(vcpu->kvm); +} + +void kvm_cpu__continue_vm(struct kvm_cpu *vcpu) +{ + vcpu->paused = false; + kvm__continue(vcpu->kvm); +} + int kvm_cpu__start(struct kvm_cpu *cpu) { sigset_t sigset; -- 2.41.0.585.gd2178a4bd4-goog