From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-19.mta1.migadu.com (out-19.mta1.migadu.com [95.215.58.19]) (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 6FA6F408EE for ; Fri, 9 Jun 2023 19:01:11 +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=1686337269; 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=9BSuh5Q5IEL511Ru0FSGzPDSAuZ9VLVSvBqaJ5AKQq8=; b=gapKDPK0aWqkhA/pxeEc9E/VL/5R1C+pSYB/yyqtNtyhSTMpU/ttibcwjXVNd4pfUmEAkS 2xQQwOCaCJ4hVYvV+3DWvWAJpmMXV4qQOwzaTAKN/OQ7xCIFkTW4YpBVGaCKTaMr8IrEnf PqlX5q9NMS0n3J+NIHITDz5hAXNYEiI= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: Marc Zyngier , James Morse , Suzuki K Poulose , Zenghui Yu , Will Deacon , Catalin Marinas , Fuad Tabba , linux-arm-kernel@lists.infradead.org, surajjs@amazon.com, Cornelia Huck , Shameerali Kolothum Thodi , Jing Zhang , Oliver Upton Subject: [PATCH v12 02/11] KVM: arm64: Relax invariance of KVM_ARM_VCPU_POWER_OFF Date: Fri, 9 Jun 2023 19:00:45 +0000 Message-ID: <20230609190054.1542113-3-oliver.upton@linux.dev> In-Reply-To: <20230609190054.1542113-1-oliver.upton@linux.dev> References: <20230609190054.1542113-1-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 Allow the value of KVM_ARM_VCPU_POWER_OFF to differ between calls to KVM_ARM_VCPU_INIT. Userspace can already change the state of the vCPU through the KVM_SET_MP_STATE ioctl, so making the bit invariant seems needlessly restrictive. Signed-off-by: Oliver Upton --- arch/arm64/kvm/arm.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index d5298054a8ed..a9c18f45df3f 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1236,8 +1236,19 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu, static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init) { + bool power_off = false; int ret; + /* + * Treat the power-off vCPU feature as ephemeral. Clear the bit to avoid + * reflecting it in the finalized feature set, thus limiting its scope + * to a single KVM_ARM_VCPU_INIT call. + */ + if (init->features[0] & KVM_ARM_VCPU_POWER_OFF) { + init->features[0] &= ~KVM_ARM_VCPU_POWER_OFF; + power_off = true; + } + ret = kvm_vcpu_set_target(vcpu, init); if (ret) return ret; @@ -1266,7 +1277,7 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, */ spin_lock(&vcpu->arch.mp_state_lock); - if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) + if (power_off) __kvm_arm_vcpu_power_off(vcpu); else WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE); -- 2.41.0.162.gfafddb0af9-goog