From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-229.mta0.migadu.com (out-229.mta0.migadu.com [91.218.175.229]) (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 398E03E494 for ; Wed, 20 Sep 2023 19:50:48 +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=1695239447; 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=VdzX8war5D0xFRhL0glcCvptW4Ze/njVqaHiKfO34Wo=; b=czDffILkbp5aAYIjPP8H4NJ3TZONhxhKUorhxQu5XgLr4efutRWI+z6cT9WAMuwPFXOLXT y07lgi04xZUiHt0iEq38ty16UXnqJZcTBp2vyAmw7jCefTZG92t1dLQKfLLYrzFThQdcmm 3kEprwp+m51suryes+Ak45p9MoiMmHU= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: kvm@vger.kernel.org, Marc Zyngier , James Morse , Suzuki K Poulose , Zenghui Yu , Oliver Upton Subject: [PATCH 1/8] KVM: arm64: Add generic check for system-supported vCPU features Date: Wed, 20 Sep 2023 19:50:29 +0000 Message-ID: <20230920195036.1169791-2-oliver.upton@linux.dev> In-Reply-To: <20230920195036.1169791-1-oliver.upton@linux.dev> References: <20230920195036.1169791-1-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 To date KVM has relied on kvm_reset_vcpu() failing when the vCPU feature flags are unsupported by the system. This is a bit messy since kvm_reset_vcpu() is called at runtime outside of the KVM_ARM_VCPU_INIT ioctl when it is expected to succeed. Further complicating the matter is that kvm_reset_vcpu() must tolerate be idemptotent to the config_lock, as it isn't consistently called with the lock held. Prepare to move feature compatibility checks out of kvm_reset_vcpu() with a 'generic' check that compares the user-provided flags with a computed maximum feature set for the system. Signed-off-by: Oliver Upton --- arch/arm64/kvm/arm.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 4866b3f7b4ea..66f3720cdd3a 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1190,6 +1190,16 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level, return -EINVAL; } +static unsigned long system_supported_vcpu_features(void) +{ + unsigned long features = KVM_VCPU_VALID_FEATURES; + + if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) + clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features); + + return features; +} + static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu, const struct kvm_vcpu_init *init) { @@ -1204,12 +1214,12 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu, return -ENOENT; } + if (features & ~system_supported_vcpu_features()) + return -EINVAL; + if (!test_bit(KVM_ARM_VCPU_EL1_32BIT, &features)) return 0; - if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) - return -EINVAL; - /* MTE is incompatible with AArch32 */ if (kvm_has_mte(vcpu->kvm)) return -EINVAL; -- 2.42.0.515.g380fc7ccd1-goog