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Date:   Tue, 18 Oct 2022 16:45:26 +0000
From:   Quentin Perret <qperret@google.com>
To:     Will Deacon <will@kernel.org>
Cc:     kvmarm@lists.linux.dev, Sean Christopherson <seanjc@google.com>,
        Vincent Donnefort <vdonnefort@google.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        James Morse <james.morse@arm.com>,
        Chao Peng <chao.p.peng@linux.intel.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Fuad Tabba <tabba@google.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Marc Zyngier <maz@kernel.org>, kernel-team@android.com,
        kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 12/25] KVM: arm64: Add infrastructure to create and
 track pKVM instances at EL2
Message-ID: <Y07YJvEsUnjSasA0@google.com>
References: <20221017115209.2099-1-will@kernel.org>
 <20221017115209.2099-13-will@kernel.org>
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On Monday 17 Oct 2022 at 12:51:56 (+0100), Will Deacon wrote:
> +static int find_free_vm_table_entry(struct kvm *host_kvm)
> +{
> +	int i, ret = -ENOMEM;
> +
> +	for (i = 0; i < KVM_MAX_PVMS; ++i) {
> +		struct pkvm_hyp_vm *vm = vm_table[i];
> +
> +		if (!vm) {
> +			if (ret < 0)
> +				ret = i;
> +			continue;
> +		}
> +
> +		if (unlikely(vm->host_kvm == host_kvm)) {
> +			ret = -EEXIST;
> +			break;
> +		}

That would be funny if the host passed the same struct twice, but do we
care? If the host wants to shoot itself in the foot, it's not our
problem I guess :) ? Also, we don't do the same check for vCPUs so ...