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Subject: Re: [PATCH v4 2/2] KVM: nSVM: implement ondemand allocation of the
 nested state
To:     Sean Christopherson <sean.j.christopherson@intel.com>,
        Maxim Levitsky <mlevitsk@redhat.com>
Cc:     kvm@vger.kernel.org, Vitaly Kuznetsov <vkuznets@redhat.com>,
        Ingo Molnar <mingo@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
References: <20200917101048.739691-1-mlevitsk@redhat.com>
 <20200917101048.739691-3-mlevitsk@redhat.com>
 <20200917162942.GE13522@sjchrist-ice>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <d9c0d190-c6ea-2e21-92ca-2a53efb86a1d@redhat.com>
Date:   Sat, 19 Sep 2020 17:09:09 +0200
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On 17/09/20 18:29, Sean Christopherson wrote:
>> +				vcpu->arch.efer = old_efer;
>> +				kvm_make_request(KVM_REQ_OUT_OF_MEMORY, vcpu);
> I really dislike KVM_REQ_OUT_OF_MEMORY.  It's redundant with -ENOMEM and
> creates a huge discrepancy with respect to existing code, e.g. nVMX returns
> -ENOMEM in a similar situation.

Maxim, your previous version was adding some error handling to
kvm_x86_ops.set_efer.  I don't remember what was the issue; did you have
any problems propagating all the errors up to KVM_SET_SREGS (easy),
kvm_set_msr (harder) etc.?

Paolo