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Subject: Re: [RFC PATCH 04/16] RISC-V: KVM: Implement VCPU create, init and
 destroy functions
To:     Anup Patel <anup@brainfault.org>
Cc:     Anup Patel <Anup.Patel@wdc.com>,
        Palmer Dabbelt <palmer@sifive.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Radim K <rkrcmar@redhat.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Atish Patra <Atish.Patra@wdc.com>,
        Alistair Francis <Alistair.Francis@wdc.com>,
        Damien Le Moal <Damien.LeMoal@wdc.com>,
        Christoph Hellwig <hch@infradead.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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 <20190729115544.17895-5-anup.patel@wdc.com>
 <ade614ae-fcfe-35f2-0519-1df71d035bcd@redhat.com>
 <2de10efc-56f8-ff47-ed69-7e471a099c80@redhat.com>
 <CAAhSdy0OH9h-R=2NxhhPs6jmFPNgZVSwFtCjtJrf++htu82ifA@mail.gmail.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
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Date:   Tue, 30 Jul 2019 13:47:49 +0200
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On 30/07/19 13:45, Anup Patel wrote:
>> so:
>>
>> 1) indeed we need SP2V=SPV=1 when entering guest mode
>>
>> 2) sstatus.SPP contains the guest mode
>>
>> 3) SP2P doesn't really matter for KVM since it never goes to VS-mode
>> from an interrupt handler, so if my reasoning is correct I'd leave it
>> clear, but I guess it's up to you whether to set it or not.
> Yes, SP2P does not matter but we set it to 1 here so that from Guest
> perspective it seems we were in S-mode previously.

But the guest never reads sstatus.SPP, it always reads, vsstatus.SPP
doesn't it?  In any case it doesn't matter.

Paolo