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From:   Atish Patra <atishp@atishpatra.org>
Date:   Tue, 12 Jul 2022 18:23:23 -0700
Message-ID: <CAOnJCUKjFMMsrNWR=hzB+qbw4SECWS3+DOJDun90emnM-Vkpiw@mail.gmail.com>
Subject: Re: [PATCH 4/5] RISC-V: KVM: Use PAGE_KERNEL_IO in kvm_riscv_gstage_ioremap()
To:     Anup Patel <apatel@ventanamicro.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Alistair Francis <Alistair.Francis@wdc.com>,
        Anup Patel <anup@brainfault.org>,
        KVM General <kvm@vger.kernel.org>,
        "open list:KERNEL VIRTUAL MACHINE FOR RISC-V (KVM/riscv)" 
        <kvm-riscv@lists.infradead.org>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        "linux-kernel@vger.kernel.org List" <linux-kernel@vger.kernel.org>
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On Thu, Jul 7, 2022 at 7:53 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> When the host has Svpbmt extension, we should use page based memory
> type 2 (i.e. IO) for IO mappings in the G-stage page table.
>
> To achieve this, we replace use of PAGE_KERNEL with PAGE_KERNEL_IO
> in the kvm_riscv_gstage_ioremap().
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/kvm/mmu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
> index f7862ca4c4c6..bc545aef6034 100644
> --- a/arch/riscv/kvm/mmu.c
> +++ b/arch/riscv/kvm/mmu.c
> @@ -361,7 +361,7 @@ int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa,
>         pfn = __phys_to_pfn(hpa);
>
>         for (addr = gpa; addr < end; addr += PAGE_SIZE) {
> -               pte = pfn_pte(pfn, PAGE_KERNEL);
> +               pte = pfn_pte(pfn, PAGE_KERNEL_IO);
>
>                 if (!writable)
>                         pte = pte_wrprotect(pte);
> --
> 2.34.1
>

LGTM.

Reviewed-by: Atish Patra <atishp@rivosinc.com>

-- 
Regards,
Atish