Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
In-Reply-To: <20180126211643.GB6520@codeblueprint.co.uk>
References: <1516309264-23926-1-git-send-email-sai.praneeth.prakhya@intel.com> <20180126211643.GB6520@codeblueprint.co.uk>
From:   Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date:   Mon, 29 Jan 2018 10:51:26 +0000
Message-ID: <CAKv+Gu-mrMpgFVssUH1RXP6GAKuPNtQwwsCNTqv2Oa48FrU+Bg@mail.gmail.com>
Subject: Re: [PATCH V4 0/3] Use mm_struct and switch_mm() instead of manually
To:     Matt Fleming <matt@codeblueprint.co.uk>
Cc:     Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
        linux-efi@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "Lee, Chun-Yi" <jlee@suse.com>, Borislav Petkov <bp@alien8.de>,
        Tony Luck <tony.luck@intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Ricardo Neri <ricardo.neri@intel.com>,
        Ravi Shankar <ravi.v.shankar@intel.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 26 January 2018 at 21:16, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Thu, 18 Jan, at 01:01:04PM, Sai Praneeth Prakhya wrote:
>> From: Sai Praneeth <sai.praneeth.prakhya@intel.com>
>>
>> Presently, in x86, to invoke any efi function like
>> efi_set_virtual_address_map() or any efi_runtime_service() the code path
>> typically involves read_cr3() (save previous pgd), write_cr3()
>> (write efi_pgd) and calling efi function. Likewise after returning from
>> efi function the code path typically involves read_cr3() (save efi_pgd),
>> write_cr3() (write previous pgd). We do this couple of times in efi
>> subsystem of Linux kernel, instead we can use helper function
>> efi_switch_mm() to do this. This improves readability and maintainability.
>> Also, instead of maintaining a separate struct "efi_scratch" to store/restore
>> efi_pgd, we can use mm_struct to do this.
>
> FWIW this series looks OK to me.
>
> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>

Thanks Matt

I know the x86 guys have been rather busy lately, so I will give them
some more time to respond. If there are no objections raised, I will
queue it for v4.17 in a couple of weeks.