Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 8 Nov 2022 07:35:36 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     xiafukun <xiafukun@huawei.com>, Ard Biesheuvel <ardb@kernel.org>
Cc:     arnd@arndb.de, keescook@chromium.org, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, yusongping@huawei.com,
        zhaowenhui8@huawei.comx
Subject: Re: vmlinux.lds.h: Bug report: unable to handle page fault when
 start the virtual machine with qemu
Message-ID: <Y2ppOJ4zguDznRAc@dev-arch.thelio-3990X>
References: <cbbd3548-880c-d2ca-1b67-5bb93b291d5f@huawei.com>
 <CAMj1kXESRP9RvhPC5Wgg38BqyCn5ANv7+X9Ezyx5MXNNvEZ1kA@mail.gmail.com>
 <b714ad78-4689-ad0b-9316-efcc1665f6bf@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <b714ad78-4689-ad0b-9316-efcc1665f6bf@huawei.com>
Precedence: bulk

On Tue, Nov 08, 2022 at 03:46:32PM +0800, xiafukun wrote:
> Thank you for your reply.
> We tested your changes to this patch and did fix the issue. Following the
> solution you provided, we recompile the kernel and successfully start the
> virtual machine.

Thank you a lot for testing and sorry about the breakage in the first
place :(

Ard, were you going to send a patch? Feel free to preemptively add:

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

if so; otherwise, I can send one later today.

> 在 2022/11/8 0:00, Ard Biesheuvel 写道:
> > 
> > That patch looks incorrect to me. Without CONFIG_SMP, the PERCPU
> > sections are not instantiated, and the only copy of those variables is
> > created in the ordinary .data/.bss sections
> > 
> > Does the change below fix the issue for you?
> > 
> > --- a/include/asm-generic/vmlinux.lds.h
> > +++ b/include/asm-generic/vmlinux.lds.h
> > @@ -347,6 +347,7 @@
> >  #define DATA_DATA                                                      \
> >         *(.xiptext)                                                     \
> >         *(DATA_MAIN)                                                    \
> > +       *(.data..decrypted)                                             \
> >         *(.ref.data)                                                    \
> >         *(.data..shared_aligned) /* percpu related */                   \
> >         MEM_KEEP(init.data*)                                            \
> > @@ -995,7 +996,6 @@
> >  #ifdef CONFIG_AMD_MEM_ENCRYPT
> >  #define PERCPU_DECRYPTED_SECTION                                       \
> >         . = ALIGN(PAGE_SIZE);                                           \
> > -       *(.data..decrypted)                                             \
> >         *(.data..percpu..decrypted)                                     \
> >         . = ALIGN(PAGE_SIZE);
> >  #else