linux-kernel - Re: [PATCH] x86/xen: fix booting 32-bit pv guest

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Message-ID: <ee2aa0c4-b633-a5e6-436c-0776407c98ac@oracle.com>
Date:   Thu, 9 Apr 2020 10:44:25 -0400
From:   Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:     Juergen Gross <jgross@...e.com>, xen-devel@...ts.xenproject.org,
        x86@...nel.org, linux-kernel@...r.kernel.org
Cc:     Stefano Stabellini <sstabellini@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH] x86/xen: fix booting 32-bit pv guest


On 4/9/20 3:00 AM, Juergen Gross wrote:
> Commit 2f62f36e62daec ("x86/xen: Make the boot CPU idle task reliable")
> introduced a regression for booting 32 bit Xen PV guests: the address
> of the initial stack needs to be a virtual one.
>
> Fixes: 2f62f36e62daec ("x86/xen: Make the boot CPU idle task reliable")
> Signed-off-by: Juergen Gross <jgross@...e.com>


Reviewed-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>


> ---
>  arch/x86/xen/xen-head.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
> index 7d1c4fcbe8f7..1ba601df3a37 100644
> --- a/arch/x86/xen/xen-head.S
> +++ b/arch/x86/xen/xen-head.S
> @@ -38,7 +38,7 @@ SYM_CODE_START(startup_xen)
>  #ifdef CONFIG_X86_64


While at it, I'd swap the ifdefs and fold x86_64 case into the one below.


>  	mov initial_stack(%rip), %rsp
>  #else
> -	mov pa(initial_stack), %esp
> +	mov initial_stack, %esp
>  #endif
>  
>  #ifdef CONFIG_X86_64