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Message-ID: <dba58cf1-59ed-f1f3-fdbe-59d213f0a7b5@linaro.org>
Date:   Tue, 11 Jul 2023 16:12:54 +0200
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Subject: Re: [PATCH v2 2/2] KVM: s390: pv: fix index value of replaced ASCE
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To:     Claudio Imbrenda <imbrenda@linux.ibm.com>, kvm@vger.kernel.org
Cc:     linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
        frankja@linux.ibm.com, mhartmay@linux.ibm.com, nsg@linux.ibm.com,
        borntraeger@de.ibm.com, nrb@linux.ibm.com
References: <20230705111937.33472-1-imbrenda@linux.ibm.com>
 <20230705111937.33472-3-imbrenda@linux.ibm.com>
From:   =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= <philmd@linaro.org>
In-Reply-To: <20230705111937.33472-3-imbrenda@linux.ibm.com>
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On 5/7/23 13:19, Claudio Imbrenda wrote:
> The index field of the struct page corresponding to a guest ASCE should
> be 0. When replacing the ASCE in s390_replace_asce(), the index of the
> new ASCE should also be set to 0.
> 
> Having the wrong index might lead to the wrong addresses being passed
> around when notifying pte invalidations, and eventually to validity
> intercepts (VM crash) if the prefix gets unmapped and the notifier gets
> called with the wrong address.

Can that also happen in crst_table_alloc()?

> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
>   arch/s390/mm/gmap.c | 1 +
>   1 file changed, 1 insertion(+)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>