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Date:   Wed, 2 Feb 2022 05:21:30 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Jane Chu <jane.chu@oracle.com>
Cc:     david@fromorbit.com, djwong@kernel.org, dan.j.williams@intel.com,
        hch@infradead.org, vishal.l.verma@intel.com, dave.jiang@intel.com,
        agk@redhat.com, snitzer@redhat.com, dm-devel@redhat.com,
        ira.weiny@intel.com, willy@infradead.org, vgoyal@redhat.com,
        linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev,
        linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org
Subject: Re: [PATCH v5 1/7] mce: fix set_mce_nospec to always unmap the whole
 page
Message-ID: <YfqFWjFcdJSwjRaU@infradead.org>
References: <20220128213150.1333552-1-jane.chu@oracle.com>
 <20220128213150.1333552-2-jane.chu@oracle.com>
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> +static inline int set_mce_nospec(unsigned long pfn)
>  {
>  	unsigned long decoy_addr;
>  	int rc;
> @@ -117,10 +113,7 @@ static inline int set_mce_nospec(unsigned long pfn, bool unmap)
>  	 */
>  	decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
>  
> -	if (unmap)
> -		rc = set_memory_np(decoy_addr, 1);
> -	else
> -		rc = set_memory_uc(decoy_addr, 1);
> +	rc = set_memory_np(decoy_addr, 1);
>  	if (rc)
>  		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
>  	return rc;
> @@ -130,7 +123,7 @@ static inline int set_mce_nospec(unsigned long pfn, bool unmap)
>  /* Restore full speculative operation to the pfn. */
>  static inline int clear_mce_nospec(unsigned long pfn)
>  {
> -	return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
> +	return _set_memory_present((unsigned long) pfn_to_kaddr(pfn), 1);
>  }

Wouldn't it make more sense to move these helpers out of line rather
than exporting _set_memory_present?

>  /*
> - * _set_memory_prot is an internal helper for callers that have been passed
> + * __set_memory_prot is an internal helper for callers that have been passed

This looks unrelated to the patch.