From: Jarkko Sakkinen <jarkko@kernel.org>
To: ira.weiny@intel.com
Cc: Dave Hansen <dave.hansen@intel.com>,
Sean Christopherson <seanjc@google.com>,
Jethro Beekman <jethro@fortanix.com>,
linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org
Subject: Re: [PATCH v4] x86: Remove unnecessary kmap() from sgx_ioc_enclave_init()
Date: Sun, 7 Feb 2021 23:17:07 +0200 [thread overview]
Message-ID: <YCBY02iEKLVyj7Ix@kernel.org> (raw)
In-Reply-To: <20210205170030.856723-1-ira.weiny@intel.com>
On Fri, Feb 05, 2021 at 09:00:30AM -0800, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> kmap is inefficient and we are trying to reduce the usage in the kernel.
> There is no readily apparent reason why initp_page needs to be allocated
> and kmap'ed() but sigstruct needs to be page aligned and token
> 512 byte aligned.
>
> kmalloc() can give us this alignment but we need to allocate PAGE_SIZE
> bytes to do so. Rather than change this kmap() to kmap_local_page() use
> kmalloc() instead.
>
> Remove the alloc_page()/kmap() and replace with kmalloc(PAGE_SIZE, ...)
> to get a page aligned kernel address to use.
>
> In addition add a comment to document the alignment requirements so that
> others like myself don't attempt to 'fix' this again.
>
> Cc: Dave Hansen <dave.hansen@intel.com>
> Cc: Sean Christopherson <seanjc@google.com>
> Cc: Jethro Beekman <jethro@fortanix.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
/Jarkko
prev parent reply other threads:[~2021-02-07 21:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-05 17:00 [PATCH v4] x86: Remove unnecessary kmap() from sgx_ioc_enclave_init() ira.weiny
2021-02-05 17:03 ` Dave Hansen
2021-02-07 21:17 ` Jarkko Sakkinen [this message]
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