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]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YCBY02iEKLVyj7Ix@kernel.org \
--to=jarkko@kernel.org \
--cc=dave.hansen@intel.com \
--cc=ira.weiny@intel.com \
--cc=jethro@fortanix.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sgx@vger.kernel.org \
--cc=seanjc@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).