From: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
To: Jarkko Sakkinen <jarkko@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Sean Christopherson <seanjc@google.com>,
Shuah Khan <shuah@kernel.org>,
x86@kernel.org, linux-sgx@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
Jia Zhang <zhang.jia@linux.alibaba.com>
Cc: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Subject: [PATCH v4 3/5] x86/sgx: Optimize the free_cnt count in sgx_epc_section
Date: Mon, 1 Feb 2021 21:26:51 +0800 [thread overview]
Message-ID: <20210201132653.35690-4-tianjia.zhang@linux.alibaba.com> (raw)
In-Reply-To: <20210201132653.35690-1-tianjia.zhang@linux.alibaba.com>
'section->free_cnt' represents the free page in sgx_epc_section,
which is assigned once after initialization. In fact, just after the
initialization is completed, the pages are in the init_laundry_list
list and cannot be allocated. This needs to be recovered by EREMOVE
of function sgx_sanitize_section() before it can be used as a page
that can be allocated. The sgx_sanitize_section() will be called in
the kernel thread ksgxd.
This patch moves the initialization of 'section->free_cnt' from the
initialization function sgx_setup_epc_section() to the function
sgx_sanitize_section(), and then accumulates the count after the
successful execution of EREMOVE. This seems to be more reasonable,
free_cnt will also truly reflect the allocatable free pages in EPC.
Sined-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kernel/cpu/sgx/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 4465912174fd..e455ec7b3449 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -48,6 +48,7 @@ static void sgx_sanitize_section(struct sgx_epc_section *section)
if (!ret) {
spin_lock(§ion->lock);
list_move(&page->list, §ion->page_list);
+ section->free_cnt++;
spin_unlock(§ion->lock);
} else
list_move_tail(&page->list, &dirty);
@@ -643,7 +644,6 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,
list_add_tail(§ion->pages[i].list, §ion->init_laundry_list);
}
- section->free_cnt = nr_pages;
return true;
}
--
2.19.1.3.ge56e4f7
next prev parent reply other threads:[~2021-02-01 13:29 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 13:26 [PATCH v4 0/5] Some optimizations related to sgx Tianjia Zhang
2021-02-01 13:26 ` [PATCH v4 1/5] selftests/x86: Use getauxval() to simplify the code in sgx Tianjia Zhang
2021-02-02 22:02 ` Jarkko Sakkinen
2021-02-09 0:09 ` Shuah Khan
2021-02-12 12:20 ` Jarkko Sakkinen
2021-02-01 13:26 ` [PATCH v4 2/5] x86/sgx: Reduce the locking range in sgx_sanitize_section() Tianjia Zhang
2021-02-02 22:00 ` Jarkko Sakkinen
2021-02-11 6:15 ` Tianjia Zhang
2021-02-01 13:26 ` Tianjia Zhang [this message]
2021-02-02 21:54 ` [PATCH v4 3/5] x86/sgx: Optimize the free_cnt count in sgx_epc_section Jarkko Sakkinen
2021-02-11 6:05 ` Tianjia Zhang
2021-02-01 13:26 ` [PATCH v4 4/5] x86/sgx: Allows ioctl PROVISION to execute before CREATE Tianjia Zhang
2021-02-02 21:57 ` Jarkko Sakkinen
2021-02-11 6:11 ` Tianjia Zhang
2021-02-01 13:26 ` [PATCH v4 5/5] x86/sgx: Remove redundant if conditions in sgx_encl_create Tianjia Zhang
2021-02-02 22:04 ` Jarkko Sakkinen
2021-02-11 6:17 ` Tianjia Zhang
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