linux-kernel - [PATCH v2 1/5] kvm: Add gfn_to_page_no_pin() to translate gfn to page without pinning.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1404824492-30095-2-git-send-email-tangchen@cn.fujitsu.com>
Date:	Tue, 8 Jul 2014 21:01:28 +0800
From:	Tang Chen <tangchen@...fujitsu.com>
To:	<gleb@...nel.org>, <mtosatti@...hat.com>, <nadav.amit@...il.com>
CC:	<kvm@...r.kernel.org>, <laijs@...fujitsu.com>,
	<isimatu.yasuaki@...fujitsu.com>, <guz.fnst@...fujitsu.com>,
	<linux-kernel@...r.kernel.org>, <tangchen@...fujitsu.com>
Subject: [PATCH v2 1/5] kvm: Add gfn_to_page_no_pin() to translate gfn to page without pinning.

gfn_to_page() will finally call hva_to_pfn() to get the pfn, and pin the page
in memory by calling GUP functions. This function unpins the page.

Will be used by the followed patches.

Signed-off-by: Tang Chen <tangchen@...fujitsu.com>
---
 include/linux/kvm_host.h |  1 +
 virt/kvm/kvm_main.c      | 17 ++++++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ec4e3bd..7c58d9d 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -541,6 +541,7 @@ int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
 			    int nr_pages);
 
 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
+struct page *gfn_to_page_no_pin(struct kvm *kvm, gfn_t gfn);
 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn);
 unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable);
 unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4b6c01b..6091849 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1371,9 +1371,24 @@ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
 
 	return kvm_pfn_to_page(pfn);
 }
-
 EXPORT_SYMBOL_GPL(gfn_to_page);
 
+struct page *gfn_to_page_no_pin(struct kvm *kvm, gfn_t gfn)
+{
+	struct page *page = gfn_to_page(kvm, gfn);
+
+	/*
+	 * gfn_to_page() will finally call hva_to_pfn() to get the pfn, and pin
+	 * the page in memory by calling GUP functions. This function unpins
+	 * the page.
+	 */
+	if (!is_error_page(page))
+		put_page(page);
+
+	return page;
+}
+EXPORT_SYMBOL_GPL(gfn_to_page_no_pin);
+
 void kvm_release_page_clean(struct page *page)
 {
 	WARN_ON(is_error_page(page));
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/