linux-kernel - [RFC PATCH QEMU] i386/kvm: Enable paravirtual unused page hint mechanism

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: <20190204181825.12252.81443.stgit@localhost.localdomain>
Date:   Mon, 04 Feb 2019 10:19:49 -0800
From:   Alexander Duyck <alexander.duyck@...il.com>
To:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Cc:     rkrcmar@...hat.com, alexander.h.duyck@...ux.intel.com,
        x86@...nel.org, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        pbonzini@...hat.com, tglx@...utronix.de, akpm@...ux-foundation.org
Subject: [RFC PATCH QEMU] i386/kvm: Enable paravirtual unused page hint
 mechanism

From: Alexander Duyck <alexander.h.duyck@...ux.intel.com>

This patch adds the flag named kvm-pv-unused-page-hint. This functionality
is enabled by kvm for x86 and provides a mechanism by which the guest can
indicate to the host which pages it is no longer using. By providing these
hints the guest can help to reduce the memory pressure on the host as
dirtied pages will be cleared and not written out to swap if they are
marked as being unused.

Signed-off-by: Alexander Duyck <alexander.h.duyck@...ux.intel.com>
---
 target/i386/cpu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 2f5412592d30..0d19a9dc64f1 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -900,7 +900,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             "kvmclock", "kvm-nopiodelay", "kvm-mmu", "kvmclock",
             "kvm-asyncpf", "kvm-steal-time", "kvm-pv-eoi", "kvm-pv-unhalt",
             NULL, "kvm-pv-tlb-flush", NULL, "kvm-pv-ipi",
-            NULL, NULL, NULL, NULL,
+            "kvm-pv-unused-page-hint", NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
             "kvmclock-stable-bit", NULL, NULL, NULL,