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From:   Hikaru Nishida <hikalium@chromium.org>
To:     kvm@vger.kernel.org
Cc:     suleiman@google.com, Hikaru Nishida <hikalium@chromium.org>,
        Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org, x86@kernel.org
Subject: [RFC PATCH 5/6] x86/kvm: Add CONFIG_KVM_VIRT_SUSPEND_TIMING_GUEST
Date:   Mon, 26 Apr 2021 18:06:44 +0900
Message-Id: <20210426090644.2218834-6-hikalium@chromium.org>
In-Reply-To: <20210426090644.2218834-1-hikalium@chromium.org>
References: <20210426090644.2218834-1-hikalium@chromium.org>
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The config option can be used to enable virtual suspend time injection
support on kvm guests.

Signed-off-by: Hikaru Nishida <hikalium@chromium.org>
---

 arch/x86/Kconfig | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2792879d398e..fac06534c30a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -825,6 +825,19 @@ config KVM_GUEST
 	  underlying device model, the host provides the guest with
 	  timing infrastructure such as time of day, and system time
 
+config KVM_VIRT_SUSPEND_TIMING_GUEST
+	bool "Virtual suspend time injection (guest side)"
+	depends on KVM_GUEST
+	default n
+	help
+	 This option makes the host's suspension reflected on the guest's clocks.
+	 In other words, guest's CLOCK_MONOTONIC will stop and
+	 CLOCK_BOOTTIME keeps running during the host's suspension.
+	 This feature will only be effective when both guest and host enable
+	 this option.
+
+	 If unsure, say N.
+
 config ARCH_CPUIDLE_HALTPOLL
 	def_bool n
 	prompt "Disable host haltpoll when loading haltpoll driver"
-- 
2.31.1.498.g6c1eba8ee3d-goog