[RFC PATCH 3/6] x86/kvm: Add CONFIG_KVM_VIRT_SUSPEND_TIMING

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>, Jim Mattson <jmattson@google.com>,
	Joerg Roedel <joro@8bytes.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	linux-kernel@vger.kernel.org, x86@kernel.org
Subject: [RFC PATCH 3/6] x86/kvm: Add CONFIG_KVM_VIRT_SUSPEND_TIMING
Date: Mon, 26 Apr 2021 18:06:42 +0900	[thread overview]
Message-ID: <20210426090644.2218834-4-hikalium@chromium.org> (raw)
In-Reply-To: <20210426090644.2218834-1-hikalium@chromium.org>

The config option can be used to enable virtual suspend time injection
support on kvm hosts.

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

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

diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index a788d5120d4d..6cb6795726a2 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -119,4 +119,17 @@ config KVM_MMU_AUDIT
 	 This option adds a R/W kVM module parameter 'mmu_audit', which allows
 	 auditing of KVM MMU events at runtime.
 
+config KVM_VIRT_SUSPEND_TIMING
+	bool "Virtual suspend time injection"
+	depends on KVM=y
+	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.
+
 endif # VIRTUALIZATION
-- 
2.31.1.498.g6c1eba8ee3d-goog

