From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9BB2819BC0 for ; Thu, 5 Oct 2023 13:16:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="YzW8BtG1" Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1696511808; x=1728047808; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6jCOPtPHdWrnAAWeulGySr3RPESjo4P/hViU3qiYp2Q=; b=YzW8BtG1Y724is3UFWiiVG1VgZcf+8DKOhodxrQvfHwbwe4zf0AibpPN tFmFGa6JLJp7xMDOToz/mBleUsRakAE5uqVvnnDkbcSQVWdazCv/LeL74 0N8MSPkx2r9M6Pw923U2PpruTu1ZTXhuL6Zg2z1DPD5kfLKwZMkTuWIMy bhfYW3XQZ+8a60J79iL16v1fjDa1QAsfiIfIwXZbuwx+zU0FmNTQKS2H6 TQjbUbcYXUqYOmXrWSXmmmciwcUV4+98tVMFtWEm2Mrh+uPlPcu+gZW8B wWkwZ+DoiDAutvrKX1z9nrbEaEIcIUjE7vyEv/vCx8EACGMS9QB7M7ZYv Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10854"; a="382357443" X-IronPort-AV: E=Sophos;i="6.03,203,1694761200"; d="scan'208";a="382357443" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2023 06:14:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10854"; a="817564301" X-IronPort-AV: E=Sophos;i="6.03,203,1694761200"; d="scan'208";a="817564301" Received: from skwasnia-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.251.222.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2023 06:14:16 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 35E2A10A14C; Thu, 5 Oct 2023 16:14:14 +0300 (+03) From: "Kirill A. Shutemov" To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH 04/13] x86/kvm: Do not try to disable kvmclock if it was not enabled Date: Thu, 5 Oct 2023 16:13:53 +0300 Message-ID: <20231005131402.14611-5-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231005131402.14611-1-kirill.shutemov@linux.intel.com> References: <20231005131402.14611-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit kvm_guest_cpu_offline() tries to disable kvmclock regardless if it is present in the VM. It leads to write to a MSR that doesn't exist on some configurations, namely in TDX guest: unchecked MSR access error: WRMSR to 0x12 (tried to write 0x0000000000000000) at rIP: 0xffffffff8110687c (kvmclock_disable+0x1c/0x30) kvmclock enabling is gated by CLOCKSOURCE and CLOCKSOURCE2 KVM paravirt features. Do not disable kvmclock if it was not enumerated or disabled by user from kernel command line. Signed-off-by: Kirill A. Shutemov Fixes: c02027b5742b ("x86/kvm: Disable kvmclock on all CPUs on shutdown") --- arch/x86/kernel/kvmclock.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index fb8f52149be9..cba2e732e53f 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -22,7 +22,7 @@ #include #include -static int kvmclock __initdata = 1; +static int kvmclock __ro_after_init = 1; static int kvmclock_vsyscall __initdata = 1; static int msr_kvm_system_time __ro_after_init = MSR_KVM_SYSTEM_TIME; static int msr_kvm_wall_clock __ro_after_init = MSR_KVM_WALL_CLOCK; @@ -195,7 +195,12 @@ static void kvm_setup_secondary_clock(void) void kvmclock_disable(void) { - native_write_msr(msr_kvm_system_time, 0, 0); + if (!kvm_para_available() || !kvmclock) + return; + + if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE) || + kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE2)) + native_write_msr(msr_kvm_system_time, 0, 0); } static void __init kvmclock_init_mem(void) -- 2.41.0