From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 72E732E40B for ; Thu, 4 Jan 2024 19:33:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ptYFktOZ" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-5e20c9c4080so14923497b3.3 for ; Thu, 04 Jan 2024 11:33:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1704396802; x=1705001602; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=CN9HeZvjoKV2Wbxa5HUcERhzb0PDW7VNeTNnQhNqYY4=; b=ptYFktOZ81SR9eU2hJ+qphSNARh22huNILugdiXABtaA0IADQU+cv81LCFtAjRS8mx NTIYJFZsbntDvn+46Ee6iRusV8W1RabwWXU8Qtzzg26Xm3rXhrzmY2euURhjsS6kXIhV U8FaoCCh7FK4wolJvtK+3mkwSAPrfl3YUMGiuZxT/yq+3rkyeorWGzGL3y+Qpac+uSE8 3JA551Y7KREzM3B1irlYMDainzDCHo/DSqUSz6W5FnBGSCmF77HI5j/ORnQuMZSH7gaU BaBeZa8JBU5BehP9MFi+zjGBlWsGUSBWe3IXutxpAItgzpW/m5VPjIWZcP90RfGAZwqA W5kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704396802; x=1705001602; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=CN9HeZvjoKV2Wbxa5HUcERhzb0PDW7VNeTNnQhNqYY4=; b=S5P/T3BGush7QLdoDwt5D8M2kRpQwQTY69tfi3GfXQB5clkmqCW4nCZvVt5CAeVpzJ ps/H4cfMSAJ6hkEUj6pCSj2CIYEYVB25xQjPKJw/8OrKoSvHhxH3kKZpf0bL3OwRiruy LQdhiI0HFwZ7PpHiLWsEBlZWxU5/tt31DH/mCy94UjBXC5NoZiLdHBDFv0euvigs1Ivt bJmubbB4P5gavFGZE8Tq17vDvGXgGoyBp+tnEOryorSUbzzXslXgQM5J+NuYkOlaFnXi VWde6VtxSVdrodmlsDQW0pLVayHEDQNqJVsIY1cDV7R3QUMwv3ht4DMw187h2J4Al6VD pBDQ== X-Gm-Message-State: AOJu0YxMJnSk7THiz471gs3cX+FSSjZVoMt5984UBHFMu5kIt11RIR3P kJxcJUenL2Z2bouvKYTDN84fwhRlx22qSIS4sA== X-Google-Smtp-Source: AGHT+IFT/g6O0Qb3XCPrLkmEfM9ghUwoCpSLZ0U8QfzItbGRmdDrzn0VvnHqW7rZg6pFB83y2uw+DVets8Y= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:8512:0:b0:dbd:99af:daba with SMTP id w18-20020a258512000000b00dbd99afdabamr354711ybk.5.1704396802607; Thu, 04 Jan 2024 11:33:22 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 4 Jan 2024 11:33:03 -0800 In-Reply-To: <20240104193303.3175844-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240104193303.3175844-1-seanjc@google.com> X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog Message-ID: <20240104193303.3175844-9-seanjc@google.com> Subject: [GIT PULL] KVM: x86: Xen change for 6.8 From: Sean Christopherson To: Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Sean Christopherson Content-Type: text/plain; charset="UTF-8" A single Xen fix (of sorts) to let userspace workaround buggy guests that don't react well to KVM setting the "stable TSC" bit in Xen PV clocks. The following changes since commit e9e60c82fe391d04db55a91c733df4a017c28b2f: selftests/kvm: fix compilation on non-x86_64 platforms (2023-11-21 11:58:25 -0500) are available in the Git repository at: https://github.com/kvm-x86/linux.git tags/kvm-x86-xen-6.8 for you to fetch changes up to 6d72283526090850274d065cd5d60af732cc5fc8: KVM x86/xen: add an override for PVCLOCK_TSC_STABLE_BIT (2023-12-07 15:52:57 -0800) ---------------------------------------------------------------- KVM Xen change for 6.8: To workaround Xen guests that don't expect Xen PV clocks to be marked as being based on a stable TSC, add a Xen config knob to allow userspace to opt out of KVM setting the "TSC stable" bit in Xen PV clocks. Note, the "TSC stable" bit was added to the PVCLOCK ABI by KVM without an ack from Xen, i.e. KVM isn't entirely blameless for the buggy guest behavior. ---------------------------------------------------------------- Paul Durrant (1): KVM x86/xen: add an override for PVCLOCK_TSC_STABLE_BIT Documentation/virt/kvm/api.rst | 6 ++++++ arch/x86/kvm/x86.c | 28 +++++++++++++++++++++++----- arch/x86/kvm/xen.c | 9 ++++++++- include/uapi/linux/kvm.h | 1 + 4 files changed, 38 insertions(+), 6 deletions(-)