From nobody Wed Apr 24 22:42:32 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=citrix.com ARC-Seal: i=1; a=rsa-sha256; t=1595528833; cv=none; d=zohomail.com; s=zohoarc; b=KIv4k8SAD7O6eYbuftwbsap6U2lnCtlcEJEoW+P6PW34jMzE3oNJeAr9/Om3pqpZNGv5ln0VMRnjn0RdNvWvOVuoRjd7BgmPN9qR5R+C3v4fxQ7OQgHbxnJIVkFEgZdxra7S1TB4ktsMqq/a7W64AVAB2qc4OVlMh18YI7f7feo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1595528833; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To; bh=iusvW5phrxo89vADebtZ2OqFmvcTRF4zJyCmAQlINno=; b=i69bAjekUijvnxdnL0nIOQF7YjVvSVOXKOhXiCHUx5SybsTj3THLLSxlwCe9AVC0F069CaURM6gyNGnrt+KWQ7DdjspVIvvx+jSpVEPzM0og+kEaWhJvd3vOeEheeNb7I3+NUK8zmcReNnUeg4jV1SJXjNiEbAhgJQQ8PFavNI4= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 159552883348253.15724581167797; Thu, 23 Jul 2020 11:27:13 -0700 (PDT) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jyfvk-0005W7-Ta; Thu, 23 Jul 2020 18:26:56 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jyfvk-0005W1-60 for xen-devel@lists.xenproject.org; Thu, 23 Jul 2020 18:26:56 +0000 Received: from esa2.hc3370-68.iphmx.com (unknown [216.71.145.153]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 153a8c80-cd12-11ea-876c-bc764e2007e4; Thu, 23 Jul 2020 18:26:54 +0000 (UTC) X-Inumbo-ID: 153a8c80-cd12-11ea-876c-bc764e2007e4 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1595528814; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=U2+CiKFwpvLxh4d4IMieke3JfjjRWJo1j+sz6ZqIRBQ=; b=OHJFG2IdBBse5EnsfH2vLIoCxgPazZWr9VM9brC+EcLgFRmp5OSA1j2a 4rIpERm5FbV5xNETHV2zMvN31HCsze6sXI0diYGBpY8ajznCNrACwFD9K Im0wgNCXwha1IsjlI+i3GfrTsRXTOjnt1fglb0FWFeohUCiXTLgU0iQcx E=; Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: huDvZPas59Cux8i69MV9rDin8lFZkNRXN/fcYdCLfJNG6dTzbtnmBbZXSyObCLxPGbU6sz0uqR DrnU3jqSjlqgTzHUwuuDVm4Ime9uq6gqGSRXCSShg1CySsJe3aDnCNLzzJBKf89svGttKGIWEG Rkxwq+zlgFSeWJ57k5ksdgCjz+W6uazB+b9o5A7ryYNW+pBsD0fw7uJdKtO4nbNGsU8wPCFUqS CNdtugG1M36GOiWc+1QLMR1Wa2qzDLVvB6otzOI9GZCdA5CgzFWD7GTkdTx6Gnpk9ndvrhy5vT zzg= X-SBRS: 2.7 X-MesageID: 23086844 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.75,387,1589256000"; d="scan'208";a="23086844" From: Andrew Cooper To: Xen-devel Subject: [PATCH] x86/pv: Make the PV default WRMSR path match the HVM default Date: Thu, 23 Jul 2020 19:26:26 +0100 Message-ID: <20200723182626.7500-1-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Andrew Cooper , Wei Liu , Jan Beulich , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) The current HVM default for writes to unknown MSRs is to inject #GP if the = MSR is unreadable, and discard writes otherwise. While this behaviour isn't gre= at, the PV default is even worse, because it swallows writes even to non-readab= le MSRs. i.e. A PV guest doesn't even get a #GP fault for a write to a totally bogus index. Update PV to make it consistent with HVM, which will simplify the task of making other improvements to the default MSR behaviour. Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- CC: Jan Beulich CC: Wei Liu CC: Roger Pau Monn=C3=A9 --- xen/arch/x86/pv/emul-priv-op.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/pv/emul-priv-op.c b/xen/arch/x86/pv/emul-priv-op.c index f14552cb4b..efeb2a727e 100644 --- a/xen/arch/x86/pv/emul-priv-op.c +++ b/xen/arch/x86/pv/emul-priv-op.c @@ -1113,7 +1113,10 @@ static int write_msr(unsigned int reg, uint64_t val, } /* fall through */ default: - if ( (rdmsr_safe(reg, temp) !=3D 0) || (val !=3D temp) ) + if ( rdmsr_safe(reg, temp) ) + break; + + if ( val !=3D temp ) invalid: gdprintk(XENLOG_WARNING, "Domain attempted WRMSR %08x from 0x%016"PRIx64" to 0= x%016"PRIx64"\n", --=20 2.11.0