From owner-svn-src-all@freebsd.org Wed Dec 11 23:41:39 2019 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id B720D1E3675; Wed, 11 Dec 2019 23:41:39 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 47YD3R4RX8z3JFl; Wed, 11 Dec 2019 23:41:39 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 93BD41AFE2; Wed, 11 Dec 2019 23:41:39 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id xBBNfdns096678; Wed, 11 Dec 2019 23:41:39 GMT (envelope-from jhb@FreeBSD.org) Received: (from jhb@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id xBBNfdsE096677; Wed, 11 Dec 2019 23:41:39 GMT (envelope-from jhb@FreeBSD.org) Message-Id: <201912112341.xBBNfdsE096677@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jhb set sender to jhb@FreeBSD.org using -f From: John Baldwin Date: Wed, 11 Dec 2019 23:41:39 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r355634 - head/usr.sbin/bhyve X-SVN-Group: head X-SVN-Commit-Author: jhb X-SVN-Commit-Paths: head/usr.sbin/bhyve X-SVN-Commit-Revision: 355634 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Dec 2019 23:41:39 -0000 Author: jhb Date: Wed Dec 11 23:41:39 2019 New Revision: 355634 URL: https://svnweb.freebsd.org/changeset/base/355634 Log: Emulate reads of the PCI command register for passthrough devices. VFs return zero for the memory enable bit even if it has been set by a prior write. After r348779 this caused the annoying behavior that a guest OS would unintentionally disable memory decoding on a future read-modify-write operation on the command register. Instead, return the shadow value of the command register for reads. This ensures that the guest will only toggle the state of the memory enable bit when it specifically intends to do so. MFC after: 2 weeks Sponsored by: Chelsio Communications Modified: head/usr.sbin/bhyve/pci_passthru.c Modified: head/usr.sbin/bhyve/pci_passthru.c ============================================================================== --- head/usr.sbin/bhyve/pci_passthru.c Wed Dec 11 23:11:21 2019 (r355633) +++ head/usr.sbin/bhyve/pci_passthru.c Wed Dec 11 23:41:39 2019 (r355634) @@ -803,6 +803,19 @@ passthru_cfgread(struct vmctx *ctx, int vcpu, struct p } #endif + /* + * Emulate the command register. If a single read reads both the + * command and status registers, read the status register from the + * device's config space. + */ + if (coff == PCIR_COMMAND) { + if (bytes <= 2) + return (-1); + *rv = pci_get_cfgdata16(pi, PCIR_COMMAND) << 16 | + read_config(&sc->psc_sel, PCIR_STATUS, 2); + return (0); + } + /* Everything else just read from the device's config space */ *rv = read_config(&sc->psc_sel, coff, bytes);