From owner-svn-src-all@FreeBSD.ORG Sun Oct 26 03:03:42 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 752B34F3; Sun, 26 Oct 2014 03:03:42 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 48A39E2A; Sun, 26 Oct 2014 03:03:42 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id s9Q33gwa008647; Sun, 26 Oct 2014 03:03:42 GMT (envelope-from neel@FreeBSD.org) Received: (from neel@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id s9Q33gmX008646; Sun, 26 Oct 2014 03:03:42 GMT (envelope-from neel@FreeBSD.org) Message-Id: <201410260303.s9Q33gmX008646@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: neel set sender to neel@FreeBSD.org using -f From: Neel Natu Date: Sun, 26 Oct 2014 03:03:42 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r273666 - head/sys/amd64/vmm X-SVN-Group: head 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: 2.1.18-1 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: Sun, 26 Oct 2014 03:03:42 -0000 Author: neel Date: Sun Oct 26 03:03:41 2014 New Revision: 273666 URL: https://svnweb.freebsd.org/changeset/base/273666 Log: Don't pass the 'error' return from an I/O port handler directly to vm_run(). Most I/O port handlers return -1 to signal an error. If this value is returned without modification to vm_run() then it leads to incorrect behavior because '-1' is interpreted as ERESTART at the system call level. Fix this by always returning EIO to signal an error from an I/O port handler. MFC after: 1 week Modified: head/sys/amd64/vmm/vmm_ioport.c Modified: head/sys/amd64/vmm/vmm_ioport.c ============================================================================== --- head/sys/amd64/vmm/vmm_ioport.c Sun Oct 26 02:53:23 2014 (r273665) +++ head/sys/amd64/vmm/vmm_ioport.c Sun Oct 26 03:03:41 2014 (r273666) @@ -106,15 +106,14 @@ emulate_inout_port(struct vm *vm, int vc uint32_t mask, val; int error; - error = 0; - *retu = true; - - if (vmexit->u.inout.port >= MAX_IOPORTS) - goto done; - - handler = ioport_handler[vmexit->u.inout.port]; - if (handler == NULL) - goto done; + /* + * If there is no handler for the I/O port then punt to userspace. + */ + if (vmexit->u.inout.port >= MAX_IOPORTS || + (handler = ioport_handler[vmexit->u.inout.port]) == NULL) { + *retu = true; + return (0); + } mask = vie_size2mask(vmexit->u.inout.bytes); @@ -124,20 +123,27 @@ emulate_inout_port(struct vm *vm, int vc error = (*handler)(vm, vcpuid, vmexit->u.inout.in, vmexit->u.inout.port, vmexit->u.inout.bytes, &val); + if (error) { + /* + * The value returned by this function is also the return value + * of vm_run(). This needs to be a positive number otherwise it + * can be interpreted as a "pseudo-error" like ERESTART. + * + * Enforce this by mapping all errors to EIO. + */ + return (EIO); + } - if (!error) { - *retu = false; - if (vmexit->u.inout.in) { - vmexit->u.inout.eax &= ~mask; - vmexit->u.inout.eax |= val & mask; - error = vm_set_register(vm, vcpuid, - VM_REG_GUEST_RAX, vmexit->u.inout.eax); - KASSERT(error == 0, ("emulate_ioport: error %d " - "setting guest rax register", error)); - } + if (vmexit->u.inout.in) { + vmexit->u.inout.eax &= ~mask; + vmexit->u.inout.eax |= val & mask; + error = vm_set_register(vm, vcpuid, VM_REG_GUEST_RAX, + vmexit->u.inout.eax); + KASSERT(error == 0, ("emulate_ioport: error %d setting guest " + "rax register", error)); } -done: - return (error); + *retu = false; + return (0); } static int