Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755326Ab2JPA3u (ORCPT ); Mon, 15 Oct 2012 20:29:50 -0400 Received: from smtp-outbound-2.vmware.com ([208.91.2.13]:39477 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754721Ab2JPA3s (ORCPT ); Mon, 15 Oct 2012 20:29:48 -0400 Subject: [PATCH 09/10] VMCI: routing implementation. To: linux-kernel@vger.kernel.org, georgezhang@vmware.com, virtualization@lists.linux-foundation.org From: George Zhang Cc: pv-drivers@vmware.com, vm-crosstalk@vmware.com, gregkh@linuxfoundation.org Date: Mon, 15 Oct 2012 17:29:48 -0700 Message-ID: <20121016002942.26205.72888.stgit@promb-2n-dhcp175.eng.vmware.com> In-Reply-To: <20121016002550.26205.67037.stgit@promb-2n-dhcp175.eng.vmware.com> References: <20121016002550.26205.67037.stgit@promb-2n-dhcp175.eng.vmware.com> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8973 Lines: 297 VMCI routing code is responsible for routing between various hosts/guests as well as routing in nested scenarios. Signed-off-by: George Zhang --- drivers/misc/vmw_vmci/vmci_route.c | 237 ++++++++++++++++++++++++++++++++++++ drivers/misc/vmw_vmci/vmci_route.h | 30 +++++ 2 files changed, 267 insertions(+), 0 deletions(-) create mode 100644 drivers/misc/vmw_vmci/vmci_route.c create mode 100644 drivers/misc/vmw_vmci/vmci_route.h diff --git a/drivers/misc/vmw_vmci/vmci_route.c b/drivers/misc/vmw_vmci/vmci_route.c new file mode 100644 index 0000000..8aa43ee --- /dev/null +++ b/drivers/misc/vmw_vmci/vmci_route.c @@ -0,0 +1,237 @@ +/* + * VMware VMCI Driver + * + * Copyright (C) 2012 VMware, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 and no later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include +#include + +#include "vmci_common_int.h" +#include "vmci_context.h" +#include "vmci_driver.h" +#include "vmci_route.h" + +/* + * Make a routing decision for the given source and destination handles. + * This will try to determine the route using the handles and the available + * devices. Will set the source context if it is invalid. + */ +int vmci_route(struct vmci_handle *src, + const struct vmci_handle *dst, + bool from_guest, + enum vmci_route *route) +{ + bool has_host_device = vmci_host_code_active(); + bool has_guest_device = vmci_guest_code_active(); + + ASSERT(src); + ASSERT(dst); + ASSERT(route); + + *route = VMCI_ROUTE_NONE; + + /* + * "from_guest" is only ever set to true by + * IOCTL_VMCI_DATAGRAM_SEND (or by the vmkernel equivalent), + * which comes from the VMX, so we know it is coming from a + * guest. + * + * To avoid inconsistencies, test these once. We will test + * them again when we do the actual send to ensure that we do + * not touch a non-existent device. + */ + + /* Must have a valid destination context. */ + if (VMCI_INVALID_ID == dst->context) + return VMCI_ERROR_INVALID_ARGS; + + /* Anywhere to hypervisor. */ + if (VMCI_HYPERVISOR_CONTEXT_ID == dst->context) { + + /* + * If this message already came from a guest then we + * cannot send it to the hypervisor. It must come + * from a local client. + */ + if (from_guest) + return VMCI_ERROR_DST_UNREACHABLE; + + /* + * We must be acting as a guest in order to send to + * the hypervisor. + */ + if (!has_guest_device) + return VMCI_ERROR_DEVICE_NOT_FOUND; + + /* And we cannot send if the source is the host context. */ + if (VMCI_HOST_CONTEXT_ID == src->context) + return VMCI_ERROR_INVALID_ARGS; + + /* + * If the client passed the ANON source handle then + * respect it (both context and resource are invalid). + * However, if they passed only an invalid context, + * then they probably mean ANY, in which case we + * should set the real context here before passing it + * down. + */ + if (VMCI_INVALID_ID == src->context && + VMCI_INVALID_ID != src->resource) + src->context = vmci_get_context_id(); + + /* Send from local client down to the hypervisor. */ + *route = VMCI_ROUTE_AS_GUEST; + return VMCI_SUCCESS; + } + + /* Anywhere to local client on host. */ + if (VMCI_HOST_CONTEXT_ID == dst->context) { + /* + * If it is not from a guest but we are acting as a + * guest, then we need to send it down to the host. + * Note that if we are also acting as a host then this + * will prevent us from sending from local client to + * local client, but we accept that restriction as a + * way to remove any ambiguity from the host context. + */ + if (src->context == VMCI_HYPERVISOR_CONTEXT_ID) { + /* + * If the hypervisor is the source, this is + * host local communication. The hypervisor + * may send vmci event datagrams to the host + * itself, but it will never send datagrams to + * an "outer host" through the guest device. + */ + + if (has_host_device) { + *route = VMCI_ROUTE_AS_HOST; + return VMCI_SUCCESS; + } else { + return VMCI_ERROR_DEVICE_NOT_FOUND; + } + } + + if (!from_guest && has_guest_device) { + /* If no source context then use the current. */ + if (VMCI_INVALID_ID == src->context) + src->context = vmci_get_context_id(); + + /* Send it from local client down to the host. */ + *route = VMCI_ROUTE_AS_GUEST; + return VMCI_SUCCESS; + } + + /* + * Otherwise we already received it from a guest and + * it is destined for a local client on this host, or + * it is from another local client on this host. We + * must be acting as a host to service it. + */ + if (!has_host_device) + return VMCI_ERROR_DEVICE_NOT_FOUND; + + if (VMCI_INVALID_ID == src->context) { + /* + * If it came from a guest then it must have a + * valid context. Otherwise we can use the + * host context. + */ + if (from_guest) + return VMCI_ERROR_INVALID_ARGS; + + src->context = VMCI_HOST_CONTEXT_ID; + } + + /* Route to local client. */ + *route = VMCI_ROUTE_AS_HOST; + return VMCI_SUCCESS; + } + + /* + * If we are acting as a host then this might be destined for + * a guest. + */ + if (has_host_device) { + /* It will have a context if it is meant for a guest. */ + if (vmci_ctx_exists(dst->context)) { + if (VMCI_INVALID_ID == src->context) { + /* + * If it came from a guest then it + * must have a valid context. + * Otherwise we can use the host + * context. + */ + + if (from_guest) + return VMCI_ERROR_INVALID_ARGS; + + src->context = VMCI_HOST_CONTEXT_ID; + } else if (VMCI_CONTEXT_IS_VM(src->context) && + src->context != dst->context) { + /* + * VM to VM communication is not + * allowed. Since we catch all + * communication destined for the host + * above, this must be destined for a + * VM since there is a valid context. + */ + + ASSERT(VMCI_CONTEXT_IS_VM(dst->context)); + + return VMCI_ERROR_DST_UNREACHABLE; + } + + /* Pass it up to the guest. */ + *route = VMCI_ROUTE_AS_HOST; + return VMCI_SUCCESS; + } else if (!has_guest_device) { + /* + * The host is attempting to reach a CID + * without an active context, and we can't + * send it down, since we have no guest + * device. + */ + + return VMCI_ERROR_DST_UNREACHABLE; + } + } + + /* + * We must be a guest trying to send to another guest, which means + * we need to send it down to the host. We do not filter out VM to + * VM communication here, since we want to be able to use the guest + * driver on older versions that do support VM to VM communication. + */ + if (!has_guest_device) { + /* + * Ending up here means we have neither guest nor host + * device. That shouldn't happen, since any VMCI + * client in the kernel should have done a successful + * VMCI_DeviceGet. + */ + + ASSERT(false); + return VMCI_ERROR_DEVICE_NOT_FOUND; + } + + /* If no source context then use the current context. */ + if (VMCI_INVALID_ID == src->context) + src->context = vmci_get_context_id(); + + /* + * Send it from local client down to the host, which will + * route it to the other guest for us. + */ + *route = VMCI_ROUTE_AS_GUEST; + return VMCI_SUCCESS; +} diff --git a/drivers/misc/vmw_vmci/vmci_route.h b/drivers/misc/vmw_vmci/vmci_route.h new file mode 100644 index 0000000..3b30e82 --- /dev/null +++ b/drivers/misc/vmw_vmci/vmci_route.h @@ -0,0 +1,30 @@ +/* + * VMware VMCI Driver + * + * Copyright (C) 2012 VMware, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 and no later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#ifndef _VMCI_ROUTE_H_ +#define _VMCI_ROUTE_H_ + +#include + +enum vmci_route { + VMCI_ROUTE_NONE, + VMCI_ROUTE_AS_HOST, + VMCI_ROUTE_AS_GUEST, +}; + +int vmci_route(struct vmci_handle *src, const struct vmci_handle *dst, + bool from_guest, enum vmci_route *route); + +#endif /* _VMCI_ROUTE_H_ */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/