From patchwork Wed Jan 11 23:56:05 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 135572 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 585A5B6EEA for ; Thu, 12 Jan 2012 16:45:47 +1100 (EST) Received: from localhost ([::1]:56139 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RlDTq-0005Ve-Gi for incoming@patchwork.ozlabs.org; Thu, 12 Jan 2012 00:45:42 -0500 Received: from eggs.gnu.org ([140.186.70.92]:54441) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Rl81r-00066J-Rk for qemu-devel@nongnu.org; Wed, 11 Jan 2012 18:56:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Rl81q-0001Rj-FF for qemu-devel@nongnu.org; Wed, 11 Jan 2012 18:56:27 -0500 Received: from mout.perfora.net ([74.208.4.195]:49304) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Rl81q-0001Re-5S for qemu-devel@nongnu.org; Wed, 11 Jan 2012 18:56:26 -0500 Received: from illuin.austin.ibm.com ([32.97.110.59]) by mrelay.perfora.net (node=mrus4) with ESMTP (Nemesis) id 0MI5e2-1RhIGm1Q2o-004Dqq; Wed, 11 Jan 2012 18:56:18 -0500 From: Michael Roth To: qemu-devel@nongnu.org Date: Wed, 11 Jan 2012 17:56:05 -0600 Message-Id: <1326326165-23201-1-git-send-email-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1326325801-22825-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1326325801-22825-1-git-send-email-mdroth@linux.vnet.ibm.com> X-Provags-ID: V02:K0:M23agtFgDV9Kl6j1y3p9hMAHzw0vCYbcfX9Pbd8dufz FoGVamcN9820xqP33BBvfmIafqcUTh/d9TrBHvLGa+68PO9j4/ RC/b6L6UcZAmR7+v+TBe6Fz6FDVLuUB0ZZBPmuPF1gOKa4aliT 2LuDhVWQip1hgIRWEMLUpmhSGF8GRFzQqM8WxNK5zpb8R1POc7 cpTNlmVddfPBE/zGvCQOI1NoPevrz2tnXw7yTkYBJA3xyvGF7m Mo+jk59FkvY2E+6sXtEQEyXaDhqLNy/bxIxTbFFTjPci7zzVWj p6BqvDPrr4plecQuMOpRXAD54H+uqP9XXpRxF2we7LdmfL8uX4 5OLTboELdzKwsfarzMLpEqHmLosk0UkJsRCwLHepUPemtgOKBk XT6aXhrwqy/+DkYZTtXL6YH0dzL1C/LJE8= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 74.208.4.195 X-Mailman-Approved-At: Thu, 12 Jan 2012 00:44:50 -0500 Cc: aliguori@us.ibm.com, mdroth@linux.vnet.ibm.com, lcapitulino@redhat.com Subject: [Qemu-devel] [PATCH v2] qemu-ga: add guest-set-support-level command X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Recently commands where introduced on the mailing that involved adding commands to the guest agent that could potentially break older versions of QEMU. While it's okay to expect that qemu-ga can be updated to support newer host features, it's unrealistic to require a host to be updated to support qemu-ga features, or to expect that qemu-ga should be downgraded in these circumstances, especially considering that a large mix of guests/agents may be running on a particular host. To address this, we introduce here a mechanism to set qemu-ga's feature-set to one that is known to be compatible with the host/QEMU running the guest. As new commands/options are added, we can maintain backward-compatibility by adding conditional checks to filter out host-incompatible functionality based on the host-specified support level (generally analogous to the host QEMU version) set by the client. The current default/minimum support level supports all versions of QEMU that have had qemu-ga in-tree (0.15.0, 1.0.0) and so should be backward-compatible with existing hosts/clients. Signed-off-by: Michael Roth --- qapi-schema-guest.json | 31 ++++++++++++++++++++++++++++- qemu-ga.c | 46 ++++++++++++++++++++++++++++++++++++++++++++ qga/guest-agent-commands.c | 13 ++++++++++++ qga/guest-agent-core.h | 11 ++++++++++ 4 files changed, 100 insertions(+), 1 deletions(-) diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json index 5f8a18d..32bc041 100644 --- a/qapi-schema-guest.json +++ b/qapi-schema-guest.json @@ -43,15 +43,44 @@ # # Since: 0.15.0 ## +{ 'type': 'GuestAgentSupportLevel', + 'data': { 'major': 'int', 'minor': 'int', 'micro': 'int' } } { 'type': 'GuestAgentCommandInfo', 'data': { 'name': 'str', 'enabled': 'bool' } } { 'type': 'GuestAgentInfo', 'data': { 'version': 'str', - 'supported_commands': ['GuestAgentCommandInfo'] } } + 'supported_commands': ['GuestAgentCommandInfo'] + 'support_level': 'GuestAgentSupportLevel' } } { 'command': 'guest-info', 'returns': 'GuestAgentInfo' } ## +# @guest-set-support-level: +# +# Set guest agent feature-set to one that is compatible with/supported by +# the host. +# +# Certain commands/options may have dependencies on host +# version/support-level, such as specific QEMU features (such +# dependencies will be noted in this schema). By default we assume 1.0.0, +# which is backward-compatible with QEMU 0.15.0/1.0, and should be compatible +# with later versions of QEMU as well. To enable newer guest agent features, +# this command must be issued to raise the support-level to one corresponding +# to supported host QEMU/KVM/etc capabilities. +# +# The currently set support level is obtainable via the guest-info command. +# +# @level: Desired host support-level, generally <= host QEMU version +# level. Note that undefined behavior may occur if a support-level is +# provided that exceeds the capabilities of the version of QEMU currently +# running the guest. +# +# Returns: Nothing on success +# +{ 'command': 'guest-set-support-level', + 'data': { 'major': 'int', 'minor': 'int', '*micro': 'int' } } + +## # @guest-shutdown: # # Initiate guest-activated shutdown. Note: this is an asynchronous diff --git a/qemu-ga.c b/qemu-ga.c index 200bb15..6840233 100644 --- a/qemu-ga.c +++ b/qemu-ga.c @@ -28,6 +28,7 @@ #include "qerror.h" #include "error_int.h" #include "qapi/qmp-core.h" +#include "qga-qapi-types.h" #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0" #define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid" @@ -102,6 +103,45 @@ static void usage(const char *cmd) static void conn_channel_close(GAState *s); +static GuestAgentSupportLevel ga_support_level; + +static int ga_cmp_support_levels(GuestAgentSupportLevel a, + GuestAgentSupportLevel b) +{ + if (a.major == b.major) { + if (a.minor == b.minor) { + return a.micro - b.micro; + } + return a.minor - b.minor; + } + return a.major - b.major; +} + +bool ga_has_support_level(int major, int minor, int micro) +{ + GuestAgentSupportLevel level = { major, minor, micro }; + return ga_cmp_support_levels(level, ga_support_level) >= 0; +} + +void ga_set_support_level(GuestAgentSupportLevel level) +{ + GuestAgentSupportLevel min_support_level = { + QGA_SUPPORT_LEVEL_MAJOR_MIN, + QGA_SUPPORT_LEVEL_MINOR_MIN, + QGA_SUPPORT_LEVEL_MICRO_MIN + }; + if (ga_cmp_support_levels(level, min_support_level) <= 0) { + ga_support_level = min_support_level; + } else { + ga_support_level = level; + } +} + +GuestAgentSupportLevel ga_get_support_level(void) +{ + return ga_support_level; +} + static const char *ga_log_level_str(GLogLevelFlags level) { switch (level & G_LOG_LEVEL_MASK) { @@ -569,6 +609,11 @@ int main(int argc, char **argv) GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL; FILE *log_file = stderr; GAState *s; + GuestAgentSupportLevel default_support_level = { + QGA_SUPPORT_LEVEL_MAJOR_DEFAULT, + QGA_SUPPORT_LEVEL_MINOR_DEFAULT, + QGA_SUPPORT_LEVEL_MICRO_DEFAULT + }; module_call_init(MODULE_INIT_QAPI); @@ -642,6 +687,7 @@ int main(int argc, char **argv) become_daemon(pidfile); } + ga_set_support_level(default_support_level); s = g_malloc0(sizeof(GAState)); s->conn_channel = NULL; s->path = path; diff --git a/qga/guest-agent-commands.c b/qga/guest-agent-commands.c index a09c8ca..656dde8 100644 --- a/qga/guest-agent-commands.c +++ b/qga/guest-agent-commands.c @@ -62,6 +62,8 @@ struct GuestAgentInfo *qmp_guest_info(Error **err) char **cmd_list_head, **cmd_list; info->version = g_strdup(QGA_VERSION); + info->support_level = g_malloc0(sizeof(GuestAgentSupportLevel)); + *info->support_level = ga_get_support_level(); cmd_list_head = cmd_list = qmp_get_command_list(); if (*cmd_list_head == NULL) { @@ -87,6 +89,17 @@ out: return info; } +void qmp_guest_set_support_level(int64_t major, int64_t minor, bool has_micro, + int64_t micro, Error **errp) +{ + GuestAgentSupportLevel level = { + major, + minor, + has_micro ? micro : 0 + }; + ga_set_support_level(level); +} + void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err) { int ret; diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h index e42b91d..7327e73 100644 --- a/qga/guest-agent-core.h +++ b/qga/guest-agent-core.h @@ -12,8 +12,16 @@ */ #include "qapi/qmp-core.h" #include "qemu-common.h" +#include "qga-qapi-types.h" #define QGA_VERSION "1.0" +#define QGA_SUPPORT_LEVEL_MAJOR_DEFAULT 1 +#define QGA_SUPPORT_LEVEL_MINOR_DEFAULT 0 +#define QGA_SUPPORT_LEVEL_MICRO_DEFAULT 0 +/* lowest possible support level */ +#define QGA_SUPPORT_LEVEL_MAJOR_MIN 1 +#define QGA_SUPPORT_LEVEL_MINOR_MIN 0 +#define QGA_SUPPORT_LEVEL_MICRO_MIN 0 #define QGA_READ_COUNT_DEFAULT 4 << 10 typedef struct GAState GAState; @@ -29,3 +37,6 @@ GACommandState *ga_command_state_new(void); bool ga_logging_enabled(GAState *s); void ga_disable_logging(GAState *s); void ga_enable_logging(GAState *s); +bool ga_has_support_level(int major, int minor, int micro); +void ga_set_support_level(GuestAgentSupportLevel level); +GuestAgentSupportLevel ga_get_support_level(void);