| Message ID | 20200913195348.1064154-4-philmd@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | user-mode: Prune build dependencies (part 2) | expand |
Philippe Mathieu-Daudé <philmd@redhat.com> writes: > Only qemu-system-FOO and qemu-storage-daemon provide QMP > monitors, therefore such declarations and definitions are > irrelevant for user-mode emulation. > > Restricting the balloon-related commands to machine.json > allows pulling less declarations/definitions to user-mode. How this affects user mode is not obvious to (ignorant) me. Can you provide a clue? [...]
+Laurent and David On 9/14/20 11:16 AM, Markus Armbruster wrote: > Philippe Mathieu-Daudé <philmd@redhat.com> writes: > >> Only qemu-system-FOO and qemu-storage-daemon provide QMP >> monitors, therefore such declarations and definitions are >> irrelevant for user-mode emulation. >> >> Restricting the balloon-related commands to machine.json >> allows pulling less declarations/definitions to user-mode. > > How this affects user mode is not obvious to (ignorant) me. Can you > provide a clue? I guess this was discussed with David at some point. Maybe the QMP commands are not exposed via HMP, making this code unreachable? Anyhow user-mode binaries don't use the memory ballooning feature, this is specific to system-mode emulation. Laurent/David, do you have some more trivial explanation? Thanks, Phil.
> Am 14.09.2020 um 11:42 schrieb Philippe Mathieu-Daudé <philmd@redhat.com>: > > +Laurent and David > >> On 9/14/20 11:16 AM, Markus Armbruster wrote: >> Philippe Mathieu-Daudé <philmd@redhat.com> writes: >> >>> Only qemu-system-FOO and qemu-storage-daemon provide QMP >>> monitors, therefore such declarations and definitions are >>> irrelevant for user-mode emulation. >>> >>> Restricting the balloon-related commands to machine.json >>> allows pulling less declarations/definitions to user-mode. >> >> How this affects user mode is not obvious to (ignorant) me. Can you >> provide a clue? > > I guess this was discussed with David at some point. > > Maybe the QMP commands are not exposed via HMP, making this > code unreachable? > > Anyhow user-mode binaries don't use the memory ballooning feature, > this is specific to system-mode emulation. > > Laurent/David, do you have some more trivial explanation? Agreed. No memory ballooning device -> no memory ballooning :) > > Thanks, > > Phil. >
David Hildenbrand <david@redhat.com> writes: >> Am 14.09.2020 um 11:42 schrieb Philippe Mathieu-Daudé <philmd@redhat.com>: >> >> +Laurent and David >> >>> On 9/14/20 11:16 AM, Markus Armbruster wrote: >>> Philippe Mathieu-Daudé <philmd@redhat.com> writes: >>> >>>> Only qemu-system-FOO and qemu-storage-daemon provide QMP >>>> monitors, therefore such declarations and definitions are >>>> irrelevant for user-mode emulation. >>>> >>>> Restricting the balloon-related commands to machine.json >>>> allows pulling less declarations/definitions to user-mode. >>> >>> How this affects user mode is not obvious to (ignorant) me. Can you >>> provide a clue? >> >> I guess this was discussed with David at some point. >> >> Maybe the QMP commands are not exposed via HMP, making this >> code unreachable? >> >> Anyhow user-mode binaries don't use the memory ballooning feature, >> this is specific to system-mode emulation. >> >> Laurent/David, do you have some more trivial explanation? > > Agreed. > > No memory ballooning device -> no memory ballooning :) I understand why user mode doesn't need device models. What I don't understand offhand is how balloon-related stuff in misc.json ends up pulling "declarations/definitions to user-mode". What exactly is being pulled where before the series, and no more afterwards? Is it just the code generated for the QAPI stuff you move, or is it more?
On 9/14/20 1:21 PM, Markus Armbruster wrote: > David Hildenbrand <david@redhat.com> writes: > >>> Am 14.09.2020 um 11:42 schrieb Philippe Mathieu-Daudé <philmd@redhat.com>: >>> >>> +Laurent and David >>> >>>> On 9/14/20 11:16 AM, Markus Armbruster wrote: >>>> Philippe Mathieu-Daudé <philmd@redhat.com> writes: >>>> >>>>> Only qemu-system-FOO and qemu-storage-daemon provide QMP >>>>> monitors, therefore such declarations and definitions are >>>>> irrelevant for user-mode emulation. >>>>> >>>>> Restricting the balloon-related commands to machine.json >>>>> allows pulling less declarations/definitions to user-mode. >>>> >>>> How this affects user mode is not obvious to (ignorant) me. Can you >>>> provide a clue? >>> >>> I guess this was discussed with David at some point. >>> >>> Maybe the QMP commands are not exposed via HMP, making this >>> code unreachable? >>> >>> Anyhow user-mode binaries don't use the memory ballooning feature, >>> this is specific to system-mode emulation. >>> >>> Laurent/David, do you have some more trivial explanation? >> >> Agreed. >> >> No memory ballooning device -> no memory ballooning :) > > I understand why user mode doesn't need device models. What I don't > understand offhand is how balloon-related stuff in misc.json ends up > pulling "declarations/definitions to user-mode". What exactly is being > pulled where before the series, and no more afterwards? > > Is it just the code generated for the QAPI stuff you move, or is it > more? As of this series, this is only QAPI generated code. (code which pulls in unwanted declarations/definitions that should be poisoned, but we can't because of this). I didn't feel the need to enumerate what is removed from user-mode, because from the diff (and no link failure) I thought it was obvious. I can do, but that would be simply copy/pasting the QAPI changes. Part 3 start to remove things, but I kept that separated.
Philippe Mathieu-Daudé <philmd@redhat.com> writes: > On 9/14/20 1:21 PM, Markus Armbruster wrote: >> David Hildenbrand <david@redhat.com> writes: >> >>>> Am 14.09.2020 um 11:42 schrieb Philippe Mathieu-Daudé <philmd@redhat.com>: >>>> >>>> +Laurent and David >>>> >>>>> On 9/14/20 11:16 AM, Markus Armbruster wrote: >>>>> Philippe Mathieu-Daudé <philmd@redhat.com> writes: >>>>> >>>>>> Only qemu-system-FOO and qemu-storage-daemon provide QMP >>>>>> monitors, therefore such declarations and definitions are >>>>>> irrelevant for user-mode emulation. >>>>>> >>>>>> Restricting the balloon-related commands to machine.json >>>>>> allows pulling less declarations/definitions to user-mode. >>>>> >>>>> How this affects user mode is not obvious to (ignorant) me. Can you >>>>> provide a clue? >>>> >>>> I guess this was discussed with David at some point. >>>> >>>> Maybe the QMP commands are not exposed via HMP, making this >>>> code unreachable? >>>> >>>> Anyhow user-mode binaries don't use the memory ballooning feature, >>>> this is specific to system-mode emulation. >>>> >>>> Laurent/David, do you have some more trivial explanation? >>> >>> Agreed. >>> >>> No memory ballooning device -> no memory ballooning :) >> >> I understand why user mode doesn't need device models. What I don't >> understand offhand is how balloon-related stuff in misc.json ends up >> pulling "declarations/definitions to user-mode". What exactly is being >> pulled where before the series, and no more afterwards? >> >> Is it just the code generated for the QAPI stuff you move, or is it >> more? > > As of this series, this is only QAPI generated code. > (code which pulls in unwanted declarations/definitions > that should be poisoned, but we can't because of this). > > I didn't feel the need to enumerate what is removed from > user-mode, because from the diff (and no link failure) > I thought it was obvious. I can do, but that would be > simply copy/pasting the QAPI changes. Suggest to replace "pulling less declarations/definitions to user-mode" by "pulling less QAPI-generated code into user-mode" in all the commit messages. > Part 3 start to remove things, but I kept that separated. That's okay.
diff --git a/qapi/machine.json b/qapi/machine.json index b6396aa3fea..04f0a907c75 100644 --- a/qapi/machine.json +++ b/qapi/machine.json @@ -969,3 +969,93 @@ 'data': 'NumaOptions', 'allow-preconfig': true } + +## +# @balloon: +# +# Request the balloon driver to change its balloon size. +# +# @value: the target logical size of the VM in bytes +# We can deduce the size of the balloon using this formula: +# logical_vm_size = vm_ram_size - balloon_size +# From it we have: balloon_size = vm_ram_size - @value +# +# Returns: - Nothing on success +# - If the balloon driver is enabled but not functional because the KVM +# kernel module cannot support it, KvmMissingCap +# - If no balloon device is present, DeviceNotActive +# +# Notes: This command just issues a request to the guest. When it returns, +# the balloon size may not have changed. A guest can change the balloon +# size independent of this command. +# +# Since: 0.14.0 +# +# Example: +# +# -> { "execute": "balloon", "arguments": { "value": 536870912 } } +# <- { "return": {} } +# +# With a 2.5GiB guest this command inflated the ballon to 3GiB. +# +## +{ 'command': 'balloon', 'data': {'value': 'int'} } + +## +# @BalloonInfo: +# +# Information about the guest balloon device. +# +# @actual: the logical size of the VM in bytes +# Formula used: logical_vm_size = vm_ram_size - balloon_size +# +# Since: 0.14.0 +# +## +{ 'struct': 'BalloonInfo', 'data': {'actual': 'int' } } + +## +# @query-balloon: +# +# Return information about the balloon device. +# +# Returns: - @BalloonInfo on success +# - If the balloon driver is enabled but not functional because the KVM +# kernel module cannot support it, KvmMissingCap +# - If no balloon device is present, DeviceNotActive +# +# Since: 0.14.0 +# +# Example: +# +# -> { "execute": "query-balloon" } +# <- { "return": { +# "actual": 1073741824, +# } +# } +# +## +{ 'command': 'query-balloon', 'returns': 'BalloonInfo' } + +## +# @BALLOON_CHANGE: +# +# Emitted when the guest changes the actual BALLOON level. This value is +# equivalent to the @actual field return by the 'query-balloon' command +# +# @actual: the logical size of the VM in bytes +# Formula used: logical_vm_size = vm_ram_size - balloon_size +# +# Note: this event is rate-limited. +# +# Since: 1.2 +# +# Example: +# +# <- { "event": "BALLOON_CHANGE", +# "data": { "actual": 944766976 }, +# "timestamp": { "seconds": 1267020223, "microseconds": 435656 } } +# +## +{ 'event': 'BALLOON_CHANGE', + 'data': { 'actual': 'int' } } diff --git a/qapi/misc.json b/qapi/misc.json index a667fdf03e5..7a14c50094d 100644 --- a/qapi/misc.json +++ b/qapi/misc.json @@ -187,65 +187,6 @@ { 'command': 'query-iothreads', 'returns': ['IOThreadInfo'], 'allow-preconfig': true } -## -# @BalloonInfo: -# -# Information about the guest balloon device. -# -# @actual: the logical size of the VM in bytes -# Formula used: logical_vm_size = vm_ram_size - balloon_size -# -# Since: 0.14.0 -# -## -{ 'struct': 'BalloonInfo', 'data': {'actual': 'int' } } - -## -# @query-balloon: -# -# Return information about the balloon device. -# -# Returns: - @BalloonInfo on success -# - If the balloon driver is enabled but not functional because the KVM -# kernel module cannot support it, KvmMissingCap -# - If no balloon device is present, DeviceNotActive -# -# Since: 0.14.0 -# -# Example: -# -# -> { "execute": "query-balloon" } -# <- { "return": { -# "actual": 1073741824, -# } -# } -# -## -{ 'command': 'query-balloon', 'returns': 'BalloonInfo' } - -## -# @BALLOON_CHANGE: -# -# Emitted when the guest changes the actual BALLOON level. This value is -# equivalent to the @actual field return by the 'query-balloon' command -# -# @actual: the logical size of the VM in bytes -# Formula used: logical_vm_size = vm_ram_size - balloon_size -# -# Note: this event is rate-limited. -# -# Since: 1.2 -# -# Example: -# -# <- { "event": "BALLOON_CHANGE", -# "data": { "actual": 944766976 }, -# "timestamp": { "seconds": 1267020223, "microseconds": 435656 } } -# -## -{ 'event': 'BALLOON_CHANGE', - 'data': { 'actual': 'int' } } - ## # @PciMemoryRange: # @@ -756,37 +697,6 @@ ## { 'command': 'inject-nmi' } -## -# @balloon: -# -# Request the balloon driver to change its balloon size. -# -# @value: the target logical size of the VM in bytes -# We can deduce the size of the balloon using this formula: -# logical_vm_size = vm_ram_size - balloon_size -# From it we have: balloon_size = vm_ram_size - @value -# -# Returns: - Nothing on success -# - If the balloon driver is enabled but not functional because the KVM -# kernel module cannot support it, KvmMissingCap -# - If no balloon device is present, DeviceNotActive -# -# Notes: This command just issues a request to the guest. When it returns, -# the balloon size may not have changed. A guest can change the balloon -# size independent of this command. -# -# Since: 0.14.0 -# -# Example: -# -# -> { "execute": "balloon", "arguments": { "value": 536870912 } } -# <- { "return": {} } -# -# With a 2.5GiB guest this command inflated the balloon to 3GiB. -# -## -{ 'command': 'balloon', 'data': {'value': 'int'} } - ## # @human-monitor-command: # diff --git a/include/sysemu/balloon.h b/include/sysemu/balloon.h index 20a2defe3aa..867687b73ac 100644 --- a/include/sysemu/balloon.h +++ b/include/sysemu/balloon.h @@ -15,7 +15,7 @@ #define QEMU_BALLOON_H #include "exec/cpu-common.h" -#include "qapi/qapi-types-misc.h" +#include "qapi/qapi-types-machine.h" typedef void (QEMUBalloonEvent)(void *opaque, ram_addr_t target); typedef void (QEMUBalloonStatus)(void *opaque, BalloonInfo *info); diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 22cb5df717b..b22b5beda3c 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -24,7 +24,7 @@ #include "hw/virtio/virtio-balloon.h" #include "exec/address-spaces.h" #include "qapi/error.h" -#include "qapi/qapi-events-misc.h" +#include "qapi/qapi-events-machine.h" #include "qapi/visitor.h" #include "trace.h" #include "qemu/error-report.h" diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index 7711726fd22..de01ba20845 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -32,6 +32,7 @@ #include "qapi/qapi-commands-block.h" #include "qapi/qapi-commands-char.h" #include "qapi/qapi-commands-control.h" +#include "qapi/qapi-commands-machine.h" #include "qapi/qapi-commands-migration.h" #include "qapi/qapi-commands-misc.h" #include "qapi/qapi-commands-net.h" diff --git a/softmmu/balloon.c b/softmmu/balloon.c index 23452295cd9..e0e8969a4b9 100644 --- a/softmmu/balloon.c +++ b/softmmu/balloon.c @@ -29,7 +29,7 @@ #include "sysemu/kvm.h" #include "sysemu/balloon.h" #include "qapi/error.h" -#include "qapi/qapi-commands-misc.h" +#include "qapi/qapi-commands-machine.h" #include "qapi/qmp/qerror.h" #include "trace.h"