src/libvirt_private.syms | 1 + src/qemu/qemu_command.c | 2 ++ src/qemu/qemu_domain.c | 36 +++++++++++++++++++++++++++++++ src/qemu/qemu_domain.h | 4 ++++ src/qemu/qemu_hotplug.c | 2 ++ src/util/virnetdev.c | 46 ++++++++++++++++++++++++++++++++++++++++ src/util/virnetdev.h | 3 +++ 7 files changed, 94 insertions(+)
See 2/2 for detailed explanation. Long story short - we can squeeze more bandwidth from TAP devices we create for domains. Michal Prívozník (2): virnetdev: Introduce virNetDevSetRootQDisc() qemu: Set noqueue qdisc for TAP devices src/libvirt_private.syms | 1 + src/qemu/qemu_command.c | 2 ++ src/qemu/qemu_domain.c | 36 +++++++++++++++++++++++++++++++ src/qemu/qemu_domain.h | 4 ++++ src/qemu/qemu_hotplug.c | 2 ++ src/util/virnetdev.c | 46 ++++++++++++++++++++++++++++++++++++++++ src/util/virnetdev.h | 3 +++ 7 files changed, 94 insertions(+) -- 2.26.2
On 10/8/20 3:10 PM, Michal Privoznik wrote: > See 2/2 for detailed explanation. > Long story short - we can squeeze more bandwidth from TAP devices we > create for domains. > > Michal Prívozník (2): > virnetdev: Introduce virNetDevSetRootQDisc() > qemu: Set noqueue qdisc for TAP devices Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com> Have you tried it out with older kernels? Reading the bug I understood that 4.2 and older (2015 kernels) does not have qdisc support and that you can, for example, test for NETIF_F_LLTX of the ETHTOOL_GFEATURES ioctl to verify it. I consider this to be a 'nice to have' that can be added in a follow up patch though, if applicable. By the way, do we have any documentation about "the latest Libvirt release will not care about N+ years old kernel/QEMU"? Thanks, DHB > > src/libvirt_private.syms | 1 + > src/qemu/qemu_command.c | 2 ++ > src/qemu/qemu_domain.c | 36 +++++++++++++++++++++++++++++++ > src/qemu/qemu_domain.h | 4 ++++ > src/qemu/qemu_hotplug.c | 2 ++ > src/util/virnetdev.c | 46 ++++++++++++++++++++++++++++++++++++++++ > src/util/virnetdev.h | 3 +++ > 7 files changed, 94 insertions(+) >
On 10/13/20 3:09 PM, Daniel Henrique Barboza wrote:
>
>
> On 10/8/20 3:10 PM, Michal Privoznik wrote:
>> See 2/2 for detailed explanation.
>> Long story short - we can squeeze more bandwidth from TAP devices we
>> create for domains.
>>
>> Michal Prívozník (2):
>> virnetdev: Introduce virNetDevSetRootQDisc()
>> qemu: Set noqueue qdisc for TAP devices
>
>
> Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
>
Thanks. Just before I merged these I realized that it will be a good
idea to mock virNetDevSetRootQDisc() so that we don't run tc from the
test suite. But the diff is really trivial:
diff --git i/src/util/virnetdev.h w/src/util/virnetdev.h
index 82943b8e08..dfef49938f 100644
--- i/src/util/virnetdev.h
+++ w/src/util/virnetdev.h
@@ -313,6 +313,7 @@ int virNetDevRunEthernetScript(const char *ifname,
const char *script)
G_GNUC_NO_INLINE;
int virNetDevSetRootQDisc(const char *ifname,
- const char *qdisc);
+ const char *qdisc)
+ G_GNUC_NO_INLINE;
G_DEFINE_AUTOPTR_CLEANUP_FUNC(virNetDevRxFilter, virNetDevRxFilterFree);
diff --git i/tests/qemuxml2argvmock.c w/tests/qemuxml2argvmock.c
index 9bf4357b66..b9322f4f2a 100644
--- i/tests/qemuxml2argvmock.c
+++ w/tests/qemuxml2argvmock.c
@@ -286,3 +286,11 @@ qemuBuildTPMOpenBackendFDs(const char *tpmdev
G_GNUC_UNUSED,
*cancelfd = 1731;
return 0;
}
+
+
+int
+virNetDevSetRootQDisc(const char *ifname G_GNUC_UNUSED,
+ const char *qdisc G_GNUC_UNUSED)
+{
+ return 0;
+}
Hopefully, you are okay if I squash this to 2/2.
>
> Have you tried it out with older kernels? Reading the bug I understood
> that 4.2 and older (2015 kernels) does not have qdisc support and that you
> can, for example, test for NETIF_F_LLTX of the ETHTOOL_GFEATURES ioctl to
> verify it.
>
I didn't, but I had this on mind when writing patches and I made the
whole thing best effort. Note that qemuDomainInterfaceSetDefaultQDisc()
retval is not checked for => if setting noqueue fails (for whatever
reason) then worst case scenario an error is printed into logs.
> I consider this to be a 'nice to have' that can be added in a follow up
> patch though, if applicable. By the way, do we have any documentation about
> "the latest Libvirt release will not care about N+ years old kernel/QEMU"?
I'm not sure what you mean. This perhaps?
https://libvirt.org/platforms.html#linux-freebsd-and-macos
Michal
On 10/13/20 11:06 AM, Michal Privoznik wrote:
> On 10/13/20 3:09 PM, Daniel Henrique Barboza wrote:
>>
>>
>> On 10/8/20 3:10 PM, Michal Privoznik wrote:
>>> See 2/2 for detailed explanation.
>>> Long story short - we can squeeze more bandwidth from TAP devices we
>>> create for domains.
>>>
>>> Michal Prívozník (2):
>>> virnetdev: Introduce virNetDevSetRootQDisc()
>>> qemu: Set noqueue qdisc for TAP devices
>>
>>
>> Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
>>
>
> Thanks. Just before I merged these I realized that it will be a good idea to mock virNetDevSetRootQDisc() so that we don't run tc from the test suite. But the diff is really trivial:
>
> diff --git i/src/util/virnetdev.h w/src/util/virnetdev.h
> index 82943b8e08..dfef49938f 100644
> --- i/src/util/virnetdev.h
> +++ w/src/util/virnetdev.h
> @@ -313,6 +313,7 @@ int virNetDevRunEthernetScript(const char *ifname, const char *script)
> G_GNUC_NO_INLINE;
>
> int virNetDevSetRootQDisc(const char *ifname,
> - const char *qdisc);
> + const char *qdisc)
> + G_GNUC_NO_INLINE;
>
> G_DEFINE_AUTOPTR_CLEANUP_FUNC(virNetDevRxFilter, virNetDevRxFilterFree);
> diff --git i/tests/qemuxml2argvmock.c w/tests/qemuxml2argvmock.c
> index 9bf4357b66..b9322f4f2a 100644
> --- i/tests/qemuxml2argvmock.c
> +++ w/tests/qemuxml2argvmock.c
> @@ -286,3 +286,11 @@ qemuBuildTPMOpenBackendFDs(const char *tpmdev G_GNUC_UNUSED,
> *cancelfd = 1731;
> return 0;
> }
> +
> +
> +int
> +virNetDevSetRootQDisc(const char *ifname G_GNUC_UNUSED,
> + const char *qdisc G_GNUC_UNUSED)
> +{
> + return 0;
> +}
>
>
> Hopefully, you are okay if I squash this to 2/2.
Yep, go ahead.
>
>>
>> Have you tried it out with older kernels? Reading the bug I understood
>> that 4.2 and older (2015 kernels) does not have qdisc support and that you
>> can, for example, test for NETIF_F_LLTX of the ETHTOOL_GFEATURES ioctl to
>> verify it.
>>
>
> I didn't, but I had this on mind when writing patches and I made the whole thing best effort. Note that qemuDomainInterfaceSetDefaultQDisc() retval is not checked for => if setting noqueue fails (for whatever reason) then worst case scenario an error is printed into logs.
>
>> I consider this to be a 'nice to have' that can be added in a follow up
>> patch though, if applicable. By the way, do we have any documentation about
>> "the latest Libvirt release will not care about N+ years old kernel/QEMU"?
>
> I'm not sure what you mean. This perhaps?
>
> https://libvirt.org/platforms.html#linux-freebsd-and-macos
Thanks, this is what I was looking for.
DHB
>
> Michal
>
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