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From: Zhao Liu <zhao1.liu@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Richard Henderson <richard.henderson@linaro.org>,
	Eduardo Habkost <eduardo@habkost.net>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Igor Mammedov <imammedo@redhat.com>,
	Tim Wiederhake <twiederh@redhat.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org,
	Zhao Liu <zhao1.liu@intel.com>
Subject: [PATCH for-9.1 0/7] target/i386/kvm: Cleanup the kvmclock feature name
Date: Fri, 29 Mar 2024 18:19:47 +0800	[thread overview]
Message-ID: <20240329101954.3954987-1-zhao1.liu@linux.intel.com> (raw)

From: Zhao Liu <zhao1.liu@intel.com>

Hi list,

This series is based on Paolo's guest_phys_bits patchset [1].

Currently, the old and new kvmclocks have the same feature name
"kvmclock" in FeatureWordInfo[FEAT_KVM].

When I tried to dig into the history of this unusual naming and fix it,
I realized that Tim was already trying to rename it, so I picked up his
renaming patch [2] (with a new commit message and other minor changes).

13 years age, the same name was introduced in [3], and its main purpose
is to make it easy for users to enable/disable 2 kvmclocks. Then, in
2012, Don tried to rename the new kvmclock, but the follow-up did not
address Igor and Eduardo's comments about compatibility.

Tim [2], not long ago, and I just now, were both puzzled by the naming
one after the other.

So, this series is to push for renaming the new kvmclock feature to
"kvmclock2" and adding compatibility support for older machines (PC 9.0
and older).

Finally, let's put an end to decades of doubt about this name.


Next Step
=========

This series just separates the two kvmclocks from the naming, and in
subsequent patches I plan to stop setting kvmclock(old kcmclock) by
default as long as KVM supports kvmclock2 (new kvmclock).

Also, try to deprecate the old kvmclock in KVM side.

[1]: https://lore.kernel.org/qemu-devel/20240325141422.1380087-1-pbonzini@redhat.com/
[2]: https://lore.kernel.org/qemu-devel/20230908124534.25027-4-twiederh@redhat.com/
[3]: https://lore.kernel.org/qemu-devel/1300401727-5235-3-git-send-email-glommer@redhat.com/
[4]: https://lore.kernel.org/qemu-devel/1348171412-23669-3-git-send-email-Don@CloudSwitch.com/

Thanks and Best Regards,
Zhao

---
Tim Wiederhake (1):
  target/i386: Fix duplicated kvmclock name in FEAT_KVM

Zhao Liu (6):
  target/i386/kvm: Add feature bit definitions for KVM CPUID
  target/i386/kvm: Remove local MSR_KVM_WALL_CLOCK and
    MSR_KVM_SYSTEM_TIME definitions
  target/i386/kvm: Only Save/load kvmclock MSRs when kvmclock enabled
  target/i386/kvm: Save/load MSRs of new kvmclock
    (KVM_FEATURE_CLOCKSOURCE2)
  target/i386/kvm: Add legacy_kvmclock cpu property
  target/i386/kvm: Update comment in kvm_cpu_realizefn()

 hw/i386/kvm/clock.c       |  5 ++--
 hw/i386/pc.c              |  1 +
 target/i386/cpu.c         |  3 +-
 target/i386/cpu.h         | 32 +++++++++++++++++++++
 target/i386/kvm/kvm-cpu.c | 25 ++++++++++++++++-
 target/i386/kvm/kvm.c     | 59 +++++++++++++++++++++++++--------------
 6 files changed, 99 insertions(+), 26 deletions(-)

-- 
2.34.1


             reply	other threads:[~2024-03-29 10:06 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-29 10:19 Zhao Liu [this message]
2024-03-29 10:19 ` [PATCH for-9.1 1/7] target/i386/kvm: Add feature bit definitions for KVM CPUID Zhao Liu
2024-04-24 11:25   ` Xiaoyao Li
2024-03-29 10:19 ` [PATCH for-9.1 2/7] target/i386/kvm: Remove local MSR_KVM_WALL_CLOCK and MSR_KVM_SYSTEM_TIME definitions Zhao Liu
2024-04-24 15:11   ` Xiaoyao Li
2024-03-29 10:19 ` [PATCH for-9.1 3/7] target/i386/kvm: Only Save/load kvmclock MSRs when kvmclock enabled Zhao Liu
2024-03-29 10:19 ` [PATCH for-9.1 4/7] target/i386/kvm: Save/load MSRs of new kvmclock (KVM_FEATURE_CLOCKSOURCE2) Zhao Liu
2024-03-29 10:19 ` [PATCH for-9.1 5/7] target/i386/kvm: Add legacy_kvmclock cpu property Zhao Liu
2024-03-29 10:19 ` [PATCH for-9.1 6/7] target/i386: Fix duplicated kvmclock name in FEAT_KVM Zhao Liu
2024-03-29 10:19 ` [PATCH for-9.1 7/7] target/i386/kvm: Update comment in kvm_cpu_realizefn() Zhao Liu
2024-04-24 10:33 ` [PATCH for-9.1 0/7] target/i386/kvm: Cleanup the kvmclock feature name Zhao Liu
2024-04-24 15:57 ` Xiaoyao Li
2024-04-25  7:17   ` Zhao Liu
2024-04-25  8:40     ` Xiaoyao Li
2024-04-25 10:29       ` Zhao Liu
2024-04-25 12:04         ` Xiaoyao Li
2024-04-25 13:36           ` Zhao Liu

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