From: Tao Xu <tao3.xu@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
rkrcmar@redhat.com, sean.j.christopherson@intel.com,
corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, hpa@zytor.com
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jingqi.liu@intel.com
Subject: Re: [PATCH v8 0/3] KVM: x86: Enable user wait instructions
Date: Mon, 16 Sep 2019 09:28:06 +0800 [thread overview]
Message-ID: <ca969df2-a42a-3e7c-f49c-6b59d097b3de@intel.com> (raw)
In-Reply-To: <ad687740-1525-f9c2-b441-63613b7dd93e@redhat.com>
On 7/20/2019 1:18 AM, Paolo Bonzini wrote:
> On 19/07/19 08:31, Tao Xu wrote:
>> Ping for comments :)
>
> Hi, I'll look at it for 5.4, right after the merge window.
>
> Paolo
>
Hi paolo,
Linux 5.3 has released, could you review these patches. Thank you very much!
Tao
>> On 7/16/2019 2:55 PM, Tao Xu wrote:
>>> UMONITOR, UMWAIT and TPAUSE are a set of user wait instructions.
>>>
>>> UMONITOR arms address monitoring hardware using an address. A store
>>> to an address within the specified address range triggers the
>>> monitoring hardware to wake up the processor waiting in umwait.
>>>
>>> UMWAIT instructs the processor to enter an implementation-dependent
>>> optimized state while monitoring a range of addresses. The optimized
>>> state may be either a light-weight power/performance optimized state
>>> (c0.1 state) or an improved power/performance optimized state
>>> (c0.2 state).
>>>
>>> TPAUSE instructs the processor to enter an implementation-dependent
>>> optimized state c0.1 or c0.2 state and wake up when time-stamp counter
>>> reaches specified timeout.
>>>
>>> Availability of the user wait instructions is indicated by the presence
>>> of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5].
>>>
>>> The patches enable the umonitor, umwait and tpause features in KVM.
>>> Because umwait and tpause can put a (psysical) CPU into a power saving
>>> state, by default we dont't expose it to kvm and enable it only when
>>> guest CPUID has it. If the instruction causes a delay, the amount
>>> of time delayed is called here the physical delay. The physical delay is
>>> first computed by determining the virtual delay (the time to delay
>>> relative to the VM’s timestamp counter).
>>>
>>> The release document ref below link:
>>> Intel 64 and IA-32 Architectures Software Developer's Manual,
>>> https://software.intel.com/sites/default/files/\
>>> managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf
>>>
>>> Changelog:
>>> v8:
>>> Add vmx_waitpkg_supported() helper (Sean)
>>> Add an accessor to expose umwait_control_cached (Sean)
>>> Set msr_ia32_umwait_control in vcpu_vmx u32 and raise #GP when
>>> [63:32] is set when rdmsr. (Sean)
>>> Introduce a common exit helper handle_unexpected_vmexit (Sean)
>>> v7:
>>> Add nested support for user wait instructions (Paolo)
>>> Use the test on vmx->secondary_exec_control to replace
>>> guest_cpuid_has (Paolo)
>>> v6:
>>> add check msr_info->host_initiated in get/set msr(Xiaoyao)
>>> restore the atomic_switch_umwait_control_msr()(Xiaoyao)
>>>
>>> Tao Xu (3):
>>> KVM: x86: Add support for user wait instructions
>>> KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL
>>> KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit
>>>
>>> arch/x86/include/asm/vmx.h | 1 +
>>> arch/x86/include/uapi/asm/vmx.h | 6 ++-
>>> arch/x86/kernel/cpu/umwait.c | 6 +++
>>> arch/x86/kvm/cpuid.c | 2 +-
>>> arch/x86/kvm/vmx/capabilities.h | 6 +++
>>> arch/x86/kvm/vmx/nested.c | 5 ++
>>> arch/x86/kvm/vmx/vmx.c | 83 ++++++++++++++++++++++++++-------
>>> arch/x86/kvm/vmx/vmx.h | 9 ++++
>>> arch/x86/kvm/x86.c | 1 +
>>> 9 files changed, 101 insertions(+), 18 deletions(-)
>>>
>>
>
next prev parent reply other threads:[~2019-09-16 1:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-16 6:55 [PATCH v8 0/3] KVM: x86: Enable user wait instructions Tao Xu
2019-07-16 6:55 ` [PATCH v8 1/3] KVM: x86: Add support for " Tao Xu
2019-07-16 6:55 ` [PATCH v8 2/3] KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL Tao Xu
2019-07-16 6:55 ` [PATCH v8 3/3] KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit Tao Xu
2019-07-19 6:31 ` [PATCH v8 0/3] KVM: x86: Enable user wait instructions Tao Xu
2019-07-19 17:18 ` Paolo Bonzini
2019-07-20 7:14 ` Tao Xu
2019-09-16 1:28 ` Tao Xu [this message]
2019-09-17 17:05 ` Paolo Bonzini
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