kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: Reiji Watanabe <reijiw@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Xiaoyao Li <xiaoyao.li@intel.com>
Subject: Re: [PATCH 09/15] KVM: VMX: Use flag to indicate "active" uret MSRs instead of sorting list
Date: Mon, 10 May 2021 16:43:50 +0000	[thread overview]
Message-ID: <YJlixiTcwFkrnxIL@google.com> (raw)
In-Reply-To: <CAAeT=FyKjHykGNcQc=toqvhCR281SWc6UqNihsjyU+vuo3z5Yg@mail.gmail.com>

On Fri, May 07, 2021, Reiji Watanabe wrote:
> > -static void vmx_setup_uret_msr(struct vcpu_vmx *vmx, unsigned int msr)
> > +static void vmx_setup_uret_msr(struct vcpu_vmx *vmx, unsigned int msr,
> > +                              bool load_into_hardware)
> >  {
> > -       struct vmx_uret_msr tmp;
> > -       int from, to;
> > +       struct vmx_uret_msr *uret_msr;
> >
> > -       from = __vmx_find_uret_msr(vmx, msr);
> > -       if (from < 0)
> > +       uret_msr = vmx_find_uret_msr(vmx, msr);
> > +       if (!uret_msr)
> >                 return;
> > -       to = vmx->nr_active_uret_msrs++;
> >
> > -       tmp = vmx->guest_uret_msrs[to];
> > -       vmx->guest_uret_msrs[to] = vmx->guest_uret_msrs[from];
> > -       vmx->guest_uret_msrs[from] = tmp;
> > +       uret_msr->load_into_hardware = load_into_hardware;
> >  }
> >
> >  /*
> > @@ -1785,30 +1781,36 @@ static void vmx_setup_uret_msr(struct vcpu_vmx *vmx, unsigned int msr)
> >   */
> >  static void setup_msrs(struct vcpu_vmx *vmx)
> >  {
> > -       vmx->guest_uret_msrs_loaded = false;
> > -       vmx->nr_active_uret_msrs = 0;
> >  #ifdef CONFIG_X86_64
> > +       bool load_syscall_msrs;
> > +
> >         /*
> >          * The SYSCALL MSRs are only needed on long mode guests, and only
> >          * when EFER.SCE is set.
> >          */
> > -       if (is_long_mode(&vmx->vcpu) && (vmx->vcpu.arch.efer & EFER_SCE)) {
> > -               vmx_setup_uret_msr(vmx, MSR_STAR);
> > -               vmx_setup_uret_msr(vmx, MSR_LSTAR);
> > -               vmx_setup_uret_msr(vmx, MSR_SYSCALL_MASK);
> > -       }
> > +       load_syscall_msrs = is_long_mode(&vmx->vcpu) &&
> > +                           (vmx->vcpu.arch.efer & EFER_SCE);
> > +
> > +       vmx_setup_uret_msr(vmx, MSR_STAR, load_syscall_msrs);
> > +       vmx_setup_uret_msr(vmx, MSR_LSTAR, load_syscall_msrs);
> > +       vmx_setup_uret_msr(vmx, MSR_SYSCALL_MASK, load_syscall_msrs);
> >  #endif
> > -       if (update_transition_efer(vmx))
> > -               vmx_setup_uret_msr(vmx, MSR_EFER);
> > +       vmx_setup_uret_msr(vmx, MSR_EFER, update_transition_efer(vmx));
> >
> > -       if (guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP)  ||
> > -           guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDPID))
> > -               vmx_setup_uret_msr(vmx, MSR_TSC_AUX);
> > +       vmx_setup_uret_msr(vmx, MSR_TSC_AUX,
> > +                          guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP) ||
> > +                          guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDPID));
> 
> Shouldn't vmx_setup_uret_msr(,MSR_TSC_AUX,) be called to update
> the new flag load_into_hardware for MSR_TSC_AUX when CPUID
> (X86_FEATURE_RDTSCP/X86_FEATURE_RDPID) of the vCPU is updated ?

Yes.  I have a patch in the massive vCPU RESET/INIT series to do exactly that.
I honestly can't remember if there was a dependency that "required" the fix to
be buried in the middle of that series.  I suspect not; I'm guessing I just
didn't think it was worth backporting to stable kernels and so didn't prioritize
hoisting the patch out of that mess.

https://lkml.kernel.org/r/20210424004645.3950558-34-seanjc@google.com

  reply	other threads:[~2021-05-10 16:44 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-04 17:17 [PATCH 00/15] KVM: x86: RDPID/RDTSCP fixes and uret MSR cleanups Sean Christopherson
2021-05-04 17:17 ` [PATCH 01/15] KVM: VMX: Do not adverise RDPID if ENABLE_RDTSCP control is unsupported Sean Christopherson
2021-05-04 17:37   ` Jim Mattson
2021-05-04 17:53     ` Jim Mattson
2021-05-04 18:14       ` Sean Christopherson
2021-05-05  3:04   ` Reiji Watanabe
2021-05-10  8:03   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 02/15] KVM: x86: Emulate RDPID only if RDTSCP is supported Sean Christopherson
2021-05-04 17:50   ` Jim Mattson
2021-05-05  3:51   ` Reiji Watanabe
2021-05-05  8:01     ` Paolo Bonzini
2021-05-10  8:08   ` Maxim Levitsky
2021-05-10 17:20     ` Sean Christopherson
2021-05-11 12:32       ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 03/15] KVM: SVM: Inject #UD on RDTSCP when it should be disabled in the guest Sean Christopherson
2021-05-04 21:45   ` Jim Mattson
2021-05-04 21:53     ` Sean Christopherson
2021-05-04 21:56       ` Jim Mattson
2021-05-04 22:10         ` Sean Christopherson
2021-05-04 22:24           ` Jim Mattson
2021-05-04 21:57       ` Paolo Bonzini
2021-05-04 21:58         ` Jim Mattson
2021-05-10  8:08           ` Maxim Levitsky
2021-05-10 16:56             ` Sean Christopherson
2021-05-11 12:34               ` Maxim Levitsky
2021-05-18 10:59               ` Paolo Bonzini
2021-05-18 19:24                 ` Sean Christopherson
2021-05-05  4:26   ` Reiji Watanabe
2021-05-10  8:08   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 04/15] KVM: x86: Move RDPID emulation intercept to its own enum Sean Christopherson
2021-05-04 23:24   ` Jim Mattson
2021-05-10  8:14   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 05/15] KVM: VMX: Disable preemption when probing user return MSRs Sean Christopherson
2021-05-04 23:36   ` Jim Mattson
2021-05-10  8:18   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 06/15] KVM: SVM: Probe and load MSR_TSC_AUX regardless of RDTSCP support in host Sean Christopherson
2021-05-10  8:20   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 07/15] KVM: x86: Add support for RDPID without RDTSCP Sean Christopherson
2021-05-10  8:20   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 08/15] KVM: VMX: Configure list of user return MSRs at module init Sean Christopherson
2021-05-10  8:23   ` Maxim Levitsky
2021-05-10 15:13     ` Sean Christopherson
2021-05-11 12:34       ` Maxim Levitsky
2021-05-11 20:10         ` Sean Christopherson
2021-05-04 17:17 ` [PATCH 09/15] KVM: VMX: Use flag to indicate "active" uret MSRs instead of sorting list Sean Christopherson
2021-05-08  3:31   ` Reiji Watanabe
2021-05-10 16:43     ` Sean Christopherson [this message]
2021-05-10 17:55       ` Reiji Watanabe
2021-05-10  8:25   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 10/15] KVM: VMX: Use common x86's uret MSR list as the one true list Sean Christopherson
2021-05-10  8:25   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 11/15] KVM: VMX: Disable loading of TSX_CTRL MSR the more conventional way Sean Christopherson
2021-05-05  8:49   ` Paolo Bonzini
2021-05-05 15:36     ` Sean Christopherson
2021-05-05 15:50       ` Paolo Bonzini
2021-05-10  8:26   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 12/15] KVM: x86: Export the number of uret MSRs to vendor modules Sean Christopherson
2021-05-10  8:27   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 13/15] KVM: x86: Move uret MSR slot management to common x86 Sean Christopherson
2021-05-10  8:28   ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 14/15] KVM: x86: Tie Intel and AMD behavior for MSR_TSC_AUX to guest CPU model Sean Christopherson
2021-05-10  8:29   ` Maxim Levitsky
2021-05-10 16:50     ` Sean Christopherson
2021-05-10 17:11       ` Jim Mattson
2021-05-11 12:34         ` Maxim Levitsky
2021-05-04 17:17 ` [PATCH 15/15] KVM: x86: Hide RDTSCP and RDPID if MSR_TSC_AUX probing failed Sean Christopherson
2021-05-10  8:29   ` Maxim Levitsky
2021-05-05  8:51 ` [PATCH 00/15] KVM: x86: RDPID/RDTSCP fixes and uret MSR cleanups Paolo Bonzini

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YJlixiTcwFkrnxIL@google.com \
    --to=seanjc@google.com \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=reijiw@google.com \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.com \
    --cc=xiaoyao.li@intel.com \
    --subject='Re: [PATCH 09/15] KVM: VMX: Use flag to indicate "active" uret MSRs instead of sorting list' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).