From: Yang Weijiang <weijiang.yang@intel.com>
To: Jim Mattson <jmattson@google.com>
Cc: "Yang Weijiang" <weijiang.yang@intel.com>,
"kvm list" <kvm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Sean Christopherson" <sean.j.christopherson@intel.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Subject: Re: [PATCH v7 6/7] KVM: x86: Load Guest fpu state when accessing MSRs managed by XSAVES
Date: Wed, 9 Oct 2019 14:46:48 +0800 [thread overview]
Message-ID: <20191009064648.GD27851@local-michael-cet-test> (raw)
In-Reply-To: <CALMp9eRouyhkKeadM_w80bisWB-VSBCf3NSei5hZXcDsRR7GJg@mail.gmail.com>
On Wed, Oct 02, 2019 at 12:56:30PM -0700, Jim Mattson wrote:
> On Thu, Sep 26, 2019 at 7:17 PM Yang Weijiang <weijiang.yang@intel.com> wrote:
> >
> > From: Sean Christopherson <sean.j.christopherson@intel.com>
> >
> /*
> > * Read or write a bunch of msrs. All parameters are kernel addresses.
> > *
> > @@ -3009,11 +3017,23 @@ static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
> > int (*do_msr)(struct kvm_vcpu *vcpu,
> > unsigned index, u64 *data))
> > {
> > + bool fpu_loaded = false;
> > int i;
> > + const u64 cet_bits = XFEATURE_MASK_CET_USER | XFEATURE_MASK_CET_KERNEL;
> > + bool cet_xss = kvm_x86_ops->xsaves_supported() &&
> > + (kvm_supported_xss() & cet_bits);
>
> It seems like I've seen a lot of checks like this. Can this be
> simplified (throughout this series) by sinking the
> kvm_x86_ops->xsaves_supported() check into kvm_supported_xss()? That
> is, shouldn't kvm_supported_xss() return 0 if
> kvm_x86_ops->xsaves_supported() is false?
>
OK, let me add this check, thank you!
> > - for (i = 0; i < msrs->nmsrs; ++i)
> > + for (i = 0; i < msrs->nmsrs; ++i) {
> > + if (!fpu_loaded && cet_xss &&
> > + is_xsaves_msr(entries[i].index)) {
> > + kvm_load_guest_fpu(vcpu);
> > + fpu_loaded = true;
> > + }
> > if (do_msr(vcpu, entries[i].index, &entries[i].data))
> > break;
> > + }
> > + if (fpu_loaded)
> > + kvm_put_guest_fpu(vcpu);
> >
> > return i;
> > }
> > --
> > 2.17.2
> >
next prev parent reply other threads:[~2019-10-09 6:44 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-27 2:19 [PATCH v7 0/7] Introduce support for Guest CET feature Yang Weijiang
2019-09-27 2:19 ` [PATCH v7 1/7] KVM: CPUID: Fix IA32_XSS support in CPUID(0xd,i) enumeration Yang Weijiang
2019-10-02 17:26 ` Jim Mattson
2019-10-08 8:30 ` Yang Weijiang
2019-10-17 19:46 ` Sean Christopherson
2019-10-18 1:28 ` Yang Weijiang
2019-10-22 19:46 ` Sean Christopherson
2019-10-23 1:16 ` Yang Weijiang
2019-09-27 2:19 ` [PATCH v7 2/7] kvm: vmx: Define CET VMCS fields and CPUID flags Yang Weijiang
2019-10-02 18:04 ` Jim Mattson
2019-10-09 5:56 ` Yang Weijiang
2019-09-27 2:19 ` [PATCH v7 3/7] KVM: VMX: Pass through CET related MSRs to Guest Yang Weijiang
2019-10-02 18:18 ` Jim Mattson
2019-10-09 6:15 ` Yang Weijiang
2019-10-10 19:04 ` Jim Mattson
2019-10-11 1:51 ` Yang Weijiang
2019-10-17 20:04 ` Sean Christopherson
2019-10-18 1:31 ` Yang Weijiang
2019-09-27 2:19 ` [PATCH v7 4/7] KVM: VMX: Load Guest CET via VMCS when CET is enabled in Guest Yang Weijiang
2019-10-02 18:54 ` Jim Mattson
2019-10-09 6:43 ` Yang Weijiang
2019-10-09 23:08 ` Jim Mattson
2019-10-10 1:30 ` Yang Weijiang
2019-10-10 23:44 ` Jim Mattson
2019-10-11 1:43 ` Yang Weijiang
2019-09-27 2:19 ` [PATCH v7 5/7] kvm: x86: Add CET CR4 bit and XSS support Yang Weijiang
2019-10-02 19:05 ` Jim Mattson
2019-10-17 19:56 ` Sean Christopherson
2019-10-18 1:58 ` Yang Weijiang
2019-10-22 20:13 ` Sean Christopherson
2019-10-23 1:19 ` Yang Weijiang
2019-09-27 2:19 ` [PATCH v7 6/7] KVM: x86: Load Guest fpu state when accessing MSRs managed by XSAVES Yang Weijiang
2019-10-02 19:56 ` Jim Mattson
2019-10-09 6:46 ` Yang Weijiang [this message]
2019-09-27 2:19 ` [PATCH v7 7/7] KVM: x86: Add user-space access interface for CET MSRs Yang Weijiang
2019-10-02 20:57 ` Jim Mattson
2019-10-09 6:56 ` Yang Weijiang
2019-10-17 19:58 ` Sean Christopherson
2019-10-18 1:32 ` Yang Weijiang
2019-10-02 22:40 ` [PATCH v7 0/7] Introduce support for Guest CET feature Jim Mattson
2019-10-03 13:01 ` Yang Weijiang
2019-10-03 16:33 ` Jim Mattson
2019-10-08 8:50 ` Yang Weijiang
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