From: Yang Weijiang <weijiang.yang@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Yang Weijiang <weijiang.yang@intel.com>,
seanjc@google.com, jmattson@google.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, yu.c.zhang@linux.intel.com
Subject: Re: [PATCH v15 07/14] KVM: VMX: Emulate reads and writes to CET MSRs
Date: Wed, 3 Feb 2021 20:50:16 +0800 [thread overview]
Message-ID: <20210203125016.GA6080@local-michael-cet-test> (raw)
In-Reply-To: <6a743d57-8128-b5db-ddc1-9dd4c4c1004e@redhat.com>
On Wed, Feb 03, 2021 at 12:57:41PM +0100, Paolo Bonzini wrote:
> On 03/02/21 12:34, Yang Weijiang wrote:
> > MSRs that are switched through XSAVES are especially annoying due to the
> > possibility of the kernel's FPU being used in IRQ context. Disable IRQs
> > and ensure the guest's FPU state is loaded when accessing such MSRs.
>
> Good catch! This should be in x86.h and named kvm_get/set_xsave_msr because
> it's not VMX specific. The commit message should also be there as a
> comment.
Thanks a lot for reviewing! These words came from Sean! :-D
>
> In addition,
>
> > + case MSR_IA32_S_CET:
> > + if (!cet_is_control_msr_accessible(vcpu, msr_info))
> > + return 1;
> > + msr_info->data = vmcs_readl(GUEST_S_CET);
> > + break;
> > + case MSR_IA32_U_CET:
> > + if (!cet_is_control_msr_accessible(vcpu, msr_info))
> > + return 1;
> > + vmx_get_xsave_msr(msr_info);
> > + break;
>
> these two might as well be the same "case" for symmetry with the handling of
> WRMSR.
>
> I've fixed this up locally, since these patches will not be pushed to Linus
> until the corresponding bare metal support is there.
Got it!
>
> Paolo
next prev parent reply other threads:[~2021-02-03 12:39 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-03 11:34 [PATCH v15 00/14] Introduce support for guest CET feature Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 01/14] KVM: x86: Report XSS as an MSR to be saved if there are supported features Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 02/14] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 03/14] KVM: x86: Load guest fpu state when accessing MSRs managed by XSAVES Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 04/14] KVM: x86: Add #CP support in guest exception dispatch Yang Weijiang
2021-02-03 21:46 ` Sean Christopherson
2021-02-04 7:22 ` Yang Weijiang
2021-02-04 8:28 ` Paolo Bonzini
2021-02-04 8:24 ` Paolo Bonzini
2021-02-04 16:42 ` Sean Christopherson
2021-02-04 17:29 ` Paolo Bonzini
2021-02-03 11:34 ` [PATCH v15 05/14] KVM: VMX: Introduce CET VMCS fields and flags Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 06/14] KVM: x86: Add fault checks for CR4.CET Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 07/14] KVM: VMX: Emulate reads and writes to CET MSRs Yang Weijiang
2021-02-03 11:57 ` Paolo Bonzini
2021-02-03 12:50 ` Yang Weijiang [this message]
2022-05-18 15:55 ` John Allen
2022-05-18 16:16 ` Sean Christopherson
2022-05-19 8:49 ` Yang, Weijiang
2021-02-03 11:34 ` [PATCH v15 08/14] KVM: VMX: Add a synthetic MSR to allow userspace VMM to access GUEST_SSP Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 09/14] KVM: x86: Report CET MSRs as to-be-saved if CET is supported Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 10/14] KVM: x86: Enable CET virtualization for VMX and advertise CET to userspace Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 11/14] KVM: VMX: Pass through CET MSRs to the guest when supported Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 12/14] KVM: nVMX: Add helper to check the vmcs01 MSR bitmap for MSR pass-through Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 13/14] KVM: nVMX: Enable CET support for nested VMX Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 14/14] KVM: x86: Save/Restore GUEST_SSP to/from SMRAM Yang Weijiang
2021-02-03 12:07 ` Paolo Bonzini
2021-02-03 12:59 ` Yang Weijiang
2021-02-03 12:40 ` [PATCH v15 00/14] Introduce support for guest CET feature Paolo Bonzini
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