linux-kernel - Re: [PATCH v3 16/25] KVM: VMX: Move CPU_BASED_CR8_{LOAD,STORE}_EXITING filtering out of setup_vmcs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b648160c9bbf81f820b0c0bc8512c4e28fb1fc33.camel@redhat.com>
Date:   Tue, 12 Jul 2022 14:56:58 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     Vitaly Kuznetsov <vkuznets@...hat.com>, kvm@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>
Cc:     Anirudh Rayabharam <anrayabh@...ux.microsoft.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 16/25] KVM: VMX: Move
 CPU_BASED_CR8_{LOAD,STORE}_EXITING filtering out of setup_vmcs_config()

On Fri, 2022-07-08 at 16:42 +0200, Vitaly Kuznetsov wrote:
> As a preparation to reusing the result of setup_vmcs_config() in
> nested VMX MSR setup, move CPU_BASED_CR8_{LOAD,STORE}_EXITING filtering
> to vmx_exec_control().
> 
> No functional change intended.
> 
> Reviewed-by: Jim Mattson <jmattson@...gle.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
> ---
>  arch/x86/kvm/vmx/vmx.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 93ca9ff8e641..d7170990f469 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -2479,11 +2479,6 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
>                                 MSR_IA32_VMX_PROCBASED_CTLS,
>                                 &_cpu_based_exec_control) < 0)
>                 return -EIO;
> -#ifdef CONFIG_X86_64
> -       if (_cpu_based_exec_control & CPU_BASED_TPR_SHADOW)
> -               _cpu_based_exec_control &= ~CPU_BASED_CR8_LOAD_EXITING &
> -                                          ~CPU_BASED_CR8_STORE_EXITING;
> -#endif
>         if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) {
>                 if (adjust_vmx_controls(KVM_REQ_VMX_SECONDARY_VM_EXEC_CONTROL,
>                                         KVM_OPT_VMX_SECONDARY_VM_EXEC_CONTROL,
> @@ -4248,13 +4243,17 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx)
>         if (vmx->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)
>                 exec_control &= ~CPU_BASED_MOV_DR_EXITING;
>  
> -       if (!cpu_need_tpr_shadow(&vmx->vcpu)) {
> +       if (!cpu_need_tpr_shadow(&vmx->vcpu))
>                 exec_control &= ~CPU_BASED_TPR_SHADOW;
> +
>  #ifdef CONFIG_X86_64
> +       if (exec_control & CPU_BASED_TPR_SHADOW)
> +               exec_control &= ~(CPU_BASED_CR8_LOAD_EXITING |
> +                                 CPU_BASED_CR8_STORE_EXITING);
> +       else
>                 exec_control |= CPU_BASED_CR8_STORE_EXITING |
>                                 CPU_BASED_CR8_LOAD_EXITING;
>  #endif
> -       }
>         if (!enable_ept)
>                 exec_control |= CPU_BASED_CR3_STORE_EXITING |
>                                 CPU_BASED_CR3_LOAD_EXITING  |

Reviewed-by: Maxim Levitsky <mlevitsk@...hat.com>

Best regards,
	Maxim Levitsky