linux-kernel - Re: [PATCH v11 01/23] KVM: x86: Rename kvm_{g,s}et_msr()* to show that they emulate guest accesses

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: <5591ecc4-2383-4804-b3f0-0dcef692e8f6@zytor.com>
Date: Mon, 28 Jul 2025 15:31:41 -0700
From: Xin Li <xin@...or.com>
To: Chao Gao <chao.gao@...el.com>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, x86@...nel.org, seanjc@...gle.com,
        pbonzini@...hat.com, dave.hansen@...el.com
Cc: rick.p.edgecombe@...el.com, mlevitsk@...hat.com, john.allen@....com,
        weijiang.yang@...el.com, minipli@...ecurity.net,
        Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
        Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH v11 01/23] KVM: x86: Rename kvm_{g,s}et_msr()* to show
 that they emulate guest accesses

On 7/4/2025 1:49 AM, Chao Gao wrote:
> @@ -2764,7 +2764,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
>   
>   	if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL) &&
>   	    kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu)) &&
> -	    WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
> +	    WARN_ON_ONCE(kvm_emulate_msr_write(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
>   				     vmcs12->guest_ia32_perf_global_ctrl))) {

Not sure if the alignment should be adjusted based on the above modified
line.

>   		*entry_failure_code = ENTRY_FAIL_DEFAULT;
>   		return -EINVAL;
> @@ -4752,8 +4752,9 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
>   	}
>   	if ((vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL) &&
>   	    kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu)))
> -		WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
> -					 vmcs12->host_ia32_perf_global_ctrl));
> +		WARN_ON_ONCE(kvm_emulate_msr_write(vcpu,
> +					MSR_CORE_PERF_GLOBAL_CTRL,
> +					vmcs12->host_ia32_perf_global_ctrl));

Same here.

>   
>   	/* Set L1 segment info according to Intel SDM
>   	    27.5.2 Loading Host Segment and Descriptor-Table Registers */
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 7543dac7ae70..11d84075cd14 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1929,33 +1929,35 @@ static int kvm_get_msr_ignored_check(struct kvm_vcpu *vcpu,
>   				 __kvm_get_msr);
>   }
>   
> -int kvm_get_msr_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 *data)
> +int kvm_emulate_msr_read_with_filter(struct kvm_vcpu *vcpu, u32 index,
> +				     u64 *data)

I think the extra new line doesn't improve readability, but it's the
maintainer's call.

>   {
>   	if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_READ))
>   		return KVM_MSR_RET_FILTERED;
>   	return kvm_get_msr_ignored_check(vcpu, index, data, false);
>   }
> -EXPORT_SYMBOL_GPL(kvm_get_msr_with_filter);
> +EXPORT_SYMBOL_GPL(kvm_emulate_msr_read_with_filter);
>   
> -int kvm_set_msr_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 data)
> +int kvm_emulate_msr_write_with_filter(struct kvm_vcpu *vcpu, u32 index,

Ditto.

> +				      u64 data)
>   {
>   	if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_WRITE))
>   		return KVM_MSR_RET_FILTERED;