linux-kernel - Re: [PATCH 11/18] KVM: TDX: Add methods to ignore accesses to CPU state

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: <67dd44fb-0211-4435-a294-b9f00dc681d8@linux.intel.com>
Date: Wed, 15 Jan 2025 14:51:14 +0800
From: Binbin Wu <binbin.wu@...ux.intel.com>
To: pbonzini@...hat.com, seanjc@...gle.com, kvm@...r.kernel.org
Cc: rick.p.edgecombe@...el.com, kai.huang@...el.com, adrian.hunter@...el.com,
 reinette.chatre@...el.com, xiaoyao.li@...el.com,
 tony.lindgren@...ux.intel.com, isaku.yamahata@...el.com,
 yan.y.zhao@...el.com, chao.gao@...el.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 11/18] KVM: TDX: Add methods to ignore accesses to CPU
 state




On 12/10/2024 8:49 AM, Binbin Wu wrote:
[...]
>   
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index 413359741085..4bf3a6dc66fc 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -733,8 +733,15 @@ int tdx_vcpu_create(struct kvm_vcpu *vcpu)
>   
>   	vcpu->arch.tsc_offset = kvm_tdx->tsc_offset;
>   	vcpu->arch.l1_tsc_offset = vcpu->arch.tsc_offset;
> -	vcpu->arch.guest_state_protected =
> -		!(to_kvm_tdx(vcpu->kvm)->attributes & TDX_TD_ATTR_DEBUG);
> +	/*
> +	 * TODO: support off-TD debug.  If TD DEBUG is enabled, guest state
> +	 * can be accessed. guest_state_protected = false. and kvm ioctl to
> +	 * access CPU states should be usable for user space VMM (e.g. qemu).
> +	 *
> +	 * vcpu->arch.guest_state_protected =
> +	 *	!(to_kvm_tdx(vcpu->kvm)->attributes & TDX_TD_ATTR_DEBUG);
> +	 */
> +	vcpu->arch.guest_state_protected = true;
This was mistakenly introduced during re-base and should be discarded.


>   
>   	if ((kvm_tdx->xfam & XFEATURE_MASK_XTILE) == XFEATURE_MASK_XTILE)
>   		vcpu->arch.xfd_no_write_intercept = true;
> @@ -2134,6 +2141,23 @@ int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
>   	}
>   }
>   
[...]