linux-kernel - Re: [PATCH 10/25] KVM: TDX: Initialize KVM supported capabilities when module setup

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: <ZtGGYmE3rE7d1wiu@tlindgre-MOBL1>
Date: Fri, 30 Aug 2024 11:44:18 +0300
From: Tony Lindgren <tony.lindgren@...ux.intel.com>
To: "Huang, Kai" <kai.huang@...el.com>
Cc: "Gao, Chao" <chao.gao@...el.com>,
	"Edgecombe, Rick P" <rick.p.edgecombe@...el.com>,
	"Li, Xiaoyao" <xiaoyao.li@...el.com>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"pbonzini@...hat.com" <pbonzini@...hat.com>,
	"seanjc@...gle.com" <seanjc@...gle.com>,
	"isaku.yamahata@...il.com" <isaku.yamahata@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 10/25] KVM: TDX: Initialize KVM supported capabilities
 when module setup

On Tue, Aug 13, 2024 at 05:26:06AM +0000, Huang, Kai wrote:
> On Tue, 2024-08-13 at 11:25 +0800, Chao Gao wrote:
> > > +	for (i = 0; i < td_conf->num_cpuid_config; i++) {
> > > +		struct kvm_tdx_cpuid_config source = {
> > > +			.leaf = (u32)td_conf->cpuid_config_leaves[i],
> > > +			.sub_leaf = td_conf->cpuid_config_leaves[i] >> 32,
> > > +			.eax = (u32)td_conf->cpuid_config_values[i].eax_ebx,
> > > +			.ebx = td_conf->cpuid_config_values[i].eax_ebx >> 32,
> > > +			.ecx = (u32)td_conf->cpuid_config_values[i].ecx_edx,
> > > +			.edx = td_conf->cpuid_config_values[i].ecx_edx >> 32,
> > > +		};
> > > +		struct kvm_tdx_cpuid_config *dest =
> > > +			&kvm_tdx_caps->cpuid_configs[i];
> > > +
> > > +		memcpy(dest, &source, sizeof(struct kvm_tdx_cpuid_config));
> > 
> > this memcpy() looks superfluous. does this work?
> > 
> > 		kvm_tdx_caps->cpuid_configs[i] = {
> > 			.leaf = (u32)td_conf->cpuid_config_leaves[i],
> > 			.sub_leaf = td_conf->cpuid_config_leaves[i] >> 32,
> > 			.eax = (u32)td_conf->cpuid_config_values[i].eax_ebx,
> > 			.ebx = td_conf->cpuid_config_values[i].eax_ebx >> 32,
> > 			.ecx = (u32)td_conf->cpuid_config_values[i].ecx_edx,
> > 			.edx = td_conf->cpuid_config_values[i].ecx_edx >> 32,
> > 		};
> 
> This looks good to me.  I didn't try to optimize because it's done in the
> module loading time.

I'll do a patch to initialize dest directly without a memcpy().

Tony