Re: [PATCH 15/27] nVMX: Prepare vmcs02 from vmcs01 and vmcs12

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On 02/08/2011 02:13 PM, Nadav Har'El wrote:
But while doing this, I came across a question that I wonder if you can
clarify for me:

Among the other things it sets up, vmx_vcpu_setup() sets

	rdmsrl(MSR_IA32_SYSENTER_ESP, a);
	vmcs_writel(HOST_IA32_SYSENTER_ESP, a);   /* 22.2.3 */

Why is this needed here?

It's not needed here.

In vmx_vcpu_load(), when a cpu is known (or changed),
we again have:

	rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
	vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */

So isn't the first setting, in vmx_vcpu_setup(), redundant?

It is. It's just historical baggage - these lines were introduced about 20 commits into kvm development (af9d6e204919016ca in qemu-kvm.git) and never removed, even after it was fixed to be per-cpu.

--
error compiling committee.c: too many arguments to function

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