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Subject: Re: [PATCH v2 1/2] KVM: nVMX: enhance allocate/free_vpid to handle
 shadow vpid
To: Wanpeng Li <wanpeng.li@hotmail.com>
References: <1442313034-14243-1-git-send-email-wanpeng.li@hotmail.com>
 <BLU436-SMTP2539135088523E893EC341A805C0@phx.gbl>
Cc: Jan Kiszka <jan.kiszka@siemens.com>, Bandan Das <bsd@redhat.com>,
        Wincy Van <fanwenyi0529@gmail.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <55F81515.8090405@redhat.com>
Date: Tue, 15 Sep 2015 14:54:45 +0200
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On 15/09/2015 12:30, Wanpeng Li wrote:
> +	if (!nested) {
> +		vpid = find_first_zero_bit(vmx_vpid_bitmap, VMX_NR_VPIDS);
> +		if (vpid < VMX_NR_VPIDS) {
>  		vmx->vpid = vpid;
>  		__set_bit(vpid, vmx_vpid_bitmap);
> +		}
> +	} else {
> +		vpid = find_first_zero_bit(vmx_vpid_bitmap, VMX_NR_VPIDS);
> +		if (vpid < VMX_NR_VPIDS) {
> +			vmx->nested.vpid02 = vpid;
> +			__set_bit(vpid, vmx_vpid_bitmap);
> +		}

Messy indentation, and a lot of duplicate code.  Can you instead have
(which I think was Jan's suggestion too):

static int allocate_vpid(void);
static void free_vpid(int vpid);

That said, I like the simple solution to the "too many VPIDs for each L1
VCPU" processor.

Paolo