Re: [Xen-devel] [PATCH linux 4/8] x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to the shared_info page

From: David Vrabel <david.vrabel@citrix.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>, <xen-devel@lists.xenproject.org>
Cc: Juergen Gross <jgross@suse.com>,
	Stefano Stabellini <sstabellini@kernel.org>, <x86@kernel.org>,
	<linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@redhat.com>,
	David Vrabel <david.vrabel@citrix.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [Xen-devel] [PATCH linux 4/8] x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to the shared_info page
Date: Wed, 29 Jun 2016 13:32:26 +0100	[thread overview]
Message-ID: <5773BFDA.1090706@citrix.com> (raw)
In-Reply-To: <1467132449-1030-5-git-send-email-vkuznets@redhat.com>

On 28/06/16 17:47, Vitaly Kuznetsov wrote:
> shared_info page has space for 32 vcpu info slots for first 32 vCPUs but
> these are the first 32 vCPUs from Xen's perspective and we should map them
> accordingly with the newly introduced xen_vcpu_id mapping.
> 
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  arch/x86/xen/enlighten.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 69f4c0c..1596626 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -189,6 +189,7 @@ static void xen_vcpu_setup(int cpu)
>  	struct vcpu_register_vcpu_info info;
>  	int err;
>  	struct vcpu_info *vcpup;
> +	int xen_cpu = per_cpu(xen_vcpu_id, cpu);

I think there should be a

static inline int xen_vcpu_nr(int cpu)
{
	return per_cpu(xen_vcpu_id, cpu);
}

helper function.

David