From mboxrd@z Thu Jan  1 00:00:00 1970
From: Suravee Suthikulanit <suravee.suthikulpanit@amd.com>
Subject: Xen on Seattle
Date: Tue, 2 Sep 2014 01:01:08 -0500
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To: Ian Campbell <Ian.Campbell@citrix.com>, Stefano Stabellini <stefano.stabellini@citrix.com>, Julien Grall <julien.grall@linaro.org>
Cc: Joel Schopp <joel.schopp@amd.com>, xen-devel <xen-devel@lists.xen.org>, "Hurwitz, Sherry" <sherry.hurwitz@amd.com>
List-Id: xen-devel@lists.xenproject.org

Hi all,

I am running into an issue booting Xen on Seattle platform where dom0 
kernel failed to make the following hypercall in 
arch/arm/xen/enlighten.c: xen_percpu_init().

  HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info)

After investigation, the hypercall failed in the xen/common/domain.c: 
map_vcpu_info(), where it check

     if ( offset > (PAGE_SIZE - sizeof(vcpu_info_t)) )
         return -EINVAL;

Here:

(XEN) DEBUG0: map_vcpu_info: offset = 0x6790
(XEN) DEBUG0: map_vcpu_info: PAGE_SIZE = 0x1000
(XEN) DEBUG0: map_vcpu_info: sizeof(vcpu_info_t) = 0x30

If I understand correctly, it seems that the hypervisor is making 
assumption that the Dom0 guest is using 4K page size.  The PAGE_SHIFT in 
include/asm-arm/config.h is currently set to 12.  So, I have tried 
changing this to 16 (for 64K page). However, there is a restriction on 
the 16-bit value of the struct active_grant_entry { length:16; }. So, I 
cannot boot dom0 with 64K page size. Is this accurate?

Thanks,

Suravee