[RFC 23/23] arm/xen: Add support for 64KB page granularity

Hi,

On 23/06/15 15:19, Stefano Stabellini wrote:

quoted

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 224081c..dcfe251 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c

@@ -93,8 +93,8 @@ static void xen_percpu_init(void)
 	pr_info("Xen: initializing cpu%d\n", cpu);
 	vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 
-	info.mfn = __pa(vcpup) >> PAGE_SHIFT;
-	info.offset = offset_in_page(vcpup);
+	info.mfn = __pa(vcpup) >> XEN_PAGE_SHIFT;
+	info.offset = xen_offset_in_page(vcpup);
 
 	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
 	BUG_ON(err);

@@ -204,7 +204,7 @@ static int __init xen_guest_init(void)
 	xatp.domid = DOMID_SELF;
 	xatp.idx = 0;
 	xatp.space = XENMAPSPACE_shared_info;
-	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
+	xatp.gpfn = __pa(shared_info_page) >> XEN_PAGE_SHIFT;
 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 		BUG();

What about xen_remap_domain_mfn_range? I guess we don't support that use
case on 64K guests? If so, I would appreaciate an assert and/or an error
message.

The implementation of xen_remap_domain_mfn_range return -ENOSYS no
matter the page granularity.

This function is PV specific and has been added few months ago just for
a stub. See comment in the code:
"/* Not used by XENFEAT_auto_translated guests */"

Any logging/BUG_ON within this function is out of scope for this series.
And I don't think this will be really useful. Feel free to send a patch
for it.

Regards,

-- 
Julien Grall