Re: [RFC PATCH 4/8]: identity map, events, and xenbus related changes

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Aug 15, 2012 at 06:03:56PM -0700, Mukesh Rathor wrote:
> 
> ---
>  arch/x86/xen/setup.c               |   32 +++++++++++++++++++++++++++-----
>  drivers/xen/events.c               |    7 +++++++
>  drivers/xen/xenbus/xenbus_client.c |    2 +-
>  drivers/xen/xenbus/xenbus_probe.c  |    5 ++++-
>  4 files changed, 39 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
> index 936f21d..1c961fc 100644
> --- a/arch/x86/xen/setup.c
> +++ b/arch/x86/xen/setup.c
> @@ -26,6 +26,7 @@
>  #include <xen/interface/memory.h>
>  #include <xen/interface/physdev.h>
>  #include <xen/features.h>
> +#include "mmu.h"
>  #include "xen-ops.h"
>  #include "vdso.h"
>  
> @@ -222,6 +223,20 @@ static void __init xen_set_identity_and_release_chunk(
>  	*identity += set_phys_range_identity(start_pfn, end_pfn);
>  }
>  
> +/* For PVH, the pfns [0..MAX] are mapped to mfn's in the EPT/NPT. The mfns
> + * are released as part of this 1:1 mapping hypercall. We can't balloon down
> + * any time later because when p2m/EPT is updated, the mfns are already lost.
> + * Also, we map the entire IO space, ie, beyond max_pfn_mapped.

> + */
> +static void noinline __init xen_pvh_identity_map_chunk(unsigned long start_pfn,
> +						       unsigned long end_pfn)
> +{
> +	unsigned long pfn;
> +
> +	for (pfn = start_pfn; pfn < end_pfn; pfn++)
> +		xen_set_clr_mmio_pvh_pte(pfn, pfn, 1, 1);

Include a comment for what the '1' and '1' are for? Like:
		xen_set..(pfn, pfn, 1 /* Enable clearing */, 1 /* Do something .. */

> +}
> +
>  static unsigned long __init xen_set_identity_and_release(
>  	const struct e820entry *list, size_t map_size, unsigned long nr_pages)
>  {
> @@ -251,11 +266,18 @@ static unsigned long __init xen_set_identity_and_release(
>  			if (entry->type == E820_RAM)
>  				end_pfn = PFN_UP(entry->addr);
>  
> -			if (start_pfn < end_pfn)
> -				xen_set_identity_and_release_chunk(
> -					start_pfn, end_pfn, nr_pages,
> -					&released, &identity);
> -
> +			if (start_pfn < end_pfn) {
> +				if (xen_pvh_domain()) {
> +					xen_pvh_identity_map_chunk(start_pfn,
> +								   end_pfn);
> +					released += end_pfn - start_pfn;
> +					identity += end_pfn - start_pfn;
> +				} else {
> +					xen_set_identity_and_release_chunk(
> +						start_pfn, end_pfn, nr_pages,
> +						&released, &identity);
> +				}
> +			}
>  			start = end;
>  		}
>  	}
> diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> index 7595581..260113e 100644
> --- a/drivers/xen/events.c
> +++ b/drivers/xen/events.c
> @@ -1814,6 +1814,13 @@ void __init xen_init_IRQ(void)
>  		if (xen_initial_domain())
>  			pci_xen_initial_domain();
>  
> +		if (xen_pvh_domain()) {
> +			xen_callback_vector();
> +			return;
> +		}
> +
> +		/* PVH: TBD/FIXME: debug and fix eio map to work with pvh */
> +
>  		pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
>  		eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map);
>  		rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
> diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
> index b3e146e..c0fcff1 100644
> --- a/drivers/xen/xenbus/xenbus_client.c
> +++ b/drivers/xen/xenbus/xenbus_client.c
> @@ -743,7 +743,7 @@ static const struct xenbus_ring_ops ring_ops_hvm = {
>  
>  void __init xenbus_ring_ops_init(void)
>  {
> -	if (xen_pv_domain())
> +	if (xen_pv_domain() && !xen_pvh_domain())
>  		ring_ops = &ring_ops_pv;
>  	else
>  		ring_ops = &ring_ops_hvm;
> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> index b793723..735dd5c 100644
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -749,7 +749,10 @@ static int __init xenbus_init(void)
>  			if (err)
>  				goto out_error;
>  		}
> -		xen_store_interface = mfn_to_virt(xen_store_mfn);
> +		if (xen_pvh_domain())
> +			xen_store_interface = __va(xen_store_mfn<<PAGE_SHIFT);
> +		else
> +			xen_store_interface = mfn_to_virt(xen_store_mfn);
>  	}
>  
>  	/* Initialize the interface to xenstore. */
> -- 
> 1.7.2.3