Re: [PATCH RFC 01/13] xen: use the hardware e820 map on Dom0

2014-01-21 Thread John Baldwin 
On Tuesday, December 24, 2013 6:20:50 am Roger Pau Monne wrote:
 We need to do some tweaking of the hardware e820 map, since the memory
 layout provided by Xen and the e820 map doesn't match.
 
 This consists in clamping the e820 map so that regions above max_pfn
 are marked as unusuable.
 ---
  sys/x86/xen/pv.c |   35 +--
  1 files changed, 33 insertions(+), 2 deletions(-)
 
 diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
 index 4f7415e..ab4afba 100644
 --- a/sys/x86/xen/pv.c
 +++ b/sys/x86/xen/pv.c
 @@ -297,17 +297,48 @@ static void
  xen_pv_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, int *physmap_idx)
  {
   struct xen_memory_map memmap;
 + unsigned long max_pfn = HYPERVISOR_start_info-nr_pages;
 + u_int64_t mem_end = ptoa(max_pfn);
   u_int32_t size;
 - int rc;
 + int rc, mem_op, i;

One minor nit is that it is preferred to not initalize variables in 
declarations style-wise.  Aside from that, this looks fine to me.

   /* Fetch the E820 map from Xen */
   memmap.nr_entries = MAX_E820_ENTRIES;
   set_xen_guest_handle(memmap.buffer, xen_smap);
 - rc = HYPERVISOR_memory_op(XENMEM_memory_map, memmap);
 + mem_op = xen_initial_domain() ?
 + XENMEM_machine_memory_map :
 + XENMEM_memory_map;
 + rc = HYPERVISOR_memory_op(mem_op, memmap);
   if (rc)
   panic(unable to fetch Xen E820 memory map);
   size = memmap.nr_entries * sizeof(xen_smap[0]);
  
 + /*
 +  * This should be improved, Xen provides us with a single
 +  * chunk of physical memory that goes from 0 to max_pfn,
 +  * and what we do here is clamp the HW memory map to make
 +  * sure regions above max_pfn are marked as reserved.
 +  *
 +  * TRTTD would be to move the memory not used because of
 +  * the holes in the HW memory map to the now clamped regions
 +  * using XENMEM_{decrease/increase}_reservation.
 +  */
 + for (i = 0; i  memmap.nr_entries; i++) {
 + u_int64_t end = xen_smap[i].base + xen_smap[i].length;
 + if (xen_smap[i].type == SMAP_TYPE_MEMORY) {
 + if (xen_smap[i].base  mem_end) {
 + /* Mark as reserved */
 + xen_smap[i].type = SMAP_TYPE_RESERVED;
 + continue;
 + }
 + if (end  mem_end) {
 + /* Truncate region */
 + xen_smap[i].length -= end - mem_end;
 + }
 + }
 + }
 +
 +
   bios_add_smap_entries(xen_smap, size, physmap, physmap_idx);
  }
  
 -- 
 1.7.7.5 (Apple Git-26)
 
 

-- 
John Baldwin
___
freebsd-xen@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-xen
To unsubscribe, send any mail to freebsd-xen-unsubscr...@freebsd.org

[PATCH RFC 01/13] xen: use the hardware e820 map on Dom0

2013-12-24 Thread Roger Pau Monne 
We need to do some tweaking of the hardware e820 map, since the memory
layout provided by Xen and the e820 map doesn't match.

This consists in clamping the e820 map so that regions above max_pfn
are marked as unusuable.
---
 sys/x86/xen/pv.c |   35 +--
 1 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
index 4f7415e..ab4afba 100644
--- a/sys/x86/xen/pv.c
+++ b/sys/x86/xen/pv.c
@@ -297,17 +297,48 @@ static void
 xen_pv_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, int *physmap_idx)
 {
struct xen_memory_map memmap;
+   unsigned long max_pfn = HYPERVISOR_start_info-nr_pages;
+   u_int64_t mem_end = ptoa(max_pfn);
u_int32_t size;
-   int rc;
+   int rc, mem_op, i;
 
/* Fetch the E820 map from Xen */
memmap.nr_entries = MAX_E820_ENTRIES;
set_xen_guest_handle(memmap.buffer, xen_smap);
-   rc = HYPERVISOR_memory_op(XENMEM_memory_map, memmap);
+   mem_op = xen_initial_domain() ?
+   XENMEM_machine_memory_map :
+   XENMEM_memory_map;
+   rc = HYPERVISOR_memory_op(mem_op, memmap);
if (rc)
panic(unable to fetch Xen E820 memory map);
size = memmap.nr_entries * sizeof(xen_smap[0]);
 
+   /*
+* This should be improved, Xen provides us with a single
+* chunk of physical memory that goes from 0 to max_pfn,
+* and what we do here is clamp the HW memory map to make
+* sure regions above max_pfn are marked as reserved.
+*
+* TRTTD would be to move the memory not used because of
+* the holes in the HW memory map to the now clamped regions
+* using XENMEM_{decrease/increase}_reservation.
+*/
+   for (i = 0; i  memmap.nr_entries; i++) {
+   u_int64_t end = xen_smap[i].base + xen_smap[i].length;
+   if (xen_smap[i].type == SMAP_TYPE_MEMORY) {
+   if (xen_smap[i].base  mem_end) {
+   /* Mark as reserved */
+   xen_smap[i].type = SMAP_TYPE_RESERVED;
+   continue;
+   }
+   if (end  mem_end) {
+   /* Truncate region */
+   xen_smap[i].length -= end - mem_end;
+   }
+   }
+   }
+
+
bios_add_smap_entries(xen_smap, size, physmap, physmap_idx);
 }
 
-- 
1.7.7.5 (Apple Git-26)

___
freebsd-xen@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-xen
To unsubscribe, send any mail to freebsd-xen-unsubscr...@freebsd.org