minios: permit blkfront to write from mapped memory

by adding a virtual_to_mfn macro

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

extras/mini-os/blkfront.c

@@ -88,7 +88,7 @@ struct blkfront_dev *init_blkfront(char *nodename, uint64_t *sectors, unsigned *
     SHARED_RING_INIT(s);
     FRONT_RING_INIT(&dev->ring, s, PAGE_SIZE);
 
-    dev->ring_ref = gnttab_grant_access(0,virt_to_mfn(s),0);
+    dev->ring_ref = gnttab_grant_access(0,virtual_to_mfn(s),0);
 
     evtchn_alloc_unbound_t op;
     op.dom = DOMID_SELF;

extras/mini-os/include/ia64/arch_mm.h

@@ -25,6 +25,7 @@
 #define __ARCH_MM_H__
 
 #include "page.h"
+#include "ia64_cpu.h"
 
 #define PFN_PHYS(x)	(pfn_to_page(x))
 #define PHYS_PFN(x)	(page_to_pfn(x))
@@ -32,6 +33,7 @@
 #define to_phys(x)	__pa(x)
 
 #define virt_to_mfn(x)	virt_to_pfn(x)
+#define virtual_to_mfn(x)      (ia64_tpa((uint64_t)(x)) >> PAGE_SHIFT)
 
 #define STACK_SIZE_PAGE_ORDER   1
 #define STACK_SIZE              (PAGE_SIZE * (1 << STACK_SIZE_PAGE_ORDER))

extras/mini-os/include/x86/arch_mm.h

@@ -226,6 +226,35 @@ static __inline__ paddr_t machine_to_phys(maddr_t machine)
 #define pte_to_mfn(_pte)           (((_pte) & (PADDR_MASK&PAGE_MASK)) >> L1_PAGETABLE_SHIFT)
 #define pte_to_virt(_pte)          to_virt(mfn_to_pfn(pte_to_mfn(_pte)) << PAGE_SHIFT)
 
+
+#define PT_BASE			   ((pgentry_t *)start_info.pt_base)
+
+#ifdef __x86_64__
+#define virtual_to_l3(_virt)	   ((pgentry_t *)pte_to_virt(PT_BASE[l4_table_offset(_virt)]))
+#else
+#define virtual_to_l3(_virt)	   PT_BASE
+#endif
+
+#if defined(__x86_64__) || defined(CONFIG_X86_PAE)
+#define virtual_to_l2(_virt)	   ({ \
+	unsigned long __virt2 = (_virt); \
+	(pgentry_t *) pte_to_virt(virtual_to_l3(__virt2)[l3_table_offset(__virt2)]); \
+})
+#else
+#define virtual_to_l2(_virt)	   PT_BASE
+#endif
+
+#define virtual_to_l1(_virt)	   ({ \
+	unsigned long __virt1 = (_virt); \
+	(pgentry_t *) pte_to_virt(virtual_to_l2(__virt1)[l2_table_offset(__virt1)]); \
+})
+
+#define virtual_to_pte(_virt)	   ({ \
+	unsigned long __virt0 = (unsigned long) (_virt); \
+	virtual_to_l1(__virt0)[l1_table_offset(__virt0)]; \
+})
+#define virtual_to_mfn(_virt)	   pte_to_mfn(virtual_to_pte(_virt))
+
 #define map_frames(f, n) map_frames_ex(f, n, 1, 0, 1, DOMID_SELF, 0, L1_PROT)
 #define map_zero(n, a) map_frames_ex(&mfn_zero, n, 0, 0, a, DOMID_SELF, 0, L1_PROT_RO)