提交 d451bb7a 编写于 作者: J Jeremy Fitzhardinge 提交者: Thomas Gleixner

xen: make phys_to_machine structure dynamic

We now support the use of memory hotplug, so the physical to machine
page mapping structure must be dynamic.  This is implemented as a
two-level radix tree structure, which allows us to efficiently
incrementally allocate memory for the p2m table as new pages are
added.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
上级 955d6f17
......@@ -1221,7 +1221,7 @@ asmlinkage void __init xen_start_kernel(void)
/* Get mfn list */
if (!xen_feature(XENFEAT_auto_translated_physmap))
phys_to_machine_mapping = (unsigned long *)xen_start_info->mfn_list;
xen_build_dynamic_phys_to_machine();
pgd = (pgd_t *)xen_start_info->pt_base;
......
......@@ -56,6 +56,91 @@
#include "multicalls.h"
#include "mmu.h"
/*
* This should probably be a config option. On 32-bit, it costs 1
* page/gig of memory; on 64-bit its 2 pages/gig. If we want it to be
* completely unbounded we can add another level to the p2m structure.
*/
#define MAX_GUEST_PAGES (16ull * 1024*1024*1024 / PAGE_SIZE)
#define P2M_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
static unsigned long *p2m_top[MAX_GUEST_PAGES / P2M_ENTRIES_PER_PAGE];
static inline unsigned p2m_top_index(unsigned long pfn)
{
BUG_ON(pfn >= MAX_GUEST_PAGES);
return pfn / P2M_ENTRIES_PER_PAGE;
}
static inline unsigned p2m_index(unsigned long pfn)
{
return pfn % P2M_ENTRIES_PER_PAGE;
}
void __init xen_build_dynamic_phys_to_machine(void)
{
unsigned pfn;
unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
BUG_ON(xen_start_info->nr_pages >= MAX_GUEST_PAGES);
for(pfn = 0;
pfn < xen_start_info->nr_pages;
pfn += P2M_ENTRIES_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
p2m_top[topidx] = &mfn_list[pfn];
}
}
unsigned long get_phys_to_machine(unsigned long pfn)
{
unsigned topidx, idx;
topidx = p2m_top_index(pfn);
if (p2m_top[topidx] == NULL)
return INVALID_P2M_ENTRY;
idx = p2m_index(pfn);
return p2m_top[topidx][idx];
}
static void alloc_p2m(unsigned long **pp)
{
unsigned long *p;
unsigned i;
p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL);
BUG_ON(p == NULL);
for(i = 0; i < P2M_ENTRIES_PER_PAGE; i++)
p[i] = INVALID_P2M_ENTRY;
if (cmpxchg(pp, NULL, p) != NULL)
free_page((unsigned long)p);
}
void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
{
unsigned topidx, idx;
if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
return;
}
topidx = p2m_top_index(pfn);
if (p2m_top[topidx] == NULL) {
/* no need to allocate a page to store an invalid entry */
if (mfn == INVALID_P2M_ENTRY)
return;
alloc_p2m(&p2m_top[topidx]);
}
idx = p2m_index(pfn);
p2m_top[topidx][idx] = mfn;
}
xmaddr_t arbitrary_virt_to_machine(unsigned long address)
{
unsigned int level;
......
......@@ -27,8 +27,6 @@
extern const char xen_hypervisor_callback[];
extern const char xen_failsafe_callback[];
unsigned long *phys_to_machine_mapping;
EXPORT_SYMBOL(phys_to_machine_mapping);
/**
* machine_specific_memory_setup - Hook for machine specific memory setup.
......
......@@ -22,6 +22,8 @@ void __init xen_arch_setup(void);
void __init xen_init_IRQ(void);
void xen_enable_sysenter(void);
void __init xen_build_dynamic_phys_to_machine(void);
void xen_setup_timer(int cpu);
void xen_setup_cpu_clockevents(void);
unsigned long xen_cpu_khz(void);
......
......@@ -26,15 +26,15 @@ typedef struct xpaddr {
#define FOREIGN_FRAME_BIT (1UL<<31)
#define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT)
extern unsigned long *phys_to_machine_mapping;
extern unsigned long get_phys_to_machine(unsigned long pfn);
extern void set_phys_to_machine(unsigned long pfn, unsigned long mfn);
static inline unsigned long pfn_to_mfn(unsigned long pfn)
{
if (xen_feature(XENFEAT_auto_translated_physmap))
return pfn;
return phys_to_machine_mapping[(unsigned int)(pfn)] &
~FOREIGN_FRAME_BIT;
return get_phys_to_machine(pfn) & ~FOREIGN_FRAME_BIT;
}
static inline int phys_to_machine_mapping_valid(unsigned long pfn)
......@@ -42,7 +42,7 @@ static inline int phys_to_machine_mapping_valid(unsigned long pfn)
if (xen_feature(XENFEAT_auto_translated_physmap))
return 1;
return (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY);
return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
}
static inline unsigned long mfn_to_pfn(unsigned long mfn)
......@@ -106,20 +106,12 @@ static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
unsigned long pfn = mfn_to_pfn(mfn);
if ((pfn < max_mapnr)
&& !xen_feature(XENFEAT_auto_translated_physmap)
&& (phys_to_machine_mapping[pfn] != mfn))
&& (get_phys_to_machine(pfn) != mfn))
return max_mapnr; /* force !pfn_valid() */
/* XXX fixme; not true with sparsemem */
return pfn;
}
static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
{
if (xen_feature(XENFEAT_auto_translated_physmap)) {
BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
return;
}
phys_to_machine_mapping[pfn] = mfn;
}
/* VIRT <-> MACHINE conversion */
#define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
#define virt_to_mfn(v) (pfn_to_mfn(PFN_DOWN(__pa(v))))
......
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