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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] x86/32: Re-factor mapcache data structure into per-domain and per-vcpu
# HG changeset patch
# User Keir Fraser <keir@xxxxxxxxxxxxx>
# Date 1191338938 -3600
# Node ID e1b574bc36b5068baf0053da32f8ca11a907625a
# Parent 818cc26e3926614d0e9c2431c746a56bb645337d
x86/32: Re-factor mapcache data structure into per-domain and per-vcpu
components. Greatly reduces size of 'struct domain'.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
xen/arch/x86/domain.c | 4 +
xen/arch/x86/x86_32/domain_page.c | 107 +++++++++++++++++++-------------------
xen/include/asm-x86/domain.h | 36 +++++++-----
3 files changed, 79 insertions(+), 68 deletions(-)
diff -r 818cc26e3926 -r e1b574bc36b5 xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c Tue Oct 02 13:19:25 2007 +0100
+++ b/xen/arch/x86/domain.c Tue Oct 02 16:28:58 2007 +0100
@@ -382,6 +382,8 @@ int vcpu_initialise(struct vcpu *v)
v->arch.flags = TF_kernel_mode;
+ mapcache_vcpu_init(v);
+
pae_l3_cache_init(&v->arch.pae_l3_cache);
paging_vcpu_init(v);
@@ -461,7 +463,7 @@ int arch_domain_create(struct domain *d)
#if defined(__i386__)
- mapcache_init(d);
+ mapcache_domain_init(d);
#else /* __x86_64__ */
diff -r 818cc26e3926 -r e1b574bc36b5 xen/arch/x86/x86_32/domain_page.c
--- a/xen/arch/x86/x86_32/domain_page.c Tue Oct 02 13:19:25 2007 +0100
+++ b/xen/arch/x86/x86_32/domain_page.c Tue Oct 02 16:28:58 2007 +0100
@@ -43,9 +43,10 @@ void *map_domain_page(unsigned long mfn)
void *map_domain_page(unsigned long mfn)
{
unsigned long va;
- unsigned int idx, i, vcpu;
- struct vcpu *v;
- struct mapcache *cache;
+ unsigned int idx, i;
+ struct vcpu *v;
+ struct mapcache_domain *dcache;
+ struct mapcache_vcpu *vcache;
struct vcpu_maphash_entry *hashent;
ASSERT(!in_irq());
@@ -54,59 +55,59 @@ void *map_domain_page(unsigned long mfn)
v = mapcache_current_vcpu();
- vcpu = v->vcpu_id;
- cache = &v->domain->arch.mapcache;
-
- hashent = &cache->vcpu_maphash[vcpu].hash[MAPHASH_HASHFN(mfn)];
+ dcache = &v->domain->arch.mapcache;
+ vcache = &v->arch.mapcache;
+
+ hashent = &vcache->hash[MAPHASH_HASHFN(mfn)];
if ( hashent->mfn == mfn )
{
idx = hashent->idx;
hashent->refcnt++;
ASSERT(idx < MAPCACHE_ENTRIES);
ASSERT(hashent->refcnt != 0);
- ASSERT(l1e_get_pfn(cache->l1tab[idx]) == mfn);
+ ASSERT(l1e_get_pfn(dcache->l1tab[idx]) == mfn);
goto out;
}
- spin_lock(&cache->lock);
+ spin_lock(&dcache->lock);
/* Has some other CPU caused a wrap? We must flush if so. */
- if ( unlikely(cache->epoch != cache->shadow_epoch[vcpu]) )
- {
- cache->shadow_epoch[vcpu] = cache->epoch;
- if ( NEED_FLUSH(this_cpu(tlbflush_time), cache->tlbflush_timestamp) )
+ if ( unlikely(dcache->epoch != vcache->shadow_epoch) )
+ {
+ vcache->shadow_epoch = dcache->epoch;
+ if ( NEED_FLUSH(this_cpu(tlbflush_time), dcache->tlbflush_timestamp) )
{
perfc_incr(domain_page_tlb_flush);
local_flush_tlb();
}
}
- idx = find_next_zero_bit(cache->inuse, MAPCACHE_ENTRIES, cache->cursor);
+ idx = find_next_zero_bit(dcache->inuse, MAPCACHE_ENTRIES, dcache->cursor);
if ( unlikely(idx >= MAPCACHE_ENTRIES) )
{
/* /First/, clean the garbage map and update the inuse list. */
- for ( i = 0; i < ARRAY_SIZE(cache->garbage); i++ )
- {
- unsigned long x = xchg(&cache->garbage[i], 0);
- cache->inuse[i] &= ~x;
+ for ( i = 0; i < ARRAY_SIZE(dcache->garbage); i++ )
+ {
+ unsigned long x = xchg(&dcache->garbage[i], 0);
+ dcache->inuse[i] &= ~x;
}
/* /Second/, flush TLBs. */
perfc_incr(domain_page_tlb_flush);
local_flush_tlb();
- cache->shadow_epoch[vcpu] = ++cache->epoch;
- cache->tlbflush_timestamp = tlbflush_current_time();
-
- idx = find_first_zero_bit(cache->inuse, MAPCACHE_ENTRIES);
+ vcache->shadow_epoch = ++dcache->epoch;
+ dcache->tlbflush_timestamp = tlbflush_current_time();
+
+ idx = find_first_zero_bit(dcache->inuse, MAPCACHE_ENTRIES);
BUG_ON(idx >= MAPCACHE_ENTRIES);
}
- set_bit(idx, cache->inuse);
- cache->cursor = idx + 1;
-
- spin_unlock(&cache->lock);
-
- l1e_write(&cache->l1tab[idx], l1e_from_pfn(mfn, __PAGE_HYPERVISOR));
+ set_bit(idx, dcache->inuse);
+ dcache->cursor = idx + 1;
+
+ spin_unlock(&dcache->lock);
+
+ l1e_write(&dcache->l1tab[idx], l1e_from_pfn(mfn, __PAGE_HYPERVISOR));
out:
va = MAPCACHE_VIRT_START + (idx << PAGE_SHIFT);
@@ -117,7 +118,7 @@ void unmap_domain_page(void *va)
{
unsigned int idx;
struct vcpu *v;
- struct mapcache *cache;
+ struct mapcache_domain *dcache;
unsigned long mfn;
struct vcpu_maphash_entry *hashent;
@@ -128,11 +129,11 @@ void unmap_domain_page(void *va)
v = mapcache_current_vcpu();
- cache = &v->domain->arch.mapcache;
+ dcache = &v->domain->arch.mapcache;
idx = ((unsigned long)va - MAPCACHE_VIRT_START) >> PAGE_SHIFT;
- mfn = l1e_get_pfn(cache->l1tab[idx]);
- hashent = &cache->vcpu_maphash[v->vcpu_id].hash[MAPHASH_HASHFN(mfn)];
+ mfn = l1e_get_pfn(dcache->l1tab[idx]);
+ hashent = &v->arch.mapcache.hash[MAPHASH_HASHFN(mfn)];
if ( hashent->idx == idx )
{
@@ -145,10 +146,10 @@ void unmap_domain_page(void *va)
if ( hashent->idx != MAPHASHENT_NOTINUSE )
{
/* /First/, zap the PTE. */
- ASSERT(l1e_get_pfn(cache->l1tab[hashent->idx]) == hashent->mfn);
- l1e_write(&cache->l1tab[hashent->idx], l1e_empty());
+ ASSERT(l1e_get_pfn(dcache->l1tab[hashent->idx]) == hashent->mfn);
+ l1e_write(&dcache->l1tab[hashent->idx], l1e_empty());
/* /Second/, mark as garbage. */
- set_bit(hashent->idx, cache->garbage);
+ set_bit(hashent->idx, dcache->garbage);
}
/* Add newly-freed mapping to the maphash. */
@@ -158,30 +159,30 @@ void unmap_domain_page(void *va)
else
{
/* /First/, zap the PTE. */
- l1e_write(&cache->l1tab[idx], l1e_empty());
+ l1e_write(&dcache->l1tab[idx], l1e_empty());
/* /Second/, mark as garbage. */
- set_bit(idx, cache->garbage);
- }
-}
-
-void mapcache_init(struct domain *d)
-{
- unsigned int i, j;
- struct vcpu_maphash_entry *hashent;
-
+ set_bit(idx, dcache->garbage);
+ }
+}
+
+void mapcache_domain_init(struct domain *d)
+{
d->arch.mapcache.l1tab = d->arch.mm_perdomain_pt +
(GDT_LDT_MBYTES << (20 - PAGE_SHIFT));
spin_lock_init(&d->arch.mapcache.lock);
+}
+
+void mapcache_vcpu_init(struct vcpu *v)
+{
+ unsigned int i;
+ struct vcpu_maphash_entry *hashent;
/* Mark all maphash entries as not in use. */
- for ( i = 0; i < MAX_VIRT_CPUS; i++ )
- {
- for ( j = 0; j < MAPHASH_ENTRIES; j++ )
- {
- hashent = &d->arch.mapcache.vcpu_maphash[i].hash[j];
- hashent->mfn = ~0UL; /* never valid to map */
- hashent->idx = MAPHASHENT_NOTINUSE;
- }
+ for ( i = 0; i < MAPHASH_ENTRIES; i++ )
+ {
+ hashent = &v->arch.mapcache.hash[i];
+ hashent->mfn = ~0UL; /* never valid to map */
+ hashent->idx = MAPHASHENT_NOTINUSE;
}
}
diff -r 818cc26e3926 -r e1b574bc36b5 xen/include/asm-x86/domain.h
--- a/xen/include/asm-x86/domain.h Tue Oct 02 13:19:25 2007 +0100
+++ b/xen/include/asm-x86/domain.h Tue Oct 02 16:28:58 2007 +0100
@@ -28,17 +28,21 @@ struct trap_bounce {
#define MAPHASH_ENTRIES 8
#define MAPHASH_HASHFN(pfn) ((pfn) & (MAPHASH_ENTRIES-1))
#define MAPHASHENT_NOTINUSE ((u16)~0U)
-struct vcpu_maphash {
+struct mapcache_vcpu {
+ /* Shadow of mapcache_domain.epoch. */
+ unsigned int shadow_epoch;
+
+ /* Lock-free per-VCPU hash of recently-used mappings. */
struct vcpu_maphash_entry {
unsigned long mfn;
uint16_t idx;
uint16_t refcnt;
} hash[MAPHASH_ENTRIES];
-} __cacheline_aligned;
+};
#define MAPCACHE_ORDER 10
#define MAPCACHE_ENTRIES (1 << MAPCACHE_ORDER)
-struct mapcache {
+struct mapcache_domain {
/* The PTEs that provide the mappings, and a cursor into the array. */
l1_pgentry_t *l1tab;
unsigned int cursor;
@@ -47,27 +51,25 @@ struct mapcache {
spinlock_t lock;
/* Garbage mappings are flushed from TLBs in batches called 'epochs'. */
- unsigned int epoch, shadow_epoch[MAX_VIRT_CPUS];
+ unsigned int epoch;
u32 tlbflush_timestamp;
/* Which mappings are in use, and which are garbage to reap next epoch? */
unsigned long inuse[BITS_TO_LONGS(MAPCACHE_ENTRIES)];
unsigned long garbage[BITS_TO_LONGS(MAPCACHE_ENTRIES)];
-
- /* Lock-free per-VCPU hash of recently-used mappings. */
- struct vcpu_maphash vcpu_maphash[MAX_VIRT_CPUS];
-};
-
-extern void mapcache_init(struct domain *);
+};
+
+void mapcache_domain_init(struct domain *);
+void mapcache_vcpu_init(struct vcpu *);
/* x86/64: toggle guest between kernel and user modes. */
-extern void toggle_guest_mode(struct vcpu *);
+void toggle_guest_mode(struct vcpu *);
/*
* Initialise a hypercall-transfer page. The given pointer must be mapped
* in Xen virtual address space (accesses are not validated or checked).
*/
-extern void hypercall_page_initialise(struct domain *d, void *);
+void hypercall_page_initialise(struct domain *d, void *);
/************************************************/
/* shadow paging extension */
@@ -204,7 +206,7 @@ struct arch_domain
#ifdef CONFIG_X86_32
/* map_domain_page() mapping cache. */
- struct mapcache mapcache;
+ struct mapcache_domain mapcache;
#endif
#ifdef CONFIG_COMPAT
@@ -290,7 +292,7 @@ struct arch_vcpu
struct trap_bounce trap_bounce;
/* I/O-port access bitmap. */
- XEN_GUEST_HANDLE(uint8_t) iobmp; /* Guest kernel virtual address of the
bitmap. */
+ XEN_GUEST_HANDLE(uint8_t) iobmp; /* Guest kernel vaddr of the bitmap. */
int iobmp_limit; /* Number of ports represented in the bitmap. */
int iopl; /* Current IOPL for this VCPU. */
@@ -327,6 +329,12 @@ struct arch_vcpu
/* Guest-specified relocation of vcpu_info. */
unsigned long vcpu_info_mfn;
+
+#ifdef CONFIG_X86_32
+ /* map_domain_page() mapping cache. */
+ struct mapcache_vcpu mapcache;
+#endif
+
} __cacheline_aligned;
/* Shorthands to improve code legibility. */
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