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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] Fix the support for PAE pgdirs above 4GB that was introduced in
# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID d5f98d23427a0d256b896fc63ccfd2c1f79e55ba
# Parent 6d476981e3a5da8198f726dfb34904d33dea4f40
Fix the support for PAE pgdirs above 4GB that was introduced in
changeset 10173:954f4dea9da6336aaa35d0706aed55fde7909644.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
xen/arch/x86/domain.c | 2
xen/arch/x86/mm.c | 158 +++++++++++++++++++++++++------------------
xen/include/asm-x86/domain.h | 29 +++++--
xen/include/asm-x86/fixmap.h | 10 +-
4 files changed, 122 insertions(+), 77 deletions(-)
diff -r 6d476981e3a5 -r d5f98d23427a xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c Sun May 28 15:49:17 2006 +0100
+++ b/xen/arch/x86/domain.c Tue May 30 11:44:23 2006 +0100
@@ -146,6 +146,8 @@ struct vcpu *alloc_vcpu_struct(struct do
v->arch.guest_vl4table = __linear_l4_table;
#endif
+ pae_l3_cache_init(&v->arch.pae_l3_cache);
+
return v;
}
diff -r 6d476981e3a5 -r d5f98d23427a xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Sun May 28 15:49:17 2006 +0100
+++ b/xen/arch/x86/mm.c Tue May 30 11:44:23 2006 +0100
@@ -260,38 +260,78 @@ void share_xen_page_with_privileged_gues
share_xen_page_with_guest(page, dom_xen, readonly);
}
+#if defined(CONFIG_X86_PAE)
+
+#ifdef NDEBUG
+/* Only PDPTs above 4GB boundary need to be shadowed in low memory. */
+#define l3tab_needs_shadow(mfn) (mfn >= 0x100000)
+#else
+/* In debug builds we aggressively shadow PDPTs to exercise code paths. */
+#define l3tab_needs_shadow(mfn) ((mfn << PAGE_SHIFT) != __pa(idle_pg_table))
+#endif
+
+static l1_pgentry_t *fix_pae_highmem_pl1e;
+
+/* Cache the address of PAE high-memory fixmap page tables. */
+static int __init cache_pae_fixmap_address(void)
+{
+ unsigned long fixmap_base = fix_to_virt(FIX_PAE_HIGHMEM_0);
+ l2_pgentry_t *pl2e = virt_to_xen_l2e(fixmap_base);
+ fix_pae_highmem_pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(fixmap_base);
+ return 0;
+}
+__initcall(cache_pae_fixmap_address);
+
static void __write_ptbase(unsigned long mfn)
{
-#ifdef CONFIG_X86_PAE
- if ( mfn >= 0x100000 )
- {
- l3_pgentry_t *highmem_l3tab, *lowmem_l3tab;
- struct vcpu *v = current;
- unsigned long flags;
-
- /* Protects against re-entry and against __pae_flush_pgd(). */
- local_irq_save(flags);
-
- /* Pick an unused low-memory L3 cache slot. */
- v->arch.lowmem_l3tab_inuse ^= 1;
- lowmem_l3tab = v->arch.lowmem_l3tab[v->arch.lowmem_l3tab_inuse];
- v->arch.lowmem_l3tab_high_mfn[v->arch.lowmem_l3tab_inuse] = mfn;
-
- /* Map the guest L3 table and copy to the chosen low-memory cache. */
- highmem_l3tab = map_domain_page(mfn);
- memcpy(lowmem_l3tab, highmem_l3tab, sizeof(v->arch.lowmem_l3tab));
- unmap_domain_page(highmem_l3tab);
-
- /* Install the low-memory L3 table in CR3. */
- write_cr3(__pa(lowmem_l3tab));
-
- local_irq_restore(flags);
+ l3_pgentry_t *highmem_l3tab, *lowmem_l3tab;
+ struct pae_l3_cache *cache = ¤t->arch.pae_l3_cache;
+ unsigned int cpu = smp_processor_id();
+
+ /* Fast path 1: does this mfn need a shadow at all? */
+ if ( !l3tab_needs_shadow(mfn) )
+ {
+ write_cr3(mfn << PAGE_SHIFT);
return;
}
-#endif
-
+
+ /* Caching logic is not interrupt safe. */
+ ASSERT(!in_irq());
+
+ /* Fast path 2: is this mfn already cached? */
+ if ( cache->high_mfn == mfn )
+ {
+ write_cr3(__pa(cache->table[cache->inuse_idx]));
+ return;
+ }
+
+ /* Protects against pae_flush_pgd(). */
+ spin_lock(&cache->lock);
+
+ cache->inuse_idx ^= 1;
+ cache->high_mfn = mfn;
+
+ /* Map the guest L3 table and copy to the chosen low-memory cache. */
+ *(fix_pae_highmem_pl1e - cpu) = l1e_from_pfn(mfn, __PAGE_HYPERVISOR);
+ highmem_l3tab = (l3_pgentry_t *)fix_to_virt(FIX_PAE_HIGHMEM_0 + cpu);
+ lowmem_l3tab = cache->table[cache->inuse_idx];
+ memcpy(lowmem_l3tab, highmem_l3tab, sizeof(cache->table[0]));
+ *(fix_pae_highmem_pl1e - cpu) = l1e_empty();
+
+ /* Install the low-memory L3 table in CR3. */
+ write_cr3(__pa(lowmem_l3tab));
+
+ spin_unlock(&cache->lock);
+}
+
+#else /* !CONFIG_X86_PAE */
+
+static void __write_ptbase(unsigned long mfn)
+{
write_cr3(mfn << PAGE_SHIFT);
}
+
+#endif /* !CONFIG_X86_PAE */
void write_ptbase(struct vcpu *v)
{
@@ -804,48 +844,39 @@ static int create_pae_xen_mappings(l3_pg
return 1;
}
-struct pae_flush_pgd {
- unsigned long l3tab_mfn;
- unsigned int l3tab_idx;
- l3_pgentry_t nl3e;
-};
-
-static void __pae_flush_pgd(void *data)
-{
- struct pae_flush_pgd *args = data;
- struct vcpu *v = this_cpu(curr_vcpu);
- int i = v->arch.lowmem_l3tab_inuse;
- intpte_t _ol3e, _nl3e, _pl3e;
- l3_pgentry_t *l3tab_ptr;
-
- ASSERT(!local_irq_is_enabled());
-
- if ( v->arch.lowmem_l3tab_high_mfn[i] != args->l3tab_mfn )
- return;
-
- l3tab_ptr = &v->arch.lowmem_l3tab[i][args->l3tab_idx];
-
- _ol3e = l3e_get_intpte(*l3tab_ptr);
- _nl3e = l3e_get_intpte(args->nl3e);
- _pl3e = cmpxchg((intpte_t *)l3tab_ptr, _ol3e, _nl3e);
- BUG_ON(_pl3e != _ol3e);
-}
-
/* Flush a pgdir update into low-memory caches. */
static void pae_flush_pgd(
unsigned long mfn, unsigned int idx, l3_pgentry_t nl3e)
{
struct domain *d = page_get_owner(mfn_to_page(mfn));
- struct pae_flush_pgd args = {
- .l3tab_mfn = mfn,
- .l3tab_idx = idx,
- .nl3e = nl3e };
+ struct vcpu *v;
+ intpte_t _ol3e, _nl3e, _pl3e;
+ l3_pgentry_t *l3tab_ptr;
+ struct pae_l3_cache *cache;
/* If below 4GB then the pgdir is not shadowed in low memory. */
- if ( mfn < 0x100000 )
+ if ( !l3tab_needs_shadow(mfn) )
return;
- on_selected_cpus(d->domain_dirty_cpumask, __pae_flush_pgd, &args, 1, 1);
+ for_each_vcpu ( d, v )
+ {
+ cache = &v->arch.pae_l3_cache;
+
+ spin_lock(&cache->lock);
+
+ if ( cache->high_mfn == mfn )
+ {
+ l3tab_ptr = &cache->table[cache->inuse_idx][idx];
+ _ol3e = l3e_get_intpte(*l3tab_ptr);
+ _nl3e = l3e_get_intpte(nl3e);
+ _pl3e = cmpxchg((intpte_t *)l3tab_ptr, _ol3e, _nl3e);
+ BUG_ON(_pl3e != _ol3e);
+ }
+
+ spin_unlock(&cache->lock);
+ }
+
+ flush_tlb_mask(d->domain_dirty_cpumask);
}
static inline int l1_backptr(
@@ -3708,11 +3739,10 @@ int map_pages_to_xen(
}
void __set_fixmap(
- enum fixed_addresses idx, unsigned long p, unsigned long flags)
-{
- if ( unlikely(idx >= __end_of_fixed_addresses) )
- BUG();
- map_pages_to_xen(fix_to_virt(idx), p >> PAGE_SHIFT, 1, flags);
+ enum fixed_addresses idx, unsigned long mfn, unsigned long flags)
+{
+ BUG_ON(idx >= __end_of_fixed_addresses);
+ map_pages_to_xen(fix_to_virt(idx), mfn, 1, flags);
}
#ifdef MEMORY_GUARD
diff -r 6d476981e3a5 -r d5f98d23427a xen/include/asm-x86/domain.h
--- a/xen/include/asm-x86/domain.h Sun May 28 15:49:17 2006 +0100
+++ b/xen/include/asm-x86/domain.h Tue May 30 11:44:23 2006 +0100
@@ -114,23 +114,32 @@ struct arch_domain
unsigned long first_reserved_pfn;
} __cacheline_aligned;
-struct arch_vcpu
-{
- /* Needs 16-byte aligment for FXSAVE/FXRSTOR. */
- struct vcpu_guest_context guest_context
- __attribute__((__aligned__(16)));
-
#ifdef CONFIG_X86_PAE
+struct pae_l3_cache {
/*
* Two low-memory (<4GB) PAE L3 tables, used as fallback when the guest
* supplies a >=4GB PAE L3 table. We need two because we cannot set up
* an L3 table while we are currently running on it (without using
* expensive atomic 64-bit operations).
*/
- l3_pgentry_t lowmem_l3tab[2][4] __attribute__((__aligned__(32)));
- unsigned long lowmem_l3tab_high_mfn[2]; /* The >=4GB MFN being shadowed. */
- unsigned int lowmem_l3tab_inuse; /* Which lowmem_l3tab is in use? */
-#endif
+ l3_pgentry_t table[2][4] __attribute__((__aligned__(32)));
+ unsigned long high_mfn; /* The >=4GB MFN being shadowed. */
+ unsigned int inuse_idx; /* Which of the two cache slots is in use? */
+ spinlock_t lock;
+};
+#define pae_l3_cache_init(c) spin_lock_init(&(c)->lock)
+#else /* !CONFIG_X86_PAE */
+struct pae_l3_cache { };
+#define pae_l3_cache_init(c) ((void)0)
+#endif
+
+struct arch_vcpu
+{
+ /* Needs 16-byte aligment for FXSAVE/FXRSTOR. */
+ struct vcpu_guest_context guest_context
+ __attribute__((__aligned__(16)));
+
+ struct pae_l3_cache pae_l3_cache;
unsigned long flags; /* TF_ */
diff -r 6d476981e3a5 -r d5f98d23427a xen/include/asm-x86/fixmap.h
--- a/xen/include/asm-x86/fixmap.h Sun May 28 15:49:17 2006 +0100
+++ b/xen/include/asm-x86/fixmap.h Tue May 30 11:44:23 2006 +0100
@@ -25,6 +25,10 @@
* from the end of virtual memory backwards.
*/
enum fixed_addresses {
+#ifdef CONFIG_X86_PAE
+ FIX_PAE_HIGHMEM_0,
+ FIX_PAE_HIGHMEM_END = FIX_PAE_HIGHMEM_0 + NR_CPUS-1,
+#endif
FIX_APIC_BASE,
FIX_IO_APIC_BASE_0,
FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1,
@@ -40,13 +44,13 @@ enum fixed_addresses {
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
extern void __set_fixmap(
- enum fixed_addresses idx, unsigned long p, unsigned long flags);
+ enum fixed_addresses idx, unsigned long mfn, unsigned long flags);
#define set_fixmap(idx, phys) \
- __set_fixmap(idx, phys, PAGE_HYPERVISOR)
+ __set_fixmap(idx, (phys)>>PAGE_SHIFT, PAGE_HYPERVISOR)
#define set_fixmap_nocache(idx, phys) \
- __set_fixmap(idx, phys, PAGE_HYPERVISOR_NOCACHE)
+ __set_fixmap(idx, (phys)>>PAGE_SHIFT, PAGE_HYPERVISOR_NOCACHE)
#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
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