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yaml
---
r: 45254
b: refs/heads/master
c: cd4a4e5
h: refs/heads/master
v: v3
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Avi Kivity authored and Linus Torvalds committed Jan 6, 2007
1 parent d9007ae commit 6f21df8
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Showing 5 changed files with 143 additions and 14 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 399badf315bd4dd571b4b3b7cf666d9a2af40229
refs/heads/master: cd4a4e5374110444dc38831af517e51ff5a053c3
1 change: 1 addition & 0 deletions trunk/drivers/kvm/kvm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -236,6 +236,7 @@ struct kvm {
struct kvm_vcpu vcpus[KVM_MAX_VCPUS];
int memory_config_version;
int busy;
unsigned long rmap_overflow;
};

struct kvm_stat {
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1 change: 1 addition & 0 deletions trunk/drivers/kvm/kvm_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -638,6 +638,7 @@ static int kvm_dev_ioctl_set_memory_region(struct kvm *kvm,
| __GFP_ZERO);
if (!new.phys_mem[i])
goto out_free;
new.phys_mem[i]->private = 0;
}
}

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152 changes: 139 additions & 13 deletions trunk/drivers/kvm/mmu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@
#include "kvm.h"

#define pgprintk(x...) do { } while (0)
#define rmap_printk(x...) do { } while (0)

#define ASSERT(x) \
if (!(x)) { \
Expand Down Expand Up @@ -125,6 +126,13 @@
#define PT_DIRECTORY_LEVEL 2
#define PT_PAGE_TABLE_LEVEL 1

#define RMAP_EXT 4

struct kvm_rmap_desc {
u64 *shadow_ptes[RMAP_EXT];
struct kvm_rmap_desc *more;
};

static int is_write_protection(struct kvm_vcpu *vcpu)
{
return vcpu->cr0 & CR0_WP_MASK;
Expand All @@ -150,6 +158,120 @@ static int is_io_pte(unsigned long pte)
return pte & PT_SHADOW_IO_MARK;
}

static int is_rmap_pte(u64 pte)
{
return (pte & (PT_WRITABLE_MASK | PT_PRESENT_MASK))
== (PT_WRITABLE_MASK | PT_PRESENT_MASK);
}

/*
* Reverse mapping data structures:
*
* If page->private bit zero is zero, then page->private points to the
* shadow page table entry that points to page_address(page).
*
* If page->private bit zero is one, (then page->private & ~1) points
* to a struct kvm_rmap_desc containing more mappings.
*/
static void rmap_add(struct kvm *kvm, u64 *spte)
{
struct page *page;
struct kvm_rmap_desc *desc;
int i;

if (!is_rmap_pte(*spte))
return;
page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
if (!page->private) {
rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
page->private = (unsigned long)spte;
} else if (!(page->private & 1)) {
rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
desc = kzalloc(sizeof *desc, GFP_NOWAIT);
if (!desc)
BUG(); /* FIXME: return error */
desc->shadow_ptes[0] = (u64 *)page->private;
desc->shadow_ptes[1] = spte;
page->private = (unsigned long)desc | 1;
} else {
rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
desc = (struct kvm_rmap_desc *)(page->private & ~1ul);
while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
desc = desc->more;
if (desc->shadow_ptes[RMAP_EXT-1]) {
desc->more = kzalloc(sizeof *desc->more, GFP_NOWAIT);
if (!desc->more)
BUG(); /* FIXME: return error */
desc = desc->more;
}
for (i = 0; desc->shadow_ptes[i]; ++i)
;
desc->shadow_ptes[i] = spte;
}
}

static void rmap_desc_remove_entry(struct page *page,
struct kvm_rmap_desc *desc,
int i,
struct kvm_rmap_desc *prev_desc)
{
int j;

for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
;
desc->shadow_ptes[i] = desc->shadow_ptes[j];
desc->shadow_ptes[j] = 0;
if (j != 0)
return;
if (!prev_desc && !desc->more)
page->private = (unsigned long)desc->shadow_ptes[0];
else
if (prev_desc)
prev_desc->more = desc->more;
else
page->private = (unsigned long)desc->more | 1;
kfree(desc);
}

static void rmap_remove(struct kvm *kvm, u64 *spte)
{
struct page *page;
struct kvm_rmap_desc *desc;
struct kvm_rmap_desc *prev_desc;
int i;

if (!is_rmap_pte(*spte))
return;
page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
if (!page->private) {
printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
BUG();
} else if (!(page->private & 1)) {
rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
if ((u64 *)page->private != spte) {
printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
spte, *spte);
BUG();
}
page->private = 0;
} else {
rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
desc = (struct kvm_rmap_desc *)(page->private & ~1ul);
prev_desc = NULL;
while (desc) {
for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
if (desc->shadow_ptes[i] == spte) {
rmap_desc_remove_entry(page, desc, i,
prev_desc);
return;
}
prev_desc = desc;
desc = desc->more;
}
BUG();
}
}

static void kvm_mmu_free_page(struct kvm_vcpu *vcpu, hpa_t page_hpa)
{
struct kvm_mmu_page *page_head = page_header(page_hpa);
Expand Down Expand Up @@ -229,27 +351,27 @@ hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva)
static void release_pt_page_64(struct kvm_vcpu *vcpu, hpa_t page_hpa,
int level)
{
u64 *pos;
u64 *end;

ASSERT(vcpu);
ASSERT(VALID_PAGE(page_hpa));
ASSERT(level <= PT64_ROOT_LEVEL && level > 0);

if (level == 1)
memset(__va(page_hpa), 0, PAGE_SIZE);
else {
u64 *pos;
u64 *end;
for (pos = __va(page_hpa), end = pos + PT64_ENT_PER_PAGE;
pos != end; pos++) {
u64 current_ent = *pos;

for (pos = __va(page_hpa), end = pos + PT64_ENT_PER_PAGE;
pos != end; pos++) {
u64 current_ent = *pos;

*pos = 0;
if (is_present_pte(current_ent))
if (is_present_pte(current_ent)) {
if (level != 1)
release_pt_page_64(vcpu,
current_ent &
PT64_BASE_ADDR_MASK,
level - 1);
else
rmap_remove(vcpu->kvm, pos);
}
*pos = 0;
}
kvm_mmu_free_page(vcpu, page_hpa);
}
Expand All @@ -275,6 +397,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
page_header_update_slot(vcpu->kvm, table, v);
table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
PT_USER_MASK;
rmap_add(vcpu->kvm, &table[index]);
return 0;
}

Expand Down Expand Up @@ -437,6 +560,7 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu,
} else {
*shadow_pte |= paddr;
page_header_update_slot(vcpu->kvm, shadow_pte, gaddr);
rmap_add(vcpu->kvm, shadow_pte);
}
}

Expand Down Expand Up @@ -489,6 +613,7 @@ static void paging_inval_page(struct kvm_vcpu *vcpu, gva_t addr)
u64 *table = __va(page_addr);

if (level == PT_PAGE_TABLE_LEVEL ) {
rmap_remove(vcpu->kvm, &table[index]);
table[index] = 0;
return;
}
Expand Down Expand Up @@ -679,8 +804,9 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
pt = __va(page->page_hpa);
for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
/* avoid RMW */
if (pt[i] & PT_WRITABLE_MASK)
if (pt[i] & PT_WRITABLE_MASK) {
rmap_remove(kvm, &pt[i]);
pt[i] &= ~PT_WRITABLE_MASK;

}
}
}
1 change: 1 addition & 0 deletions trunk/drivers/kvm/paging_tmpl.h
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Original file line number Diff line number Diff line change
Expand Up @@ -261,6 +261,7 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
mark_page_dirty(vcpu->kvm, gfn);
*shadow_ent |= PT_WRITABLE_MASK;
*guest_ent |= PT_DIRTY_MASK;
rmap_add(vcpu->kvm, shadow_ent);

return 1;
}
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