[PATCH 4/8] kvm/mmu: make rmap code aware of mapping levels

Joerg Roedel
2009-06-19T13:18:46Z

This patch removes the largepage parameter from the rmap_add function.
Together with rmap_remove this function now uses the role.level field to
find determine if the page is a huge page.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
arch/x86/kvm/mmu.c | 53 +++++++++++++++++++++++++++------------------------
1 files changed, 28 insertions(+), 25 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 3fa6009..0ef947d 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -511,19 +511,19 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
* Note: gfn must be unaliased before this function get called
*/

-static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int lpage)
+static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level)
{
struct kvm_memory_slot *slot;
unsigned long idx;

slot = gfn_to_memslot(kvm, gfn);
- if (!lpage)
+ if (likely(level == PT_PAGE_TABLE_LEVEL))
return &slot->rmap[gfn - slot->base_gfn];

- idx = (gfn / KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL)) -
- (slot->base_gfn / KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL));
+ idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
+ (slot->base_gfn / KVM_PAGES_PER_HPAGE(level));

- return &slot->lpage_info[0][idx].rmap_pde;
+ return &slot->lpage_info[level - 2][idx].rmap_pde;
}

/*
@@ -535,7 +535,7 @@ static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int lpage)
* If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
* containing more mappings.
*/
-static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn, int lpage)
+static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
{
struct kvm_mmu_page *sp;
struct kvm_rmap_desc *desc;
@@ -547,7 +547,7 @@ static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn, int lpage)
gfn = unalias_gfn(vcpu->kvm, gfn);
sp = page_header(__pa(spte));
sp->gfns[spte - sp->spt] = gfn;
- rmapp = gfn_to_rmap(vcpu->kvm, gfn, lpage);
+ rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
if (!*rmapp) {
rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
*rmapp = (unsigned long)spte;
@@ -614,7 +614,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
kvm_release_pfn_dirty(pfn);
else
kvm_release_pfn_clean(pfn);
- rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], is_large_pte(*spte));
+ rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], sp->role.level);
if (!*rmapp) {
printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
BUG();
@@ -677,10 +677,10 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
{
unsigned long *rmapp;
u64 *spte;
- int write_protected = 0;
+ int i, write_protected = 0;

gfn = unalias_gfn(kvm, gfn);
- rmapp = gfn_to_rmap(kvm, gfn, 0);
+ rmapp = gfn_to_rmap(kvm, gfn, PT_PAGE_TABLE_LEVEL);

spte = rmap_next(kvm, rmapp, NULL);
while (spte) {
@@ -702,21 +702,24 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
}

/* check for huge page mappings */
- rmapp = gfn_to_rmap(kvm, gfn, 1);
- spte = rmap_next(kvm, rmapp, NULL);
- while (spte) {
- BUG_ON(!spte);
- BUG_ON(!(*spte & PT_PRESENT_MASK));
- BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
- pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
- if (is_writeble_pte(*spte)) {
- rmap_remove(kvm, spte);
- --kvm->stat.lpages;
- __set_spte(spte, shadow_trap_nonpresent_pte);
- spte = NULL;
- write_protected = 1;
+ for (i = PT_DIRECTORY_LEVEL;
+ i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+ rmapp = gfn_to_rmap(kvm, gfn, i);
+ spte = rmap_next(kvm, rmapp, NULL);
+ while (spte) {
+ BUG_ON(!spte);
+ BUG_ON(!(*spte & PT_PRESENT_MASK));
+ BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
+ pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
+ if (is_writeble_pte(*spte)) {
+ rmap_remove(kvm, spte);
+ --kvm->stat.lpages;
+ __set_spte(spte, shadow_trap_nonpresent_pte);
+ spte = NULL;
+ write_protected = 1;
+ }
+ spte = rmap_next(kvm, rmapp, spte);
}
- spte = rmap_next(kvm, rmapp, spte);
}

return write_protected;
@@ -1823,7 +1826,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,

page_header_update_slot(vcpu->kvm, sptep, gfn);
if (!was_rmapped) {
- rmap_add(vcpu, sptep, gfn, largepage);
+ rmap_add(vcpu, sptep, gfn);
if (!is_rmap_spte(*sptep))
kvm_release_pfn_clean(pfn);
} else {
--
1.6.3.1