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KVM: MMU: Move set_pte() into guest paging mode independent code
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As set_pte() no longer references either a gpte or the guest walker, we can
move it out of paging mode dependent code (which compiles twice and is
generally nasty).

Signed-off-by: Avi Kivity <avi@qumranet.com>
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Avi Kivity committed Jan 30, 2008
1 parent 2fbf4cf commit 1c4f1fd
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Showing 2 changed files with 88 additions and 88 deletions.
83 changes: 83 additions & 0 deletions drivers/kvm/mmu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -879,6 +879,89 @@ struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
return gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
}

static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
unsigned pt_access, unsigned pte_access,
int user_fault, int write_fault, int dirty,
int *ptwrite, gfn_t gfn)
{
u64 spte;
int was_rmapped = is_rmap_pte(*shadow_pte);
struct page *page;

pgprintk("%s: spte %llx gpte %llx access %x write_fault %d"
" user_fault %d gfn %lx\n",
__FUNCTION__, *shadow_pte, (u64)gpte, pt_access,
write_fault, user_fault, gfn);

/*
* We don't set the accessed bit, since we sometimes want to see
* whether the guest actually used the pte (in order to detect
* demand paging).
*/
spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
if (!dirty)
pte_access &= ~ACC_WRITE_MASK;
if (!(pte_access & ACC_EXEC_MASK))
spte |= PT64_NX_MASK;

page = gfn_to_page(vcpu->kvm, gfn);

spte |= PT_PRESENT_MASK;
if (pte_access & ACC_USER_MASK)
spte |= PT_USER_MASK;

if (is_error_page(page)) {
set_shadow_pte(shadow_pte,
shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
kvm_release_page_clean(page);
return;
}

spte |= page_to_phys(page);

if ((pte_access & ACC_WRITE_MASK)
|| (write_fault && !is_write_protection(vcpu) && !user_fault)) {
struct kvm_mmu_page *shadow;

spte |= PT_WRITABLE_MASK;
if (user_fault) {
mmu_unshadow(vcpu->kvm, gfn);
goto unshadowed;
}

shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
if (shadow) {
pgprintk("%s: found shadow page for %lx, marking ro\n",
__FUNCTION__, gfn);
pte_access &= ~ACC_WRITE_MASK;
if (is_writeble_pte(spte)) {
spte &= ~PT_WRITABLE_MASK;
kvm_x86_ops->tlb_flush(vcpu);
}
if (write_fault)
*ptwrite = 1;
}
}

unshadowed:

if (pte_access & ACC_WRITE_MASK)
mark_page_dirty(vcpu->kvm, gfn);

pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
set_shadow_pte(shadow_pte, spte);
page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
if (!was_rmapped) {
rmap_add(vcpu, shadow_pte, gfn);
if (!is_rmap_pte(*shadow_pte))
kvm_release_page_clean(page);
}
else
kvm_release_page_clean(page);
if (!ptwrite || !*ptwrite)
vcpu->last_pte_updated = shadow_pte;
}

static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
{
}
Expand Down
93 changes: 5 additions & 88 deletions drivers/kvm/paging_tmpl.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -235,89 +235,6 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
return 0;
}

static void FNAME(set_pte)(struct kvm_vcpu *vcpu, u64 *shadow_pte,
unsigned pt_access, unsigned pte_access,
int user_fault, int write_fault, int dirty,
int *ptwrite, gfn_t gfn)
{
u64 spte;
int was_rmapped = is_rmap_pte(*shadow_pte);
struct page *page;

pgprintk("%s: spte %llx gpte %llx access %x write_fault %d"
" user_fault %d gfn %lx\n",
__FUNCTION__, *shadow_pte, (u64)gpte, pt_access,
write_fault, user_fault, gfn);

/*
* We don't set the accessed bit, since we sometimes want to see
* whether the guest actually used the pte (in order to detect
* demand paging).
*/
spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
if (!dirty)
pte_access &= ~ACC_WRITE_MASK;
if (!(pte_access & ACC_EXEC_MASK))
spte |= PT64_NX_MASK;

page = gfn_to_page(vcpu->kvm, gfn);

spte |= PT_PRESENT_MASK;
if (pte_access & ACC_USER_MASK)
spte |= PT_USER_MASK;

if (is_error_page(page)) {
set_shadow_pte(shadow_pte,
shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
kvm_release_page_clean(page);
return;
}

spte |= page_to_phys(page);

if ((pte_access & ACC_WRITE_MASK)
|| (write_fault && !is_write_protection(vcpu) && !user_fault)) {
struct kvm_mmu_page *shadow;

spte |= PT_WRITABLE_MASK;
if (user_fault) {
mmu_unshadow(vcpu->kvm, gfn);
goto unshadowed;
}

shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
if (shadow) {
pgprintk("%s: found shadow page for %lx, marking ro\n",
__FUNCTION__, gfn);
pte_access &= ~ACC_WRITE_MASK;
if (is_writeble_pte(spte)) {
spte &= ~PT_WRITABLE_MASK;
kvm_x86_ops->tlb_flush(vcpu);
}
if (write_fault)
*ptwrite = 1;
}
}

unshadowed:

if (pte_access & ACC_WRITE_MASK)
mark_page_dirty(vcpu->kvm, gfn);

pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
set_shadow_pte(shadow_pte, spte);
page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
if (!was_rmapped) {
rmap_add(vcpu, shadow_pte, gfn);
if (!is_rmap_pte(*shadow_pte))
kvm_release_page_clean(page);
}
else
kvm_release_page_clean(page);
if (!ptwrite || !*ptwrite)
vcpu->last_pte_updated = shadow_pte;
}

static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
u64 *spte, const void *pte, int bytes,
int offset_in_pte)
Expand All @@ -335,8 +252,8 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
return;
pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte);
pte_access = page->role.access & FNAME(gpte_access)(vcpu, gpte);
FNAME(set_pte)(vcpu, spte, page->role.access, pte_access, 0, 0,
gpte & PT_DIRTY_MASK, NULL, gpte_to_gfn(gpte));
mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
gpte & PT_DIRTY_MASK, NULL, gpte_to_gfn(gpte));
}

/*
Expand Down Expand Up @@ -399,9 +316,9 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
*shadow_ent = shadow_pte;
}

FNAME(set_pte)(vcpu, shadow_ent, access, walker->pte_access & access,
user_fault, write_fault, walker->pte & PT_DIRTY_MASK,
ptwrite, walker->gfn);
mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access,
user_fault, write_fault, walker->pte & PT_DIRTY_MASK,
ptwrite, walker->gfn);

return shadow_ent;
}
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