Commit 1c4f1fd6 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: MMU: Move set_pte() into guest paging mode independent code 



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: default avatarAvi Kivity <avi@qumranet.com>
parent 2fbf4cf1

drivers/kvm/mmu.c

+83 −0
Original line number Diff line number Diff line
@@ -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)

{

}

drivers/kvm/paging_tmpl.h

+5 −88
Original line number Diff line number Diff line
@@ -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)
@@ -335,7 +252,7 @@ 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,

	mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,

		     gpte & PT_DIRTY_MASK, NULL, gpte_to_gfn(gpte));

}
@@ -399,7 +316,7 @@ 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,

	mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access,

		     user_fault, write_fault, walker->pte & PT_DIRTY_MASK,

		     ptwrite, walker->gfn);