Commit 29a56818 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Replace force_pte with a max_map_size attribute 



force_pte is annoyingly limited in what it expresses, and we'd
be better off with a more generic primitive. Introduce max_map_size
instead, which does the trick and can be moved into the vma_info
structure. This firther allows it to reduce the scopes in which
it is mutable.

Tested-by: default avatarFuad Tabba <tabba@google.com>
Reviewed-by: default avatarFuad Tabba <tabba@google.com>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent f8dad960

arch/arm64/kvm/mmu.c

+13 −10
Original line number Diff line number Diff line
@@ -1650,6 +1650,7 @@ struct kvm_s2_fault_vma_info { 
	unsigned long	mmu_seq;

	long		vma_pagesize;

	vm_flags_t	vm_flags;

	unsigned long	max_map_size;

	struct page	*page;

	kvm_pfn_t	pfn;

	gfn_t		gfn;
@@ -1659,14 +1660,18 @@ struct kvm_s2_fault_vma_info { 
};



static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd,

				     struct vm_area_struct *vma, bool *force_pte)

				     struct kvm_s2_fault_vma_info *s2vi,

				     struct vm_area_struct *vma)

{

	short vma_shift;



	if (*force_pte)

	if (memslot_is_logging(s2fd->memslot)) {

		s2vi->max_map_size = PAGE_SIZE;

		vma_shift = PAGE_SHIFT;

	else

	} else {

		s2vi->max_map_size = PUD_SIZE;

		vma_shift = get_vma_page_shift(vma, s2fd->hva);

	}



	switch (vma_shift) {

#ifndef __PAGETABLE_PMD_FOLDED
@@ -1684,7 +1689,7 @@ static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd, 
		fallthrough;

	case CONT_PTE_SHIFT:

		vma_shift = PAGE_SHIFT;

		*force_pte = true;

		s2vi->max_map_size = PAGE_SIZE;

		fallthrough;

	case PAGE_SHIFT:

		break;
@@ -1695,7 +1700,7 @@ static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd, 
	if (s2fd->nested) {

		unsigned long max_map_size;



		max_map_size = *force_pte ? PAGE_SIZE : PUD_SIZE;

		max_map_size = min(s2vi->max_map_size, PUD_SIZE);



		/*

		 * If we're about to create a shadow stage 2 entry, then we
@@ -1713,7 +1718,7 @@ static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd, 
		else if (max_map_size >= PAGE_SIZE && max_map_size < PMD_SIZE)

			max_map_size = PAGE_SIZE;



		*force_pte = (max_map_size == PAGE_SIZE);

		s2vi->max_map_size = max_map_size;

		vma_shift = min_t(short, vma_shift, __ffs(max_map_size));

	}
@@ -1722,7 +1727,6 @@ static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd, 


struct kvm_s2_fault {

	bool s2_force_noncacheable;

	bool force_pte;

	enum kvm_pgtable_prot prot;

};
@@ -1746,7 +1750,7 @@ static int kvm_s2_fault_get_vma_info(const struct kvm_s2_fault_desc *s2fd, 
		return -EFAULT;

	}



	s2vi->vma_pagesize = BIT(kvm_s2_resolve_vma_size(s2fd, vma, &fault->force_pte));

	s2vi->vma_pagesize = BIT(kvm_s2_resolve_vma_size(s2fd, s2vi, vma));



	/*

	 * Both the canonical IPA and fault IPA must be aligned to the
@@ -1931,7 +1935,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd, 
	 * backed by a THP and thus use block mapping if possible.

	 */

	if (mapping_size == PAGE_SIZE &&

	    !(fault->force_pte || fault->s2_force_noncacheable)) {

	    !(s2vi->max_map_size == PAGE_SIZE || fault->s2_force_noncacheable)) {

		if (perm_fault_granule > PAGE_SIZE) {

			mapping_size = perm_fault_granule;

		} else {
@@ -1992,7 +1996,6 @@ static int user_mem_abort(const struct kvm_s2_fault_desc *s2fd) 
	bool perm_fault = kvm_vcpu_trap_is_permission_fault(s2fd->vcpu);

	struct kvm_s2_fault_vma_info s2vi = {};

	struct kvm_s2_fault fault = {

		.force_pte = memslot_is_logging(s2fd->memslot),

		.prot = KVM_PGTABLE_PROT_R,

	};

	void *memcache;