Commit e5f98a68 authored by Claudio Imbrenda's avatar Claudio Imbrenda
Browse files

KVM: s390: Add some helper functions needed for vSIE 



Implement gmap_protect_asce_top_level(), which was a stub. This
function was a stub due to cross dependencies with other patches.

Acked-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
parent e907ae53

arch/s390/kvm/gmap.c

+72 −2
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include "dat.h"

#include "gmap.h"

#include "kvm-s390.h"

#include "faultin.h"



static inline bool kvm_s390_is_in_sie(struct kvm_vcpu *vcpu)

{
@@ -1091,10 +1092,79 @@ static struct gmap *gmap_find_shadow(struct gmap *parent, union asce asce, int e 
	return NULL;

}



#define CRST_TABLE_PAGES (_CRST_TABLE_SIZE / PAGE_SIZE)

struct gmap_protect_asce_top_level {

	unsigned long seq;

	struct guest_fault f[CRST_TABLE_PAGES];

};



static inline int __gmap_protect_asce_top_level(struct kvm_s390_mmu_cache *mc, struct gmap *sg,

						struct gmap_protect_asce_top_level *context)

{

	int rc, i;



	guard(write_lock)(&sg->kvm->mmu_lock);



	if (kvm_s390_array_needs_retry_safe(sg->kvm, context->seq, context->f))

		return -EAGAIN;



	scoped_guard(spinlock, &sg->parent->children_lock) {

		for (i = 0; i < CRST_TABLE_PAGES; i++) {

			if (!context->f[i].valid)

				continue;

			rc = gmap_protect_rmap(mc, sg, context->f[i].gfn, 0, context->f[i].pfn,

					       TABLE_TYPE_REGION1 + 1, context->f[i].writable);

			if (rc)

				return rc;

		}

		gmap_add_child(sg->parent, sg);

	}



	kvm_s390_release_faultin_array(sg->kvm, context->f, false);

	return 0;

}



static inline int _gmap_protect_asce_top_level(struct kvm_s390_mmu_cache *mc, struct gmap *sg,

					       struct gmap_protect_asce_top_level *context)

{

	int rc;



	if (kvm_s390_array_needs_retry_unsafe(sg->kvm, context->seq, context->f))

		return -EAGAIN;

	do {

		rc = kvm_s390_mmu_cache_topup(mc);

		if (rc)

			return rc;

		rc = radix_tree_preload(GFP_KERNEL);

		if (rc)

			return rc;

		rc = __gmap_protect_asce_top_level(mc, sg, context);

		radix_tree_preload_end();

	} while (rc == -ENOMEM);



	return rc;

}



static int gmap_protect_asce_top_level(struct kvm_s390_mmu_cache *mc, struct gmap *sg)

{

	KVM_BUG_ON(1, sg->kvm);

	return -EINVAL;

	struct gmap_protect_asce_top_level context = {};

	union asce asce = sg->guest_asce;

	int rc;



	KVM_BUG_ON(!is_shadow(sg), sg->kvm);



	context.seq = sg->kvm->mmu_invalidate_seq;

	/* Pairs with the smp_wmb() in kvm_mmu_invalidate_end(). */

	smp_rmb();



	rc = kvm_s390_get_guest_pages(sg->kvm, context.f, asce.rsto, asce.dt + 1, false);

	if (rc > 0)

		rc = -EFAULT;

	if (!rc)

		rc = _gmap_protect_asce_top_level(mc, sg, &context);

	if (rc)

		kvm_s390_release_faultin_array(sg->kvm, context.f, true);

	return rc;

}



/**