Commit 029499b4 authored by Takuya Yoshikawa's avatar Takuya Yoshikawa Committed by Paolo Bonzini
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KVM: x86: MMU: Make mmu_set_spte() return emulate value 



mmu_set_spte()'s code is based on the assumption that the emulate
parameter has a valid pointer value if set_spte() returns true and
write_fault is not zero.  In other cases, emulate may be NULL, so a
NULL-check is needed.

Stop passing emulate pointer and make mmu_set_spte() return the emulate
value instead to clean up this complex interface.  Prefetch functions
can just throw away the return value.

Signed-off-by: default avatarTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent fd951457

arch/x86/kvm/mmu.c

+14 −13
Original line number Diff line number Diff line
@@ -2564,13 +2564,13 @@ done: 
	return ret;

}



static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,

			 unsigned pte_access, int write_fault, int *emulate,

			 int level, gfn_t gfn, pfn_t pfn, bool speculative,

			 bool host_writable)

static bool mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,

			 int write_fault, int level, gfn_t gfn, pfn_t pfn,

			 bool speculative, bool host_writable)

{

	int was_rmapped = 0;

	int rmap_count;

	bool emulate = false;



	pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__,

		 *sptep, write_fault, gfn);
@@ -2600,12 +2600,12 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, 
	if (set_spte(vcpu, sptep, pte_access, level, gfn, pfn, speculative,

	      true, host_writable)) {

		if (write_fault)

			*emulate = 1;

			emulate = true;

		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);

	}



	if (unlikely(is_mmio_spte(*sptep) && emulate))

		*emulate = 1;

	if (unlikely(is_mmio_spte(*sptep)))

		emulate = true;



	pgprintk("%s: setting spte %llx\n", __func__, *sptep);

	pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
@@ -2624,6 +2624,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, 
	}



	kvm_release_pfn_clean(pfn);



	return emulate;

}



static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn,
@@ -2658,9 +2660,8 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, 
		return -1;



	for (i = 0; i < ret; i++, gfn++, start++)

		mmu_set_spte(vcpu, start, access, 0, NULL,

			     sp->role.level, gfn, page_to_pfn(pages[i]),

			     true, true);

		mmu_set_spte(vcpu, start, access, 0, sp->role.level, gfn,

			     page_to_pfn(pages[i]), true, true);



	return 0;

}
@@ -2721,9 +2722,9 @@ static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable, 


	for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {

		if (iterator.level == level) {

			mmu_set_spte(vcpu, iterator.sptep, ACC_ALL,

				     write, &emulate, level, gfn, pfn,

				     prefault, map_writable);

			emulate = mmu_set_spte(vcpu, iterator.sptep, ACC_ALL,

					       write, level, gfn, pfn, prefault,

					       map_writable);

			direct_pte_prefetch(vcpu, iterator.sptep);

			++vcpu->stat.pf_fixed;

			break;

arch/x86/kvm/paging_tmpl.h

+5 −5
Original line number Diff line number Diff line
@@ -475,8 +475,8 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 
	 * we call mmu_set_spte() with host_writable = true because

	 * pte_prefetch_gfn_to_pfn always gets a writable pfn.

	 */

	mmu_set_spte(vcpu, spte, pte_access, 0, NULL, PT_PAGE_TABLE_LEVEL,

		     gfn, pfn, true, true);

	mmu_set_spte(vcpu, spte, pte_access, 0, PT_PAGE_TABLE_LEVEL, gfn, pfn,

		     true, true);



	return true;

}
@@ -556,7 +556,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, 
	struct kvm_mmu_page *sp = NULL;

	struct kvm_shadow_walk_iterator it;

	unsigned direct_access, access = gw->pt_access;

	int top_level, emulate = 0;

	int top_level, emulate;



	direct_access = gw->pte_access;
@@ -622,7 +622,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, 
	}



	clear_sp_write_flooding_count(it.sptep);

	mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault, &emulate,

	emulate = mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault,

			       it.level, gw->gfn, pfn, prefault, map_writable);

	FNAME(pte_prefetch)(vcpu, gw, it.sptep);

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