Commit 17eff019 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Refactor THP adjust to prep for changing query 



Refactor transparent_hugepage_adjust() in preparation for walking the
host page tables to identify hugepage mappings, initially for THP pages,
and eventualy for HugeTLB and DAX-backed pages as well.  The latter
cases support 1gb pages, i.e. the adjustment logic needs access to the
max allowed level.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 13c72c06

arch/x86/kvm/mmu/mmu.c

+22 −22
Original line number Diff line number Diff line
@@ -3329,34 +3329,35 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 
	__direct_pte_prefetch(vcpu, sp, sptep);

}



static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,

					gfn_t gfn, kvm_pfn_t *pfnp,

static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,

					int max_level, kvm_pfn_t *pfnp,

					int *levelp)

{

	kvm_pfn_t pfn = *pfnp;

	int level = *levelp;

	kvm_pfn_t mask;



	/*

	 * Check if it's a transparent hugepage. If this would be an

	 * hugetlbfs page, level wouldn't be set to

	 * PT_PAGE_TABLE_LEVEL and there would be no adjustment done

	 * here.

	 */

	if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) &&

	    !kvm_is_zone_device_pfn(pfn) && level == PT_PAGE_TABLE_LEVEL &&

	    kvm_is_transparent_hugepage(pfn)) {

		unsigned long mask;

	if (max_level == PT_PAGE_TABLE_LEVEL || level > PT_PAGE_TABLE_LEVEL)

		return;



	if (is_error_noslot_pfn(pfn) || kvm_is_reserved_pfn(pfn) ||

	    kvm_is_zone_device_pfn(pfn))

		return;



	if (!kvm_is_transparent_hugepage(pfn))

		return;



	level = PT_DIRECTORY_LEVEL;



	/*

	 * mmu_notifier_retry() was successful and mmu_lock is held, so

	 * the pmd can't be split from under us.

	 */

		*levelp = level = PT_DIRECTORY_LEVEL;

	*levelp = level;

	mask = KVM_PAGES_PER_HPAGE(level) - 1;

	VM_BUG_ON((gfn & mask) != (pfn & mask));

	*pfnp = pfn & ~mask;

}

}



static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it,

				       gfn_t gfn, kvm_pfn_t *pfnp, int *levelp)
@@ -3395,8 +3396,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write, 
	if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa)))

		return RET_PF_RETRY;



	if (likely(max_level > PT_PAGE_TABLE_LEVEL))

		transparent_hugepage_adjust(vcpu, gfn, &pfn, &level);

	transparent_hugepage_adjust(vcpu, gfn, max_level, &pfn, &level);



	trace_kvm_mmu_spte_requested(gpa, level, pfn);

	for_each_shadow_entry(vcpu, gpa, it) {

arch/x86/kvm/mmu/paging_tmpl.h

+1 −2
Original line number Diff line number Diff line
@@ -688,8 +688,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr, 
	gfn = gw->gfn | ((addr & PT_LVL_OFFSET_MASK(gw->level)) >> PAGE_SHIFT);

	base_gfn = gfn;



	if (max_level > PT_PAGE_TABLE_LEVEL)

		transparent_hugepage_adjust(vcpu, gw->gfn, &pfn, &hlevel);

	transparent_hugepage_adjust(vcpu, gw->gfn, max_level, &pfn, &hlevel);



	trace_kvm_mmu_spte_requested(addr, gw->level, pfn);

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