Commit 63c57544 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Invert @can_unsync and renamed to @synchronizing 



Invert the polarity of "can_unsync" and rename the parameter to
"synchronizing" to allow a future change to set the Accessed bit if KVM
is synchronizing an existing SPTE.  Querying "can_unsync" in that case is
nonsensical, as the fact that KVM can't unsync SPTEs doesn't provide any
justification for setting the Accessed bit.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Tested-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-7-seanjc@google.com>
parent 6385d01e

arch/x86/kvm/mmu/mmu.c

+6 −6
Original line number Diff line number Diff line
@@ -2802,7 +2802,7 @@ static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) 
 * be write-protected.

 */

int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,

			    gfn_t gfn, bool can_unsync, bool prefetch)

			    gfn_t gfn, bool synchronizing, bool prefetch)

{

	struct kvm_mmu_page *sp;

	bool locked = false;
@@ -2817,12 +2817,12 @@ int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 


	/*

	 * The page is not write-tracked, mark existing shadow pages unsync

	 * unless KVM is synchronizing an unsync SP (can_unsync = false).  In

	 * that case, KVM must complete emulation of the guest TLB flush before

	 * allowing shadow pages to become unsync (writable by the guest).

	 * unless KVM is synchronizing an unsync SP.  In that case, KVM must

	 * complete emulation of the guest TLB flush before allowing shadow

	 * pages to become unsync (writable by the guest).

	 */

	for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) {

		if (!can_unsync)

		if (synchronizing)

			return -EPERM;



		if (sp->unsync)
@@ -2948,7 +2948,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot, 
	}



	wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch,

			   true, host_writable, &spte);

			   false, host_writable, &spte);



	if (*sptep == spte) {

		ret = RET_PF_SPURIOUS;

arch/x86/kvm/mmu/mmu_internal.h

+1 −1
Original line number Diff line number Diff line
@@ -164,7 +164,7 @@ static inline gfn_t gfn_round_for_level(gfn_t gfn, int level) 
}



int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,

			    gfn_t gfn, bool can_unsync, bool prefetch);

			    gfn_t gfn, bool synchronizing, bool prefetch);



void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);

void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);

arch/x86/kvm/mmu/paging_tmpl.h

+1 −1
Original line number Diff line number Diff line
@@ -963,7 +963,7 @@ static int FNAME(sync_spte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int 
	host_writable = spte & shadow_host_writable_mask;

	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);

	make_spte(vcpu, sp, slot, pte_access, gfn,

		  spte_to_pfn(spte), spte, true, false,

		  spte_to_pfn(spte), spte, true, true,

		  host_writable, &spte);



	return mmu_spte_update(sptep, spte);

arch/x86/kvm/mmu/spte.c

+2 −2
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ bool spte_has_volatile_bits(u64 spte) 
bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,

	       const struct kvm_memory_slot *slot,

	       unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn,

	       u64 old_spte, bool prefetch, bool can_unsync,

	       u64 old_spte, bool prefetch, bool synchronizing,

	       bool host_writable, u64 *new_spte)

{

	int level = sp->role.level;
@@ -248,7 +248,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, 
		 * e.g. it's write-tracked (upper-level SPs) or has one or more

		 * shadow pages and unsync'ing pages is not allowed.

		 */

		if (mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, can_unsync, prefetch)) {

		if (mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, synchronizing, prefetch)) {

			wrprot = true;

			pte_access &= ~ACC_WRITE_MASK;

			spte &= ~(PT_WRITABLE_MASK | shadow_mmu_writable_mask);

arch/x86/kvm/mmu/spte.h

+1 −1
Original line number Diff line number Diff line
@@ -499,7 +499,7 @@ bool spte_has_volatile_bits(u64 spte); 
bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,

	       const struct kvm_memory_slot *slot,

	       unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn,

	       u64 old_spte, bool prefetch, bool can_unsync,

	       u64 old_spte, bool prefetch, bool synchronizing,

	       bool host_writable, u64 *new_spte);

u64 make_huge_page_split_spte(struct kvm *kvm, u64 huge_spte,

		      	      union kvm_mmu_page_role role, int index);