linux-kernel - [RFC 10/19] KVM: x86/mmu: Remove need for a vcpu from mmu_try_to_unsync

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Message-Id: <20211110223010.1392399-11-bgardon@google.com>
Date:   Wed, 10 Nov 2021 14:30:01 -0800
From:   Ben Gardon <bgardon@...gle.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>, Peter Xu <peterx@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Peter Shier <pshier@...gle.com>,
        David Matlack <dmatlack@...gle.com>,
        Mingwei Zhang <mizhang@...gle.com>,
        Yulei Zhang <yulei.kernel@...il.com>,
        Wanpeng Li <kernellwp@...il.com>,
        Xiao Guangrong <xiaoguangrong.eric@...il.com>,
        Kai Huang <kai.huang@...el.com>,
        Keqian Zhu <zhukeqian1@...wei.com>,
        David Hildenbrand <david@...hat.com>,
        Ben Gardon <bgardon@...gle.com>
Subject: [RFC 10/19] KVM: x86/mmu: Remove need for a vcpu from mmu_try_to_unsync_pages

The vCPU argument to mmu_try_to_unsync_pages is now only used to get a
pointer to the associated struct kvm, so pass in the kvm pointer from
the beginning to remove the need for a vCPU when calling the function.


Signed-off-by: Ben Gardon <bgardon@...gle.com>
---
 arch/x86/kvm/mmu/mmu.c          | 16 ++++++++--------
 arch/x86/kvm/mmu/mmu_internal.h |  2 +-
 arch/x86/kvm/mmu/spte.c         |  2 +-
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 7d0da79668c0..1e890509b93f 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2561,10 +2561,10 @@ static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
 	return r;
 }
 
-static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	trace_kvm_mmu_unsync_page(sp);
-	++vcpu->kvm->stat.mmu_unsync;
+	++kvm->stat.mmu_unsync;
 	sp->unsync = 1;
 
 	kvm_mmu_mark_parents_unsync(sp);
@@ -2576,7 +2576,7 @@ static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
  * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must
  * be write-protected.
  */
-int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
+int mmu_try_to_unsync_pages(struct kvm *kvm, struct kvm_memory_slot *slot,
 			    gfn_t gfn, bool can_unsync, bool prefetch)
 {
 	struct kvm_mmu_page *sp;
@@ -2587,7 +2587,7 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 	 * track machinery is used to write-protect upper-level shadow pages,
 	 * i.e. this guards the role.level == 4K assertion below!
 	 */
-	if (kvm_slot_page_track_is_active(vcpu->kvm, slot, gfn, KVM_PAGE_TRACK_WRITE))
+	if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE))
 		return -EPERM;
 
 	/*
@@ -2596,7 +2596,7 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 	 * 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_indirect_valid_sp(vcpu->kvm, sp, gfn) {
+	for_each_gfn_indirect_valid_sp(kvm, sp, gfn) {
 		if (!can_unsync)
 			return -EPERM;
 
@@ -2615,7 +2615,7 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 		 */
 		if (!locked) {
 			locked = true;
-			spin_lock(&vcpu->kvm->arch.mmu_unsync_pages_lock);
+			spin_lock(&kvm->arch.mmu_unsync_pages_lock);
 
 			/*
 			 * Recheck after taking the spinlock, a different vCPU
@@ -2630,10 +2630,10 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 		}
 
 		WARN_ON(sp->role.level != PG_LEVEL_4K);
-		kvm_unsync_page(vcpu, sp);
+		kvm_unsync_page(kvm, sp);
 	}
 	if (locked)
-		spin_unlock(&vcpu->kvm->arch.mmu_unsync_pages_lock);
+		spin_unlock(&kvm->arch.mmu_unsync_pages_lock);
 
 	/*
 	 * We need to ensure that the marking of unsync pages is visible
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 52c6527b1a06..1073d10cce91 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -118,7 +118,7 @@ static inline bool kvm_vcpu_ad_need_write_protect(struct kvm_vcpu *vcpu)
 	       kvm_x86_ops.cpu_dirty_log_size;
 }
 
-int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
+int mmu_try_to_unsync_pages(struct kvm *kvm, struct kvm_memory_slot *slot,
 			    gfn_t gfn, bool can_unsync, bool prefetch);
 
 void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index 75c666d3e7f1..b7271daa06c5 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -160,7 +160,7 @@ 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, slot, gfn, can_unsync, prefetch)) {
+		if (mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, can_unsync, prefetch)) {
 			pgprintk("%s: found shadow page for %llx, marking ro\n",
 				 __func__, gfn);
 			wrprot = true;
-- 
2.34.0.rc0.344.g81b53c2807-goog