linux-kernel - [PATCH 06/16] KVM: MMU: change page_fault_handle_page_track() arguments to kvm_page

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Message-Id: <20210807134936.3083984-7-pbonzini@redhat.com>
Date:   Sat,  7 Aug 2021 09:49:26 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     isaku.yamahata@...el.com, David Matlack <dmatlack@...gle.com>,
        seanjc@...gle.com, peterx@...hat.com
Subject: [PATCH 06/16] KVM: MMU: change page_fault_handle_page_track() arguments to kvm_page_fault

Add fields to struct kvm_page_fault corresponding to the arguments
of page_fault_handle_page_track().  The fields are initialized in the
callers, and page_fault_handle_page_track() receives a struct
kvm_page_fault instead of having to extract the arguments out of it.

Suggested-by: Isaku Yamahata <isaku.yamahata@...el.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/mmu.h             |  3 +++
 arch/x86/kvm/mmu/mmu.c         | 18 +++++++++---------
 arch/x86/kvm/mmu/paging_tmpl.h |  7 ++++---
 3 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 158263847bef..c3d404155ceb 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -132,6 +132,9 @@ struct kvm_page_fault {
 
 	/* Input to FNAME(fetch), __direct_map and kvm_tdp_mmu_map.  */
 	u8 max_level;
+
+	/* Shifted addr, or result of guest page table walk if addr is a gva.  */
+	gfn_t gfn;
 };
 
 int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e93ee0ebe5ff..3af49678d4f8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3788,20 +3788,19 @@ static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 }
 
 static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu,
-					 u32 error_code, gfn_t gfn)
+					 struct kvm_page_fault *fault)
 {
-	if (unlikely(error_code & PFERR_RSVD_MASK))
+	if (unlikely(fault->rsvd))
 		return false;
 
-	if (!(error_code & PFERR_PRESENT_MASK) ||
-	      !(error_code & PFERR_WRITE_MASK))
+	if (!fault->present || !fault->write)
 		return false;
 
 	/*
 	 * guest is writing the page which is write tracked which can
 	 * not be fixed by page fault handler.
 	 */
-	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+	if (kvm_page_track_is_active(vcpu, fault->gfn, KVM_PAGE_TRACK_WRITE))
 		return true;
 
 	return false;
@@ -3885,13 +3884,13 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
 	bool map_writable;
 
-	gfn_t gfn = gpa >> PAGE_SHIFT;
 	unsigned long mmu_seq;
 	kvm_pfn_t pfn;
 	hva_t hva;
 	int r;
 
-	if (page_fault_handle_page_track(vcpu, error_code, gfn))
+	fault->gfn = gpa >> PAGE_SHIFT;
+	if (page_fault_handle_page_track(vcpu, fault))
 		return RET_PF_EMULATE;
 
 	r = fast_page_fault(vcpu, gpa, error_code);
@@ -3905,11 +3904,12 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
 	smp_rmb();
 
-	if (try_async_pf(vcpu, fault->prefault, gfn, gpa, &pfn, &hva,
+	if (try_async_pf(vcpu, fault->prefault, fault->gfn, gpa, &pfn, &hva,
 			 fault->write, &map_writable))
 		return RET_PF_RETRY;
 
-	if (handle_abnormal_pfn(vcpu, fault->is_tdp ? 0 : gpa, gfn, pfn, ACC_ALL, &r))
+	if (handle_abnormal_pfn(vcpu, fault->is_tdp ? 0 : gpa,
+	                        fault->gfn, pfn, ACC_ALL, &r))
 		return r;
 
 	r = RET_PF_RETRY;
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 5352323646b0..2ef219bf1745 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -858,7 +858,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 		return RET_PF_RETRY;
 	}
 
-	if (page_fault_handle_page_track(vcpu, error_code, walker.gfn)) {
+	fault->gfn = walker.gfn;
+	if (page_fault_handle_page_track(vcpu, fault)) {
 		shadow_page_table_clear_flood(vcpu, addr);
 		return RET_PF_EMULATE;
 	}
@@ -880,11 +881,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
 	smp_rmb();
 
-	if (try_async_pf(vcpu, fault->prefault, walker.gfn, addr, &pfn, &hva,
+	if (try_async_pf(vcpu, fault->prefault, fault->gfn, addr, &pfn, &hva,
 			 fault->write, &map_writable))
 		return RET_PF_RETRY;
 
-	if (handle_abnormal_pfn(vcpu, addr, walker.gfn, pfn, walker.pte_access, &r))
+	if (handle_abnormal_pfn(vcpu, addr, fault->gfn, pfn, walker.pte_access, &r))
 		return r;
 
 	/*
-- 
2.27.0