linux-kernel - [PATCH 4.9 21/31] KVM: x86: remove now unneeded hugepage gfn adjustment

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Message-Id: <20191115062017.892821068@linuxfoundation.org>
Date:   Fri, 15 Nov 2019 14:20:50 +0800
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Ben Hutchings <ben@...adent.org.uk>
Subject: [PATCH 4.9 21/31] KVM: x86: remove now unneeded hugepage gfn adjustment

From: Paolo Bonzini <pbonzini@...hat.com>

commit d679b32611c0102ce33b9e1a4e4b94854ed1812a upstream.

After the previous patch, the low bits of the gfn are masked in
both FNAME(fetch) and __direct_map, so we do not need to clear them
in transparent_hugepage_adjust.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/x86/kvm/mmu.c         |    9 +++------
 arch/x86/kvm/paging_tmpl.h |    2 +-
 2 files changed, 4 insertions(+), 7 deletions(-)

--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2824,11 +2824,10 @@ static int kvm_handle_bad_page(struct kv
 }
 
 static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
-					gfn_t *gfnp, kvm_pfn_t *pfnp,
+					gfn_t gfn, kvm_pfn_t *pfnp,
 					int *levelp)
 {
 	kvm_pfn_t pfn = *pfnp;
-	gfn_t gfn = *gfnp;
 	int level = *levelp;
 
 	/*
@@ -2855,8 +2854,6 @@ static void transparent_hugepage_adjust(
 		mask = KVM_PAGES_PER_HPAGE(level) - 1;
 		VM_BUG_ON((gfn & mask) != (pfn & mask));
 		if (pfn & mask) {
-			gfn &= ~mask;
-			*gfnp = gfn;
 			kvm_release_pfn_clean(pfn);
 			pfn &= ~mask;
 			kvm_get_pfn(pfn);
@@ -3060,7 +3057,7 @@ static int nonpaging_map(struct kvm_vcpu
 		goto out_unlock;
 	make_mmu_pages_available(vcpu);
 	if (likely(!force_pt_level))
-		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
+		transparent_hugepage_adjust(vcpu, gfn, &pfn, &level);
 	r = __direct_map(vcpu, v, write, map_writable, level, pfn, prefault);
 out_unlock:
 	spin_unlock(&vcpu->kvm->mmu_lock);
@@ -3595,7 +3592,7 @@ static int tdp_page_fault(struct kvm_vcp
 		goto out_unlock;
 	make_mmu_pages_available(vcpu);
 	if (likely(!force_pt_level))
-		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
+		transparent_hugepage_adjust(vcpu, gfn, &pfn, &level);
 	r = __direct_map(vcpu, gpa, write, map_writable, level, pfn, prefault);
 out_unlock:
 	spin_unlock(&vcpu->kvm->mmu_lock);
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -806,7 +806,7 @@ static int FNAME(page_fault)(struct kvm_
 	kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);
 	make_mmu_pages_available(vcpu);
 	if (!force_pt_level)
-		transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
+		transparent_hugepage_adjust(vcpu, walker.gfn, &pfn, &level);
 	r = FNAME(fetch)(vcpu, addr, &walker, write_fault,
 			 level, pfn, map_writable, prefault);
 	kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);