From: Sean Christopherson <sean.j.christopherson@intel.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Adam Borowski <kilobyte@angband.pl>,
David Hildenbrand <david@redhat.com>,
Dan Williams <dan.j.williams@intel.com>
Subject: [PATCH 2/2] KVM: x86/mmu: Add helper to consolidate huge page promotion
Date: Wed, 6 Nov 2019 09:07:27 -0800 [thread overview]
Message-ID: <20191106170727.14457-3-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20191106170727.14457-1-sean.j.christopherson@intel.com>
Add a helper, kvm_is_hugepage_allowed(), to consolidate nearly identical
code between transparent_hugepage_adjust() and
kvm_mmu_zap_collapsible_spte().
Note, this effectively adds a superfluous is_error_noslot_pfn() check in
kvm_mmu_zap_collapsible_spte(), but the overhead added is essentially a
single uop on modern hardware and taking the hit allows all the PFN
related checks to be encapsulated in kvm_is_hugepage_allowed().
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/mmu.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index bf82b1f2e834..8565653fce22 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3292,6 +3292,13 @@ static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)
return -EFAULT;
}
+static bool kvm_is_hugepage_allowed(kvm_pfn_t pfn)
+{
+ return !is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) &&
+ !kvm_is_zone_device_pfn(pfn) &&
+ PageTransCompoundMap(pfn_to_page(pfn));
+}
+
static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
gfn_t gfn, kvm_pfn_t *pfnp,
int *levelp)
@@ -3305,9 +3312,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
* 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 &&
- PageTransCompoundMap(pfn_to_page(pfn)) &&
+ if (level == PT_PAGE_TABLE_LEVEL && kvm_is_hugepage_allowed(pfn) &&
!mmu_gfn_lpage_is_disallowed(vcpu, gfn, PT_DIRECTORY_LEVEL)) {
unsigned long mask;
/*
@@ -5914,9 +5919,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
* the guest, and the guest page table is using 4K page size
* mapping if the indirect sp has level = 1.
*/
- if (sp->role.direct && !kvm_is_reserved_pfn(pfn) &&
- !kvm_is_zone_device_pfn(pfn) &&
- PageTransCompoundMap(pfn_to_page(pfn))) {
+ if (sp->role.direct && kvm_is_hugepage_allowed(pfn)) {
pte_list_remove(rmap_head, sptep);
if (kvm_available_flush_tlb_with_range())
--
2.24.0
next prev parent reply other threads:[~2019-11-06 17:07 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-06 17:07 [PATCH 0/2] KVM: MMU: Fix a refcount bug with ZONE_DEVICE pages Sean Christopherson
2019-11-06 17:07 ` [PATCH 1/2] KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved Sean Christopherson
2019-11-06 17:14 ` Paolo Bonzini
2019-11-06 17:46 ` Sean Christopherson
2019-11-06 18:04 ` Dan Williams
2019-11-06 20:26 ` Sean Christopherson
2019-11-06 20:34 ` Dan Williams
2019-11-06 21:09 ` Paolo Bonzini
2019-11-06 21:30 ` Sean Christopherson
2019-11-06 23:20 ` Dan Williams
2019-11-06 23:39 ` Sean Christopherson
2019-11-07 0:01 ` Dan Williams
2019-11-07 5:48 ` Dan Williams
2019-11-07 11:12 ` Paolo Bonzini
2019-11-07 15:36 ` Dan Williams
2019-11-07 15:58 ` Sean Christopherson
2019-11-09 1:43 ` Sean Christopherson
2019-11-09 2:00 ` Dan Williams
2019-11-11 18:27 ` Sean Christopherson
2019-11-11 19:15 ` Paolo Bonzini
2019-11-12 0:51 ` Dan Williams
2019-11-12 10:19 ` Paolo Bonzini
2019-11-12 16:57 ` Sean Christopherson
2019-11-06 17:07 ` Sean Christopherson [this message]
2019-11-06 17:22 ` [PATCH 2/2] KVM: x86/mmu: Add helper to consolidate huge page promotion Paolo Bonzini
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