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From: Yan Zhao <yan.y.zhao@intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: pbonzini@redhat.com, seanjc@google.com, chao.gao@intel.com,
	kai.huang@intel.com, robert.hoo.linux@gmail.com,
	yuan.yao@linux.intel.com, Yan Zhao <yan.y.zhao@intel.com>
Subject: [PATCH v4 02/12] KVM: x86/mmu: Use KVM honors guest MTRRs helper in kvm_tdp_page_fault()
Date: Fri, 14 Jul 2023 14:50:43 +0800	[thread overview]
Message-ID: <20230714065043.20258-1-yan.y.zhao@intel.com> (raw)
In-Reply-To: <20230714064656.20147-1-yan.y.zhao@intel.com>

Let kvm_tdp_page_fault() use helper function kvm_mmu_honors_guest_mtrrs()
to decide if it needs to consult guest MTRR to check GFN range consistency.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
 arch/x86/kvm/mmu/mmu.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index b4f89f015c37..7f52bbe013b3 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4536,16 +4536,9 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 	/*
 	 * If the guest's MTRRs may be used to compute the "real" memtype,
 	 * restrict the mapping level to ensure KVM uses a consistent memtype
-	 * across the entire mapping.  If the host MTRRs are ignored by TDP
-	 * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA
-	 * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype
-	 * from the guest's MTRRs so that guest accesses to memory that is
-	 * DMA'd aren't cached against the guest's wishes.
-	 *
-	 * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs,
-	 * e.g. KVM will force UC memtype for host MMIO.
+	 * across the entire mapping.
 	 */
-	if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) {
+	if (kvm_mmu_honors_guest_mtrrs(vcpu->kvm)) {
 		for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) {
 			int page_num = KVM_PAGES_PER_HPAGE(fault->max_level);
 			gfn_t base = gfn_round_for_level(fault->gfn,
-- 
2.17.1


  parent reply	other threads:[~2023-07-14  7:18 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-14  6:46 [PATCH v4 00/12] KVM: x86/mmu: refine memtype related mmu zap Yan Zhao
2023-07-14  6:50 ` [PATCH v4 01/12] KVM: x86/mmu: helpers to return if KVM honors guest MTRRs Yan Zhao
2023-10-07  7:00   ` Like Xu
2023-10-09 19:52     ` Sean Christopherson
2023-10-09 21:27       ` Sean Christopherson
2023-10-09 21:36         ` Sean Christopherson
2023-10-10  3:46         ` Yan Zhao
2023-10-11  0:08           ` Sean Christopherson
2023-10-11  1:47             ` Yan Zhao
2023-07-14  6:50 ` Yan Zhao [this message]
2023-07-14  6:51 ` [PATCH v4 03/12] KVM: x86/mmu: Use KVM honors guest MTRRs helper when CR0.CD toggles Yan Zhao
2023-07-14  6:51 ` [PATCH v4 04/12] KVM: x86/mmu: Use KVM honors guest MTRRs helper when update mtrr Yan Zhao
2023-07-14  6:52 ` [PATCH v4 05/12] KVM: x86/mmu: zap KVM TDP when noncoherent DMA assignment starts/stops Yan Zhao
2023-07-14  6:52 ` [PATCH v4 06/12] KVM: x86/mmu: move TDP zaps from guest MTRRs update to CR0.CD toggling Yan Zhao
2023-07-14  6:53 ` [PATCH v4 07/12] KVM: VMX: drop IPAT in memtype when CD=1 for KVM_X86_QUIRK_CD_NW_CLEARED Yan Zhao
2023-08-25 21:43   ` Sean Christopherson
2023-09-04  7:41     ` Yan Zhao
2023-07-14  6:53 ` [PATCH v4 08/12] KVM: x86: centralize code to get CD=1 memtype when guest MTRRs are honored Yan Zhao
2023-08-25 21:46   ` Sean Christopherson
2023-09-04  7:46     ` Yan Zhao
2023-07-14  6:54 ` [PATCH v4 09/12] KVM: x86/mmu: serialize vCPUs to zap gfn " Yan Zhao
2023-08-25 22:47   ` Sean Christopherson
2023-09-04  8:24     ` Yan Zhao
2023-07-14  6:55 ` [PATCH v4 10/12] KVM: x86/mmu: fine-grained gfn zap " Yan Zhao
2023-08-25 23:13   ` Sean Christopherson
2023-09-04  8:37     ` Yan Zhao
2023-07-14  6:56 ` [PATCH v4 11/12] KVM: x86/mmu: split a single gfn zap range " Yan Zhao
2023-08-25 23:15   ` Sean Christopherson
2023-09-04  8:39     ` Yan Zhao
2023-07-14  6:56 ` [PATCH v4 12/12] KVM: x86/mmu: convert kvm_zap_gfn_range() to use shared mmu_lock in TDP MMU Yan Zhao
2023-08-25 21:34   ` Sean Christopherson
2023-09-04  7:31     ` Yan Zhao
2023-09-05 22:31       ` Sean Christopherson
2023-09-06  0:50         ` Yan Zhao
2023-08-25 23:17 ` [PATCH v4 00/12] KVM: x86/mmu: refine memtype related mmu zap Sean Christopherson
2023-09-04  8:48   ` Yan Zhao
2023-10-05  1:29 ` Sean Christopherson
2023-10-05  2:19   ` Huang, Kai
2023-10-05  2:28     ` Sean Christopherson
2023-10-06  0:50       ` Sean Christopherson

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