linux-kernel - [RFC PATCH v2 51/69] KVM: x86/mmu: Allow per-VM override of the TDP max page level

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <e2521b4c48c582260454764e84a057a2da99ac3c.1625186503.git.isaku.yamahata@intel.com>
Date:   Fri,  2 Jul 2021 15:04:57 -0700
From:   isaku.yamahata@...el.com
To:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H . Peter Anvin" <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, erdemaktas@...gle.com,
        Connor Kuehl <ckuehl@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     isaku.yamahata@...el.com, isaku.yamahata@...il.com,
        Sean Christopherson <sean.j.christopherson@...el.com>
Subject: [RFC PATCH v2 51/69] KVM: x86/mmu: Allow per-VM override of the TDP max page level

From: Sean Christopherson <sean.j.christopherson@...el.com>

TODO: This is tentative patch.  Support large page and delete this patch.

Allow TDX to effectively disable large pages, as SEPT will initially
support only 4k pages.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@...el.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/mmu/mmu.c          | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9631b985ebdc..a47e17892258 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -989,6 +989,7 @@ struct kvm_arch {
 	unsigned long n_requested_mmu_pages;
 	unsigned long n_max_mmu_pages;
 	unsigned int indirect_shadow_pages;
+	int tdp_max_page_level;
 	u8 mmu_valid_gen;
 	struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES];
 	struct list_head active_mmu_pages;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 82db62753acb..4ee6d7803f18 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4084,7 +4084,7 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 	kvm_pfn_t pfn;
 	int max_level;
 
-	for (max_level = KVM_MAX_HUGEPAGE_LEVEL;
+	for (max_level = vcpu->kvm->arch.tdp_max_page_level;
 	     max_level > PG_LEVEL_4K;
 	     max_level--) {
 		int page_num = KVM_PAGES_PER_HPAGE(max_level);
@@ -5802,6 +5802,8 @@ void kvm_mmu_init_vm(struct kvm *kvm)
 	node->track_write = kvm_mmu_pte_write;
 	node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot;
 	kvm_page_track_register_notifier(kvm, node);
+
+	kvm->arch.tdp_max_page_level = KVM_MAX_HUGEPAGE_LEVEL;
 }
 
 void kvm_mmu_uninit_vm(struct kvm *kvm)
-- 
2.25.1