linux-kernel - [RFC PATCH v6 044/104] KVM: x86/mmu: Focibly use TDP MMU for TDX

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]

Date:   Thu,  5 May 2022 11:14:38 -0700
From:   isaku.yamahata@...el.com
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     isaku.yamahata@...el.com, isaku.yamahata@...il.com,
        Paolo Bonzini <pbonzini@...hat.com>, erdemaktas@...gle.com,
        Sean Christopherson <seanjc@...gle.com>,
        Sagi Shahar <sagis@...gle.com>
Subject: [RFC PATCH v6 044/104] KVM: x86/mmu: Focibly use TDP MMU for TDX

From: Isaku Yamahata <isaku.yamahata@...el.com>

In this patch series, TDX supports only TDP MMU and doesn't support legacy
MMU.  Forcibly use TDP MMU for TDX irrelevant of kernel parameter to
disable TDP MMU.

Signed-off-by: Isaku Yamahata <isaku.yamahata@...el.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index f8c1824d85a5..b8850a0ceb15 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -18,8 +18,13 @@ int kvm_mmu_init_tdp_mmu(struct kvm *kvm)
 {
 	struct workqueue_struct *wq;
 
-	if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled))
-		return 0;
+	/*
+	 *  Because TDX supports only TDP MMU, forcibly use TDP MMU in the case
+	 *  of TDX.
+	 */
+	if (kvm->arch.vm_type != KVM_X86_TDX_VM &&
+		(!tdp_enabled || !READ_ONCE(tdp_mmu_enabled)))
+		return false;
 
 	wq = alloc_workqueue("kvm", WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 0);
 	if (!wq)
-- 
2.25.1