linux-kernel - [PATCH v2 03/24] KVM: x86/mmu: Do not enable page track for TD guest

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: <20241112073515.22028-1-yan.y.zhao@intel.com>
Date: Tue, 12 Nov 2024 15:35:15 +0800
From: Yan Zhao <yan.y.zhao@...el.com>
To: pbonzini@...hat.com,
	seanjc@...gle.com,
	kvm@...r.kernel.org,
	dave.hansen@...ux.intel.com
Cc: rick.p.edgecombe@...el.com,
	kai.huang@...el.com,
	adrian.hunter@...el.com,
	reinette.chatre@...el.com,
	xiaoyao.li@...el.com,
	tony.lindgren@...el.com,
	binbin.wu@...ux.intel.com,
	dmatlack@...gle.com,
	isaku.yamahata@...el.com,
	isaku.yamahata@...il.com,
	nik.borisov@...e.com,
	linux-kernel@...r.kernel.org,
	x86@...nel.org
Subject: [PATCH v2 03/24] KVM: x86/mmu: Do not enable page track for TD guest

Fail kvm_page_track_write_tracking_enabled() if VM type is TDX to make the
external page track user fail in kvm_page_track_register_notifier() since
TDX does not support write protection and hence page track.

No need to fail KVM internal users of page track (i.e. for shadow page),
because TDX is always with EPT enabled and currently TDX module does not
emulate and send VMLAUNCH/VMRESUME VMExits to VMM.

Suggested-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Yan Zhao <yan.y.zhao@...el.com>
Reviewed-by: Binbin Wu <binbin.wu@...ux.intel.com>
Cc: Yuan Yao <yuan.yao@...ux.intel.com>
---
TDX MMU part 2 v2:
- Move the checking of VM type from kvm_page_track_write_tracking_enabled()
  to kvm_enable_external_write_tracking() to make
  kvm_page_track_register_notifier() fail. (Paolo)
- Updated patch msg (Yan)
- Added Paolo's Suggested-by tag since the patch is simple enough and the
  current implementation was suggested by Paolo (Yan)

v19:
- drop TDX: from the short log
- Added reviewed-by: BinBin
---
 arch/x86/kvm/mmu/page_track.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 561c331fd6ec..1b17b12393a8 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -172,6 +172,9 @@ static int kvm_enable_external_write_tracking(struct kvm *kvm)
 	struct kvm_memory_slot *slot;
 	int r = 0, i, bkt;
 
+	if (kvm->arch.vm_type == KVM_X86_TDX_VM)
+		return -EOPNOTSUPP;
+
 	mutex_lock(&kvm->slots_arch_lock);
 
 	/*
-- 
2.43.2