linux-kernel - [PATCH 14/18] KVM: TDX: Add methods to ignore accesses to TSC

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: <20241210004946.3718496-15-binbin.wu@linux.intel.com>
Date: Tue, 10 Dec 2024 08:49:40 +0800
From: Binbin Wu <binbin.wu@...ux.intel.com>
To: pbonzini@...hat.com,
	seanjc@...gle.com,
	kvm@...r.kernel.org
Cc: rick.p.edgecombe@...el.com,
	kai.huang@...el.com,
	adrian.hunter@...el.com,
	reinette.chatre@...el.com,
	xiaoyao.li@...el.com,
	tony.lindgren@...ux.intel.com,
	isaku.yamahata@...el.com,
	yan.y.zhao@...el.com,
	chao.gao@...el.com,
	linux-kernel@...r.kernel.org,
	binbin.wu@...ux.intel.com
Subject: [PATCH 14/18] KVM: TDX: Add methods to ignore accesses to TSC

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

TDX protects TDX guest TSC state from VMM.  Implement access methods to
ignore guest TSC.

Signed-off-by: Isaku Yamahata <isaku.yamahata@...el.com>
Signed-off-by: Binbin Wu <binbin.wu@...ux.intel.com>
---
TDX "the rest" breakout:
- Dropped KVM_BUG_ON() in vt_get_l2_tsc_offset(). (Rick)
---
 arch/x86/kvm/vmx/main.c | 44 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 40 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 4a9b176b8a36..81ca5acb9964 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -757,6 +757,42 @@ static int vt_set_identity_map_addr(struct kvm *kvm, u64 ident_addr)
 	return vmx_set_identity_map_addr(kvm, ident_addr);
 }
 
+static u64 vt_get_l2_tsc_offset(struct kvm_vcpu *vcpu)
+{
+	/* TDX doesn't support L2 guest at the moment. */
+	if (is_td_vcpu(vcpu))
+		return 0;
+
+	return vmx_get_l2_tsc_offset(vcpu);
+}
+
+static u64 vt_get_l2_tsc_multiplier(struct kvm_vcpu *vcpu)
+{
+	/* TDX doesn't support L2 guest at the moment. */
+	if (is_td_vcpu(vcpu))
+		return 0;
+
+	return vmx_get_l2_tsc_multiplier(vcpu);
+}
+
+static void vt_write_tsc_offset(struct kvm_vcpu *vcpu)
+{
+	/* In TDX, tsc offset can't be changed. */
+	if (is_td_vcpu(vcpu))
+		return;
+
+	vmx_write_tsc_offset(vcpu);
+}
+
+static void vt_write_tsc_multiplier(struct kvm_vcpu *vcpu)
+{
+	/* In TDX, tsc multiplier can't be changed. */
+	if (is_td_vcpu(vcpu))
+		return;
+
+	vmx_write_tsc_multiplier(vcpu);
+}
+
 #ifdef CONFIG_X86_64
 static int vt_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc,
 			      bool *expired)
@@ -914,10 +950,10 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 
 	.has_wbinvd_exit = cpu_has_vmx_wbinvd_exit,
 
-	.get_l2_tsc_offset = vmx_get_l2_tsc_offset,
-	.get_l2_tsc_multiplier = vmx_get_l2_tsc_multiplier,
-	.write_tsc_offset = vmx_write_tsc_offset,
-	.write_tsc_multiplier = vmx_write_tsc_multiplier,
+	.get_l2_tsc_offset = vt_get_l2_tsc_offset,
+	.get_l2_tsc_multiplier = vt_get_l2_tsc_multiplier,
+	.write_tsc_offset = vt_write_tsc_offset,
+	.write_tsc_multiplier = vt_write_tsc_multiplier,
 
 	.load_mmu_pgd = vt_load_mmu_pgd,
 
-- 
2.46.0