From fc56578682aaeff18773c3c65ea6cdaa1bb44d92 Mon Sep 17 00:00:00 2001
From: Gregory Lirent <opensource@lirent.ru>
Date: Sat, 3 Aug 2024 21:05:54 +0300
Subject: [PATCH] Fix rdtsc patch

---
 patches/9999-rdtsc-hook.patch | 64 +++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 patches/9999-rdtsc-hook.patch

diff --git a/patches/9999-rdtsc-hook.patch b/patches/9999-rdtsc-hook.patch
new file mode 100644
index 0000000..a2313c6
--- /dev/null
+++ b/patches/9999-rdtsc-hook.patch
@@ -0,0 +1,64 @@
+diff -Naur --no-dereference a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
+--- a/arch/x86/kvm/vmx/vmx.c     2024-07-01 21:03:34.000000000 +0300
++++ b/arch/x86/kvm/vmx/vmx.c     2024-07-01 20:24:05.000000000 +0300
+@@ -2714,6 +2714,7 @@
+ 	vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
+ 	vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
+ 	vmcs_conf->cpu_based_2nd_exec_ctrl = _cpu_based_2nd_exec_control;
+ 	vmcs_conf->cpu_based_3rd_exec_ctrl = _cpu_based_3rd_exec_control;
+-	vmcs_conf->vmexit_ctrl         = _vmexit_control;
++	vmcs_conf->vmexit_ctrl         = _vmexit_control | CPU_BASED_RDTSC_EXITING;
+ 	vmcs_conf->vmentry_ctrl        = _vmentry_control;
+ 	vmcs_conf->misc	= misc_msr;
+diff -Naur --no-dereference a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
+--- a/arch/x86/kvm/vmx/vmx.c     2024-07-01 21:03:34.000000000 +0300
++++ b/arch/x86/kvm/vmx/vmx.c     2024-07-01 20:24:05.000000000 +0300
+@@ -6128,6 +6128,7 @@
+ 	[EXIT_REASON_ENCLS]		      = handle_encls,
+ 	[EXIT_REASON_BUS_LOCK]                = handle_bus_lock_vmexit,
+ 	[EXIT_REASON_NOTIFY]		      = handle_notify,
++	[EXIT_REASON_RDTSC]                        = handle_rdtsc,
+ };
+
+ static const int kvm_vmx_max_exit_handlers =
+
+diff -Naur --no-dereference a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
+--- a/arch/x86/kvm/vmx/vmx.c     2024-07-01 21:03:34.000000000 +0300
++++ b/arch/x86/kvm/vmx/vmx.c     2024-07-01 20:24:05.000000000 +0300
+@@ -6070,6 +6070,36 @@
+ 	return 1;
+ }
+
++static int handle_rdtsc(struct kvm_vcpu *vcpu)
++{
++	static u32 _ = 1;
++	static u64 rdtsc_cur  = 0;
++	static u64 rdtsc_prev = 0;
++	u64 _rdtsc = rdtsc();
++
++	printk_once("[HookEntry] fake rdtsc vmx function is working\n");
++
++	if (_)
++   {
++		rdtsc_cur = _rdtsc;
++		_ = 0;
++	}
++	if (rdtsc_prev != 0 && _rdtsc > rdtsc_prev)
++	{
++		rdtsc_cur += (_rdtsc - rdtsc_prev) / 16;
++	}
++
++	if (rdtsc_cur > _rdtsc)
++	{
++		rdtsc_cur = _rdtsc;
++	}
++
++	rdtsc_prev = rdtsc_cur;
++	vcpu->arch.regs[VCPU_REGS_RAX] = rdtsc_cur & -1u;
++	vcpu->arch.regs[VCPU_REGS_RDX] = (rdtsc_cur >> 32) & -1u;
++	return skip_emulated_instruction(vcpu);
++}
++
+ /*
+  * The exit handlers return 1 if the exit was handled fully and guest execution
+  * may resume.  Otherwise they set the kvm_run parameter to indicate what needs