From f715c49b313c0c6ef4ceebc168c644c2f0544c8f Mon Sep 17 00:00:00 2001
From: "iliya.saroukha" <iliya.saroukhanian@etu.hesge.ch>
Date: Mon, 9 Dec 2024 23:55:58 +0100
Subject: [PATCH] semi-feat: sometimes vmxon executes successfully, most of the
time the CF (Carry Flag) is set to 1..
---
proto/hypervisor.c | 36 ++++++++++++++++++------------------
1 file changed, 18 insertions(+), 18 deletions(-)
diff --git a/proto/hypervisor.c b/proto/hypervisor.c
index ee967a3..4eb4bcf 100644
--- a/proto/hypervisor.c
+++ b/proto/hypervisor.c
@@ -12,7 +12,6 @@
/*============== my includes ==============*/
#include "debug/debug.h"
-#include "linux/cleanup.h"
#include "msr/msr.h"
#include "region/vxmon_reg.h"
@@ -24,7 +23,7 @@
/* : clobbered registers list (optional)*/
/* );*/
-static struct vmxon_reg_t vmxon_region;
+static struct vmxon_region_t vmxon_region;
static void cr4_enable_vmx(void) {
unsigned long cr4;
@@ -50,10 +49,16 @@ static bool vmx_support_cpuid(void) {
static unsigned char vmxon(void *pa) {
unsigned char ret;
- __asm__ __volatile__("vmxon %[pa]; setna %[ret]"
- : [ret] "=rm"(ret)
- : [pa] "m"(vmxon_region.pa)
- : "cc", "memory");
+ __asm__ volatile("vmxon %[pa]; setna %[ret]"
+ : [ret] "=rm"(ret)
+ : [pa] "m"(pa)
+ : "cc", "memory");
+
+ unsigned long long rflags;
+
+ __asm__ volatile("pushfq; popq %0" : "=r"(rflags));
+ DEBUG_FMT("RFLAGS: 0x%llx\n", rflags);
+
return ret;
}
@@ -86,8 +91,6 @@ static int my_init(void) {
cr4_enable_vmx();
pr_info("Checking the necessary flags of the IA32_FEATURE_CONTROL_MSR\n");
- DEBUG_FMT("IA32_FEATURE_CONTROL = %llu\n",
- __rdmsr(IA32_FEATURE_CONTROL_MSR));
if (!ia32_feature_control_flags()) {
pr_err("The flags of the IA32_FEATURE_CONTROL MSR do not permit "
"virtualization\n");
@@ -97,30 +100,27 @@ static int my_init(void) {
pr_info("Executing VMXON with address = 0x%px as its operand\n",
vmxon_region.pa);
- /*__asm__ volatile("vmxon %0" ::"m"(vmxon_region.pa) : "memory");*/
-
- unsigned char vmxon_ret;
+ unsigned char vmxon_ret = 0;
if ((vmxon_ret = vmxon(vmxon_region.pa) != 0)) {
- pr_err("vmxon failed with return code %d\n", vmxon_ret);
+ kfree(vmxon_region.va);
+ pr_err("`vmxon` failed with return code %d\n", vmxon_ret);
return -1;
}
- DEBUG_FMT("vmxon ret = %d\n", vmxon_ret);
+ pr_info("`vmxon` was successfully executed!\n");
return 0;
}
static void my_exit(void) {
- printk(KERN_INFO "Executing VMXOFF\n");
-
+ pr_info("Executing VMXOFF\n");
__asm__ volatile("vmxoff");
- printk(KERN_INFO "Freeing memory of the VMXON region\n");
-
+ pr_info("Freeing memory of the VMXON region\n");
kfree(vmxon_region.va);
- printk(KERN_INFO "Hypervisor has exited\n");
+ pr_info("vmbr.ko has exited\n");
}
module_init(my_init);
--
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