enable AMD-V

nel_os_bootloader/run-qemu.sh

@@ -14,5 +14,6 @@ qemu-system-x86_64 -enable-kvm \
 	-cdrom nel_os.iso \
 	-boot d \
 	-cpu host \
+	-enable-kvm \
 	-smp 1 \
 	-s

nel_os_kernel/src/vmm/mod.rs

@@ -8,13 +8,16 @@ use crate::{
 pub mod x86_64;
 
 pub trait VCpu {
+    fn is_supported() -> bool
+    where
+        Self: Sized;
     fn run(&mut self);
 }
 
 pub fn get_vcpu() -> Box<dyn VCpu> {
-    if platform::is_amd() {
+    if platform::is_amd() && AMDVCpu::is_supported() {
         Box::new(AMDVCpu::new())
-    } else if platform::is_intel() {
+    } else if platform::is_intel() && IntelVCpu::is_supported() {
         Box::new(IntelVCpu::new())
     } else {
         panic!("Unsupported CPU architecture");

nel_os_kernel/src/vmm/x86_64/amd/mod.rs

@@ -1,9 +1,18 @@
-use crate::{info, vmm::VCpu};
+use raw_cpuid::cpuid;
+
+use crate::{
+    info,
+    vmm::{x86_64::common, VCpu},
+};
 
 pub struct AMDVCpu;
 
 impl AMDVCpu {
     pub fn new() -> Self {
+        let mut efer = common::read_msr(0xc000_0080);
+        efer |= 1 << 12;
+        common::write_msr(0xc000_0080, efer);
+
         AMDVCpu
     }
 }
@@ -12,4 +21,21 @@ impl VCpu for AMDVCpu {
     fn run(&mut self) {
         info!("VCpu on AMD");
     }
+
+    fn is_supported() -> bool
+    where
+        Self: Sized,
+    {
+        if cpuid!(0x8000_0001).ecx & (1 << 2) == 0 {
+            info!("SVM not supported by CPU");
+            return false;
+        }
+
+        if common::read_msr(0xc001_0114) & (1 << 4) != 0 {
+            info!("SVM disabled by BIOS");
+            return false;
+        }
+
+        true
+    }
 }

nel_os_kernel/src/vmm/x86_64/common/mod.rs

@@ -0,0 +1,31 @@
+use core::arch::asm;
+
+pub fn read_msr(msr: u32) -> u64 {
+    let mut low: u32;
+    let mut high: u32;
+
+    unsafe {
+        asm!(
+            "rdmsr",
+            out("eax") low,
+            out("edx") high,
+            in("ecx") msr,
+        );
+    }
+
+    ((high as u64) << 32) | (low as u64)
+}
+
+pub fn write_msr(msr: u32, value: u64) {
+    let low = value as u32;
+    let high = (value >> 32) as u32;
+
+    unsafe {
+        asm!(
+            "wrmsr",
+            in("eax") low,
+            in("edx") high,
+            in("ecx") msr,
+        );
+    }
+}

nel_os_kernel/src/vmm/x86_64/intel/mod.rs

@@ -12,4 +12,11 @@ impl VCpu for IntelVCpu {
     fn run(&mut self) {
         info!("VCpu on Intel");
     }
+
+    fn is_supported() -> bool
+    where
+        Self: Sized,
+    {
+        true
+    }
 }