vcpu: nfc: minor refactor

Signed-off-by: smallkirby <[email protected]>
smallkirby · Nov 3, 2024 · f06b5f4 · f06b5f4
1 parent 54b6c04
commit f06b5f4
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Showing 3 changed files with 22 additions and 23 deletions.
diff --git a/ymir/arch/x86/arch.zig b/ymir/arch/x86/arch.zig
@@ -61,21 +61,17 @@ pub inline fn enableCpuid() void {
     }
 }
 
+/// Get CPU Vendr ID string.
+/// Note that the string is not null-terminated.
 pub fn getCpuVendorId() [12]u8 {
     var ret: [12]u8 = undefined;
-    const regs = cpuid.Leaf.maximum_input.query(null);
+    const regs = cpuid.Leaf.query(.maximum_input, null);
 
-    for (0..4) |i| {
-        const b: usize = (regs.ebx >> @truncate(i * 8));
-        ret[0 + i] = @as(u8, @truncate(b));
-    }
-    for (0..4) |i| {
-        const b: usize = (regs.edx >> @truncate(i * 8));
-        ret[4 + i] = @as(u8, @truncate(b));
-    }
-    for (0..4) |i| {
-        const b: usize = (regs.ecx >> @truncate(i * 8));
-        ret[8 + i] = @as(u8, @truncate(b));
+    for ([_]u32{ regs.ebx, regs.edx, regs.ecx }, 0..) |reg, i| {
+        for (0..4) |j| {
+            const b: usize = (reg >> @truncate(j * 8));
+            ret[i * 4 + j] = @as(u8, @truncate(b));
+        }
     }
     return ret;
 }
@@ -93,6 +89,7 @@ pub fn isVmxSupported() bool {
         // Enable VMX outside SMX.
         if (msr_fctl.lock) @panic("IA32_FEATURE_CONTROL is locked while VMX outside SMX is disabled");
         msr_fctl.vmx_outside_smx = true;
+        msr_fctl.lock = true;
         am.writeMsrFeatureControl(msr_fctl);
     }
     msr_fctl = am.readMsrFeatureControl();

diff --git a/ymir/arch/x86/asm.zig b/ymir/arch/x86/asm.zig
@@ -273,7 +273,7 @@ pub fn writeMsrFeatureControl(value: MsrFeatureControl) void {
 }
 
 pub fn readMsrVmxBasic() MsrVmxBasic {
-    const val = readMsr(Msr.vmx_basic);
+    const val = readMsr(.vmx_basic);
     return @bitCast(val);
 }
 

diff --git a/ymir/arch/x86/vmx/vcpu.zig b/ymir/arch/x86/vmx/vcpu.zig
@@ -434,9 +434,8 @@ fn adjustControlRegisters() void {
 }
 
 /// Read VMCS revision identifier.
-fn getVmcsRevisionId() u31 {
-    const vmx_basic = am.readMsrVmxBasic();
-    return vmx_basic.vmcs_revision_id;
+inline fn getVmcsRevisionId() u31 {
+    return am.readMsrVmxBasic().vmcs_revision_id;
 }
 
 /// Puts the logical processor in VMX operation with no VMCS loaded.
@@ -784,9 +783,10 @@ const VmxonRegion = packed struct {
     zero: u1 = 0,
 
     /// Allocate VMXON region.
-    pub fn new(page_allocator: Allocator) VmxError!*align(4096) VmxonRegion {
-        const page = page_allocator.alloc(u8, 4096) catch return VmxError.OutOfMemory;
-        if (page.len != 4096 or @intFromPtr(page.ptr) % 4096 != 0) {
+    pub fn new(page_allocator: Allocator) VmxError!*align(mem.page_size) VmxonRegion {
+        const size = am.readMsrVmxBasic().vmxon_region_size;
+        const page = page_allocator.alloc(u8, size) catch return VmxError.OutOfMemory;
+        if (@intFromPtr(page.ptr) % mem.page_size != 0) {
             return error.OutOfMemory;
         }
         @memset(page, 0);
@@ -795,7 +795,7 @@ const VmxonRegion = packed struct {
 
     pub fn deinit(self: *VmxonRegion, page_allocator: Allocator) void {
         const ptr: [*]u8 = @ptrCast(self);
-        page_allocator.free(ptr[0..4096]);
+        page_allocator.free(ptr[0..mem.page_size]);
     }
 };
 
@@ -813,17 +813,19 @@ const VmcsRegion = packed struct {
 
     /// Allocate a VMCS region.
     pub fn new(page_allocator: Allocator) VmxError!*align(4096) VmcsRegion {
-        const page = try page_allocator.alloc(u8, 4096);
-        if (page.len != 4096 or @intFromPtr(page.ptr) % 4096 != 0) {
+        const size = am.readMsrVmxBasic().vmxon_region_size;
+        const page = try page_allocator.alloc(u8, size);
+        if (@intFromPtr(page.ptr) % mem.page_size != 0) {
             return error.OutOfMemory;
         }
         @memset(page, 0);
         return @alignCast(@ptrCast(page.ptr));
     }
 
     pub fn deinit(self: *VmcsRegion, page_allocator: Allocator) void {
+        const size = am.readMsrVmxBasic().vmxon_region_size;
         const ptr: [*]u8 = @ptrCast(self);
-        page_allocator.free(ptr[0..4096]);
+        page_allocator.free(ptr[0..size]);
     }
 };