minimal KVM abstraction + real mode guest example

1 files changed, 248 insertions, 0 deletions

diff --git a/src/kvm_sys.rs b/src/kvm_sys.rs
new file mode 100644
index 0000000..8d5c85b
--- /dev/null
+++ b/src/kvm_sys.rs
@@ -0,0 +1,248 @@
+#![allow(non_snake_case)]
+#![allow(non_camel_case_types)]
+#![allow(dead_code)]
+
+// Generated by `build.rs`.
+include!(concat!(env!("OUT_DIR"), "/kvm_constants.rs"));
+
+use std::fmt;
+
+#[repr(C)]
+#[derive(Default, Debug)]
+pub struct Rflags(pub u64);
+
+#[repr(C)]
+#[derive(Default, Debug)]
+pub struct kvm_regs {
+    pub rax: u64,
+    pub rbx: u64,
+    pub rcx: u64,
+    pub rdx: u64,
+    pub rsi: u64,
+    pub rdi: u64,
+    pub rsp: u64,
+    pub rbp: u64,
+    pub r8: u64,
+    pub r9: u64,
+    pub r10: u64,
+    pub r11: u64,
+    pub r12: u64,
+    pub r13: u64,
+    pub r14: u64,
+    pub r15: u64,
+    pub rip: u64,
+    pub rflags: Rflags,
+}
+
+#[repr(C)]
+#[derive(Default, Debug)]
+pub struct kvm_segment {
+    pub base: u64,
+    pub limit: u32,
+    pub selector: u16,
+    pub type_: u8,
+    pub present: u8,
+    pub dpl: u8,
+    pub db: u8,
+    pub s: u8,
+    pub l: u8,
+    pub g: u8,
+    pub avl: u8,
+    unusable: u8,
+    _padding: u8,
+}
+
+#[repr(C)]
+#[derive(Default, Debug)]
+pub struct kvm_dtable {
+    pub base: u64,
+    pub limit: u16,
+    _padding: [u16; 3],
+}
+
+#[repr(C)]
+#[derive(Default, Debug)]
+pub struct kvm_sregs {
+    pub cs: kvm_segment,
+    pub ds: kvm_segment,
+    pub es: kvm_segment,
+    pub fs: kvm_segment,
+    pub gs: kvm_segment,
+    pub ss: kvm_segment,
+    pub tr: kvm_segment,
+    pub ldt: kvm_segment,
+    pub gdt: kvm_dtable,
+    pub idt: kvm_dtable,
+    pub cr0: u64,
+    cr2: u64,
+    pub cr3: u64,
+    pub cr4: u64,
+    pub cr8: u64,
+    pub effer: u64,
+    pub apic_base: u64,
+    pub interrupt_bitmap: [u64; 4],
+}
+
+#[repr(C)]
+#[derive(Default, Debug)]
+pub(crate) struct kvm_userspace_memory_region {
+    pub slot: u32,
+    pub flags: u32,
+    pub guest_phys_addr: u64,
+    pub memory_size: u64,
+    pub userspace_addr: u64,
+}
+
+#[repr(C)]
+pub(crate) struct kvm_run {
+    request_interrupt_window: u8,
+    immediate_exit: u8,
+    padding1: [u8; 6],
+    pub exit_reason: u32,
+    ready_for_interrupt_injection: u8,
+    if_flag: u8,
+    flags: u16,
+    cr8: u64,
+    apic_base: u64,
+    pub inner: kvm_run_union,
+    kvm_valid_regs: u64,
+    kvm_dirty_regs: u64,
+    s: kvm_run_union_s,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct kvm_run_io {
+    pub direction: u8,
+    pub size: u8,
+    pub port: u16,
+    pub count: u32,
+    pub data_offset: u64,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct kvm_run_mmio {
+    pub phys_addr: u64,
+    pub data: [u8; 8],
+    pub len: u32,
+    pub is_write: u8,
+}
+
+// Only add the union fields used here.
+#[repr(C)]
+pub(crate) union kvm_run_union {
+    pub io: kvm_run_io,
+    pub mmio: kvm_run_mmio,
+    padding: [u8; 256],
+}
+
+// Only add the union fields used here.
+#[repr(C)]
+union kvm_run_union_s {
+    padding: [u8; 2048],
+}
+
+// {{{ Display : Rflags
+
+impl fmt::Display for Rflags {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let IF = || (self.0 >> 9) & 0b1;
+        let IOPL = || (self.0 >> 12) & 0b11;
+        let AC = || (self.0 >> 19) & 0b1;
+        write!(f, "AC({}) IOPL({}) IF({})", AC(), IOPL(), IF())
+    }
+}
+
+// }}}
+// {{{ Display : kvm_regs
+
+impl fmt::Display for kvm_regs {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "rax: {:#018x} rbx: {:#018x} rcx: {:#018x} rdx: {:#018x}\n\
+             rsi: {:#018x} rdi: {:#018x}\n\
+             r8 : {:#018x} r9 : {:#018x} r10: {:#018x} r11: {:#018x}\n\
+             r12: {:#018x} r13: {:#018x} r14: {:#018x} r15: {:#018x}\n\
+             rsp: {:#018x} rbp: {:#018x}\n\
+             rip: {:#018x} rflags: {:#018x} [{}]",
+            self.rax,
+            self.rbx,
+            self.rcx,
+            self.rdx,
+            self.rsi,
+            self.rdi,
+            self.r8,
+            self.r9,
+            self.r10,
+            self.r11,
+            self.r12,
+            self.r13,
+            self.r14,
+            self.r15,
+            self.rsp,
+            self.rbp,
+            self.rip,
+            self.rflags.0,
+            self.rflags
+        )
+    }
+}
+
+// }}}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::mem;
+
+    #[test]
+    fn check_kvm_regs() {
+        assert_eq!(mem::size_of::<kvm_regs>(), TEST_KVM_REGS_SIZE);
+        assert_eq!(mem::align_of::<kvm_regs>(), TEST_KVM_REGS_ALIGN);
+    }
+
+    #[test]
+    fn check_kvm_segment() {
+        assert_eq!(mem::size_of::<kvm_segment>(), TEST_KVM_SEGMENT_SIZE);
+        assert_eq!(mem::align_of::<kvm_segment>(), TEST_KVM_SEGMENT_ALIGN);
+    }
+
+    #[test]
+    fn check_kvm_dtable() {
+        assert_eq!(mem::size_of::<kvm_dtable>(), TEST_KVM_DTABLE_SIZE);
+        assert_eq!(mem::align_of::<kvm_dtable>(), TEST_KVM_DTABLE_ALIGN);
+    }
+
+    #[test]
+    fn check_kvm_sregs() {
+        assert_eq!(mem::size_of::<kvm_sregs>(), TEST_KVM_SREGS_SIZE);
+        assert_eq!(mem::align_of::<kvm_sregs>(), TEST_KVM_SREGS_ALIGN);
+        assert_eq!(
+            mem::size_of_val(&kvm_sregs::default().interrupt_bitmap),
+            TEST_KVM_SREGS_INTERRTUP_BITMAP_SIZE
+        );
+    }
+
+    #[test]
+    fn check_kvm_userspace_memory_region() {
+        assert_eq!(
+            mem::size_of::<kvm_userspace_memory_region>(),
+            TEST_KVM_USERSPACE_MEMORY_REGION_SIZE
+        );
+        assert_eq!(
+            mem::align_of::<kvm_userspace_memory_region>(),
+            TEST_KVM_USERSPACE_MEMORY_REGION_ALIGN
+        );
+    }
+
+    #[test]
+    fn check_kvm_run() {
+        assert_eq!(mem::size_of::<kvm_run>(), TEST_KVM_RUN_SIZE);
+        assert_eq!(mem::align_of::<kvm_run>(), TEST_KVM_RUN_ALIGN);
+        assert_eq!(mem::size_of::<kvm_run_io>(), TEST_KVM_RUN_IO_SIZE);
+        assert_eq!(mem::size_of::<kvm_run_mmio>(), TEST_KVM_RUN_MMIO_SIZE);
+        assert_eq!(mem::size_of::<kvm_run_union_s>(), TEST_KVM_RUN_UNION_S_SIZE);
+    }
+}