CSR: hstatus: add register module

This register is present when the hypervisor extension is supported. It
provides the hypervisor status.

Signed-off-by: Clément Léger <cleger@rivosinc.com>

src/register/hstatus.rs

@@ -0,0 +1,142 @@
+//! hstatus register
+
+use crate::register::misa;
+use bit_field::BitField;
+
+/// Hypervisor Status Register
+#[derive(Clone, Copy, Debug)]
+pub struct Hstatus {
+    bits: usize,
+}
+
+/// Supervisor Previous Virtual Privilege Mode
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum SPVP {
+    Supervisor = 1,
+    User = 0,
+}
+
+impl Hstatus {
+    /// Virtual Supervisor Big-endian Enable
+    #[inline]
+    pub fn vsbe(&self) -> bool {
+        self.bits.get_bit(5)
+    }
+
+    /// Guest Virtual Address
+    #[inline]
+    pub fn gva(&self) -> bool {
+        self.bits.get_bit(6)
+    }
+
+    /// Supervisor Previous Virtualization mode
+    #[inline]
+    pub fn spv(&self) -> bool {
+        self.bits.get_bit(7)
+    }
+
+    /// Supervisor Previous Virtual Privilege Mode
+    #[inline]
+    pub fn spvp(&self) -> SPVP {
+        match self.bits.get_bit(8) {
+            true => SPVP::Supervisor,
+            false => SPVP::User,
+        }
+    }
+
+    /// Hypervisor in U-mode
+    #[inline]
+    pub fn hu(&self) -> bool {
+        self.bits.get_bit(7)
+    }
+
+    /// Virtual Guest External Interrupt Number
+    #[inline]
+    pub fn vgein(&self) -> usize {
+        self.bits.get_bits(12..17)
+    }
+
+    /// Virtual Mode Trap Virtual Memory
+    #[inline]
+    pub fn vtvm(&self) -> bool {
+        self.bits.get_bit(20)
+    }
+
+    /// Virtual Mode Timeout Wait
+    #[inline]
+    pub fn vtw(&self) -> bool {
+        self.bits.get_bit(21)
+    }
+
+    /// Virtual Mode Trap SRET
+    #[inline]
+    pub fn vtsr(&self) -> bool {
+        self.bits.get_bit(22)
+    }
+
+    /// VS-Mode XLEN
+    #[inline]
+    #[cfg(target_pointer_width = "64")]
+    pub fn vsxl(&self) -> misa::MXL {
+        match self.bits.get_bits(32..33) {
+            1 => misa::MXL::XLEN32,
+            2 => misa::MXL::XLEN64,
+            3 => misa::MXL::XLEN128,
+            _ => unreachable!(),
+        }
+    }
+}
+
+read_csr_as!(Hstatus, 0x600);
+write_csr!(0x600);
+set!(0x600);
+clear!(0x600);
+
+set_clear_csr!(
+    /// Virtual Supervisor Big-endian Enable
+    , set_vsbe, clear_vsbe, 1 << 5);
+set_clear_csr!(
+    /// Guest Virtual Address
+    , set_gva, clear_gva, 1 << 6);
+set_clear_csr!(
+    /// Supervisor Previous Virtualization mode
+    , set_spv, clear_spv, 1 << 7);
+
+/// Supervisor Previous Virtual Privilege Mode
+#[inline]
+/// Virtual Guest External Interrupt Number
+pub unsafe fn set_spvp(spvp: SPVP) {
+    match spvp {
+        SPVP::Supervisor => _set(1 << 8),
+        SPVP::User => _clear(1 << 8),
+    }
+}
+
+set_clear_csr!(
+    /// Hypervisor in U-mode
+    , set_hu, clear_hu, 1 << 9);
+
+#[inline]
+pub unsafe fn set_vgein(vgein: usize) {
+    let mut value = _read();
+    value.set_bits(12..17, vgein);
+    _write(value);
+}
+
+set_clear_csr!(
+    /// Virtual Mode Trap Virtual Memory
+    , set_vtvm, clear_vtvm, 1 << 20);
+set_clear_csr!(
+    /// Virtual Mode Timeout Wait
+    , set_vtw, clear_vtw, 1 << 21);
+set_clear_csr!(
+    /// Virtual Mode Trap SRET
+    , set_vtsr, clear_vtsr, 1 << 22);
+
+#[inline]
+#[cfg(target_pointer_width = "64")]
+pub unsafe fn set_vsxl(vsxl: misa::MXL) {
+    let mut value = _read();
+    value.set_bits(32..33, vsxl as usize);
+    _write(value);
+}

src/register/mod.rs

@@ -66,6 +66,9 @@ pub mod sireg;
 pub mod siselect;
 pub mod stopei;
 
+// Hypervisor Trap Setup
+pub mod hstatus;
+
 // Machine Information Registers
 pub mod marchid;
 pub mod mhartid;