cap.rs - source

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     }
 }

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@@ -132,6 +133,7 @@
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use std::fmt;
 
 use crate::kvm_sys::{kvm_dtable, kvm_regs, kvm_segment, kvm_sregs};
@@ -146,7 +148,7 @@
              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} rfl: {:#018x} O({}) D({}) I({}) S({}) Z({}) P({}) C({})",
+             rip: {:#018x} rfl: {:#018x} O({}) D({}) I({}) T({}) S({}) Z({}) P({}) C({})",
             self.rax,
             self.rbx,
             self.rcx,
@@ -168,6 +170,7 @@
             rflags_of(self.rflags),
             rflags_df(self.rflags),
             rflags_if(self.rflags),
+            rflags_tf(self.rflags),
             rflags_sf(self.rflags),
             rflags_zf(self.rflags),
             rflags_pf(self.rflags),
@@ -262,5 +265,5 @@
     }
 }

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     }
 }

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//! Definitions of the system header [`<linux/kvm.h>`][kvm-h].
 //!
 //! [kvm-h]: https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/kvm.h
@@ -293,6 +367,32 @@
     pub userspace_addr: u64,
 }
 
+#[cfg(target_arch = "x86_64")]
+#[repr(C)]
+#[derive(Default, Debug)]
+pub struct kvm_debugregs {
+    pub db: [u64; 4],
+    pub dr6: u64,
+    pub dr7: u64,
+    pub flags: u64,
+    pub reserved: [u64; 9],
+}
+
+#[repr(C)]
+#[derive(Default, Debug)]
+pub(crate) struct kvm_guest_debug {
+    pub control: u32,
+    pad: u32,
+    pub arch: kvm_guest_debug_arch,
+}
+
+#[cfg(target_arch = "x86_64")]
+#[repr(C)]
+#[derive(Default, Debug)]
+pub(crate) struct kvm_guest_debug_arch {
+    pub debugreg: [u64; 8],
+}
+
 #[repr(C)]
 pub(crate) struct kvm_run {
     request_interrupt_window: u8,
@@ -329,11 +429,23 @@
     pub is_write: u8,
 }
 
+#[cfg(target_arch = "x86_64")]
+#[repr(C)]
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct kvm_run_debug {
+    pub exception: u32,
+    pad: u32,
+    pub pc: u64,
+    pub dr6: u64,
+    pub dr7: u64,
+}
+
 // 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,
+    pub debug: kvm_run_debug,
     padding: [u8; 256],
 }
 
@@ -396,7 +508,42 @@
         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);
     }
+
+    #[cfg(target_arch = "x86_64")]
+    #[test]
+    fn check_kvm_run_x86() {
+        assert_eq!(mem::size_of::<kvm_run_debug>(), TEST_KVM_RUN_DEBUG_SIZE);
+    }
+
+    #[cfg(target_arch = "x86_64")]
+    #[test]
+    fn check_kvm_debugregs() {
+        assert_eq!(mem::size_of::<kvm_debugregs>(), TEST_KVM_DEBUGREGS_SIZE);
+        assert_eq!(mem::align_of::<kvm_debugregs>(), TEST_KVM_DEBUGREGS_ALIGN);
+    }
+
+    #[test]
+    fn check_kvm_guest_dbg() {
+        assert_eq!(mem::size_of::<kvm_guest_debug>(), TEST_KVM_GUEST_DEBUG_SIZE);
+        assert_eq!(
+            mem::align_of::<kvm_guest_debug>(),
+            TEST_KVM_GUEST_DEBUG_ALIGN
+        );
+    }
+
+    #[cfg(target_arch = "x86_64")]
+    #[test]
+    fn check_kvm_guest_dbg_arch() {
+        assert_eq!(
+            mem::size_of::<kvm_guest_debug_arch>(),
+            TEST_KVM_GUEST_DEBUG_ARCH_SIZE
+        );
+        assert_eq!(
+            mem::align_of::<kvm_guest_debug_arch>(),
+            TEST_KVM_GUEST_DEBUG_ARCH_ALIGN
+        );
+    }
 }

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@@ -336,5 +337,5 @@
     }
 }

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//! VCPU system ioctls.
 
 use std::fs;
@@ -159,6 +226,7 @@
     IoOut(u16, &'cpu [u8]),
     MmioRead(u64, &'cpu mut [u8]),
     MmioWrite(u64, &'cpu [u8]),
+    Debug(u64),
 }
 
 /// Wrapper for VCPU ioctls.
@@ -227,6 +295,65 @@
         .map(|_| ())
     }
 
+    /// Get the debug registers with the [`KVM_GET_DEBUGREGS`][kvm-get-debugregs] ioctl in form of
+    /// [`kvm_debugregs`](crate::kvm_sys::kvm_debugregs).
+    ///
+    /// [kvm-get-debugregs]:
+    /// https://www.kernel.org/doc/html/latest/virt/kvm/api.html#kvm-get-debugregs
+    #[cfg(target_arch = "x86_64")]
+    pub fn get_debugregs(&self) -> io::Result<kvm_sys::kvm_debugregs> {
+        let mut dregs = kvm_sys::kvm_debugregs::default();
+        ioctl(
+            &self.vcpu,
+            kvm_sys::KVM_GET_DEBUGREGS,
+            &mut dregs as *mut _ as u64,
+        )?;
+        Ok(dregs)
+    }
+
+    /// Set the debug registers with the [`KVM_SET_DEBUGREGS`][kvm-set-debugregs] ioctl in form of
+    /// [`kvm_debugregs`](crate::kvm_sys::kvm_debugregs).
+    ///
+    /// [kvm-set-debugregs]:
+    /// https://www.kernel.org/doc/html/latest/virt/kvm/api.html#kvm-set-debugregs
+    #[cfg(target_arch = "x86_64")]
+    pub fn set_debugregs(&self, dregs: kvm_sys::kvm_debugregs) -> io::Result<()> {
+        ioctl(
+            &self.vcpu,
+            kvm_sys::KVM_SET_DEBUGREGS,
+            &dregs as *const _ as u64,
+        )
+        .map(|_| ())
+    }
+
+    /// Enable or disable guest single steppig (debug) with the
+    /// [`KVM_GUESTDBG_ENABLE`][kvm-guest-debug] ioctl.
+    ///
+    /// [kvm-guest-debug]: https://www.kernel.org/doc/html/latest/virt/kvm/api.html#kvm-set-guest-debug
+    #[cfg(target_arch = "x86_64")]
+    pub fn set_single_step(&self, enable: bool) -> io::Result<()> {
+        let mut dbg = kvm_sys::kvm_guest_debug::default();
+
+        if enable {
+            // Enable guest debugging and single stepping.
+            dbg.control = kvm_sys::KVM_GUESTDBG_ENABLE | kvm_sys::KVM_GUESTDBG_SINGLESTEP;
+        }
+
+        // Initialize debug registers based on current VCPUs debug register values.
+        let dregs = self.get_debugregs()?;
+        dbg.arch.debugreg[0..4].copy_from_slice(&dregs.db);
+        // DR4-DR5 are reserved.
+        dbg.arch.debugreg[6] = dregs.dr6;
+        dbg.arch.debugreg[7] = dregs.dr7;
+
+        ioctl(
+            &self.vcpu,
+            kvm_sys::KVM_SET_GUEST_DEBUG,
+            &dbg as *const _ as u64,
+        )
+        .map(|_| ())
+    }
+
     /// Run the guest VCPU with the [`KVM_RUN`][kvm-run] ioctl until it exits with one of the exit
     /// reasons described in [`KvmExit`](crate::vcpu::KvmExit).
     ///
@@ -269,6 +396,12 @@
                     _ => unreachable!(),
                 }
             }
+            kvm_sys::KVM_EXIT_DEBUG => {
+                // Safe to use union `debug` field, as Kernel instructed us to.
+                let debug = unsafe { kvm_run.inner.debug };
+
+                Ok(KvmExit::Debug(debug.pc))
+            }
             r @ _ => {
                 todo!("KVM_EXIT_... (exit_reason={}) not implemented!", r)
             }
@@ -276,5 +409,5 @@
     }
 }

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     }
 }

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//! `x86_64` flags and bitfields.
 
 pub use x86_64::*;
@@ -180,6 +184,8 @@
     pub const RFLAGS_ZF: u64 = 1 << 6;
     /// Sign flag.
     pub const RFLAGS_SF: u64 = 1 << 7;
+    /// Trap flag.
+    pub const RFLAGS_TF: u64 = 1 << 8;
     /// Sign flag.
     pub const RFLAGS_IF: u64 = 1 << 9;
     /// Direction flag.
@@ -196,6 +202,7 @@
     pub const fn rflags_af(r: u64) -> u64   { (r & RFLAGS_AF)   >> 4 }
     pub const fn rflags_zf(r: u64) -> u64   { (r & RFLAGS_ZF)   >> 6 }
     pub const fn rflags_sf(r: u64) -> u64   { (r & RFLAGS_SF)   >> 7 }
+    pub const fn rflags_tf(r: u64) -> u64   { (r & RFLAGS_TF)   >> 8 }
     pub const fn rflags_if(r: u64) -> u64   { (r & RFLAGS_IF)   >> 9 }
     pub const fn rflags_df(r: u64) -> u64   { (r & RFLAGS_DF)   >> 10 }
     pub const fn rflags_of(r: u64) -> u64   { (r & RFLAGS_OF)   >> 11 }
@@ -319,8 +326,8 @@
     /// Page region read/write.
     ///
     /// If set, region reference by paging entry is writeable.
-    pub const PAGE_RENTRY_RW: u64 = 1 << 1;
+    pub const PAGE_ENTRY_RW: u64 = 1 << 1;
 }