minimal KVM abstraction + real mode guest example

2 files changed, 89 insertions, 0 deletions

diff --git a/sysdeps/Makefile b/sysdeps/Makefile
new file mode 100644
index 0000000..092047e
--- /dev/null
+++ b/sysdeps/Makefile
@@ -0,0 +1,10 @@
+OUT ?= /dev/stdout
+
+gen: kvm
+	./kvm > $(OUT)
+
+kvm: kvm.c
+	$(CC) $(CFLAGS) -Wpedantic -Wall -Wextra -Werror -o $@ $^
+
+clean:
+	$(RM) kvm
diff --git a/sysdeps/kvm.c b/sysdeps/kvm.c
new file mode 100644
index 0000000..1665349
--- /dev/null
+++ b/sysdeps/kvm.c
@@ -0,0 +1,79 @@
+#include <linux/kvm.h>
+
+#include <stdio.h>
+#include <stdalign.h> // alignof operator
+#include <stddef.h>   // offsetof operator
+
+int main() {
+    /* Global constants */
+
+    printf("pub(crate) const KVM_API_VERSION : i32 = 0x%x;\n", KVM_API_VERSION);
+
+    /* ioctl's for /dev/kvm */
+
+    // param: none
+    // ret  : constant KVM_API_VERSION (=12)
+    printf("pub(crate) const KVM_GET_API_VERSION : u64 = 0x%x;\n", KVM_GET_API_VERSION);
+    // param: machine type identifier (most cases just 0)
+    // ret  : VM fd
+    printf("pub(crate) const KVM_CREATE_VM : u64 = 0x%x;\n", KVM_CREATE_VM);
+    // param: none
+    // ret  : size of vcpu mmap region in bytes
+    printf("pub(crate) const KVM_GET_VCPU_MMAP_SIZE : u64 = 0x%x;\n", KVM_GET_VCPU_MMAP_SIZE);
+
+    /* ioctl's for VM fd */
+
+    // param: vpcu id
+    // ret  : VCPU fd
+    printf("pub(crate) const KVM_CREATE_VCPU : u64 = 0x%x;\n", KVM_CREATE_VCPU);
+    // param: struct kvm_userspace_memory_region
+    // ret  : 0 success, -1 error
+    printf("pub(crate) const KVM_SET_USER_MEMORY_REGION : u64 = 0x%lx;\n", KVM_SET_USER_MEMORY_REGION);
+
+    /* ioctl's for VCPU fd */
+
+    // param: none
+    // ret  : 0 success, -1 error
+    printf("pub(crate) const KVM_RUN : u64 = 0x%x;\n", KVM_RUN);
+    // param: struct kvm_regs
+    // ret  : 0 success, -1 error
+    printf("pub(crate) const KVM_GET_REGS : u64 = 0x%lx;\n", KVM_GET_REGS);
+    // param: struct kvm_regs
+    // ret  : 0 success, -1 error
+    printf("pub(crate) const KVM_SET_REGS : u64 = 0x%lx;\n", KVM_SET_REGS);
+    // param: struct kvm_sregs
+    // ret  : 0 success, -1 error
+    printf("pub(crate) const KVM_GET_SREGS : u64 = 0x%lx;\n", KVM_GET_SREGS);
+    // param: struct kvm_sregs
+    // ret  : 0 success, -1 error
+    printf("pub(crate) const KVM_SET_SREGS : u64 = 0x%lx;\n", KVM_SET_SREGS);
+
+    /* struct kvm_run constants */
+
+    printf("pub(crate) const KVM_EXIT_HLT : u64 = 0x%x;\n", KVM_EXIT_HLT);
+    printf("pub(crate) const KVM_EXIT_IO : u64 = 0x%x;\n", KVM_EXIT_IO);
+    printf("pub(crate) const KVM_EXIT_IO_IN : u64 = 0x%x;\n", KVM_EXIT_IO_IN);
+    printf("pub(crate) const KVM_EXIT_IO_OUT : u64 = 0x%x;\n", KVM_EXIT_IO_OUT);
+    printf("pub(crate) const KVM_EXIT_MMIO : u64 = 0x%x;\n", KVM_EXIT_MMIO);
+
+    /* Testing constants */
+
+    printf("#[cfg(test)] const TEST_KVM_REGS_SIZE : usize = %ld;\n", sizeof(struct kvm_regs));
+    printf("#[cfg(test)] const TEST_KVM_REGS_ALIGN : usize = %ld;\n", alignof(struct kvm_regs));
+    printf("#[cfg(test)] const TEST_KVM_SREGS_SIZE : usize = %ld;\n", sizeof(struct kvm_sregs));
+    printf("#[cfg(test)] const TEST_KVM_SREGS_ALIGN : usize = %ld;\n", alignof(struct kvm_sregs));
+    printf("#[cfg(test)] const TEST_KVM_SREGS_INTERRTUP_BITMAP_SIZE : usize = %ld;\n", sizeof(((struct kvm_sregs*)0)->interrupt_bitmap));
+    printf("#[cfg(test)] const TEST_KVM_SEGMENT_SIZE : usize = %ld;\n", sizeof(struct kvm_segment));
+    printf("#[cfg(test)] const TEST_KVM_SEGMENT_ALIGN : usize = %ld;\n", alignof(struct kvm_segment));
+    printf("#[cfg(test)] const TEST_KVM_DTABLE_SIZE : usize = %ld;\n", sizeof(struct kvm_dtable));
+    printf("#[cfg(test)] const TEST_KVM_DTABLE_ALIGN : usize = %ld;\n", alignof(struct kvm_dtable));
+    printf("#[cfg(test)] const TEST_KVM_USERSPACE_MEMORY_REGION_SIZE : usize = %ld;\n", sizeof(struct kvm_userspace_memory_region));
+    printf("#[cfg(test)] const TEST_KVM_USERSPACE_MEMORY_REGION_ALIGN : usize = %ld;\n", alignof(struct kvm_userspace_memory_region));
+    printf("#[cfg(test)] const TEST_KVM_RUN_SIZE : usize = %ld;\n", sizeof(struct kvm_run));
+    printf("#[cfg(test)] const TEST_KVM_RUN_ALIGN : usize = %ld;\n", alignof(struct kvm_run));
+    printf("#[cfg(test)] const TEST_KVM_RUN_IO_SIZE : usize = %ld;\n", sizeof(((struct kvm_run*)0)->io));
+    printf("#[cfg(test)] const TEST_KVM_RUN_MMIO_SIZE : usize = %ld;\n", sizeof(((struct kvm_run*)0)->mmio));
+    printf("#[cfg(test)] const TEST_KVM_RUN_UNION_S_SIZE : usize = %ld;\n", sizeof(((struct kvm_run*)0)->s));
+
+    return 0;
+}