by Avi Kivity

[permalink] [raw]

Subject: Re: [PATCH 0/7] KVM: Kernel-based Virtual Machine (v2)

Avi Kivity wrote:
> I'll also reply to this mail with a sample userspace so people can see
> how it works.

Attached is the source for a small library (libkvm.a) and a small test
harness (kvmctl) plus a few tests (test/*). The only test which will
work now is sieve.flat (I haven't used the tests since we got a real OS
booting, and had to scrub it up a bit). The tests are currently only
for x86_64.

The library is also used in our qemu patch (not included). I'll post
that later on.

Basically, the library adds function wrappers around the ioctl()s, and
converts exit reasons to callbacks, so the user need not code that large
switch.

To try it, compile it, modprobe kvm, and

./kvmctl test/bootstrap test/sieve.flat

"bootstrap" is a bit of code to take the machine to 32-bit nonpaged
mode. sieve.flat will go into long mode and tell you some uninteresting
facts about prime numbers.

--
error compiling committee.c: too many arguments to function

Attachments:

kvm-sample-userspace.tar.gz (8.09 kB)

2006-10-23 15:38:54

Code that wants to use struct desc_struct cannot do so on i386 because
desc.h contains other code that will only compile on x86_64.

So extract the structure definitions into a asm-x86_64/desc_defs.h.

Signed-off-by: Avi Kivity <[email protected]>

include/asm-x86_64/desc.h | 53 +------------------------------
include/asm-x86_64/desc_defs.h | 69 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 70 insertions(+), 52 deletions(-)

diff --git a/include/asm-x86_64/desc.h b/include/asm-x86_64/desc.h
index eb7723a..913d6ac 100644
--- a/include/asm-x86_64/desc.h
+++ b/include/asm-x86_64/desc.h
@@ -9,64 +9,13 @@ #ifndef __ASSEMBLY__

#include <linux/string.h>
#include <linux/smp.h>
+#include <asm/desc_defs.h>

#include <asm/segment.h>
#include <asm/mmu.h>

-// 8 byte segment descriptor
-struct desc_struct {
- u16 limit0;
- u16 base0;
- unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1;
- unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8;
-} __attribute__((packed));
-
-struct n_desc_struct {
- unsigned int a,b;
-};
-
extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];

-enum {
- GATE_INTERRUPT = 0xE,
- GATE_TRAP = 0xF,
- GATE_CALL = 0xC,
-};
-
-// 16byte gate
-struct gate_struct {
- u16 offset_low;
- u16 segment;
- unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
- u16 offset_middle;
- u32 offset_high;
- u32 zero1;
-} __attribute__((packed));
-
-#define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF)
-#define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF)
-#define PTR_HIGH(x) ((unsigned long)(x) >> 32)
-
-enum {
- DESC_TSS = 0x9,
- DESC_LDT = 0x2,
-};
-
-// LDT or TSS descriptor in the GDT. 16 bytes.
-struct ldttss_desc {
- u16 limit0;
- u16 base0;
- unsigned base1 : 8, type : 5, dpl : 2, p : 1;
- unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
- u32 base3;
- u32 zero1;
-} __attribute__((packed));
-
-struct desc_ptr {
- unsigned short size;
- unsigned long address;
-} __attribute__((packed)) ;
-
#define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8))
#define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8))
#define clear_LDT() asm volatile("lldt %w0"::"r" (0))
diff --git a/include/asm-x86_64/desc_defs.h b/include/asm-x86_64/desc_defs.h
new file mode 100644
index 0000000..7408266
--- /dev/null
+++ b/include/asm-x86_64/desc_defs.h
@@ -0,0 +1,69 @@
+/* Written 2000 by Andi Kleen */
+#ifndef __ARCH_DESC_DEFS_H
+#define __ARCH_DESC_DEFS_H
+
+/*
+ * Segment descriptor structure definitions, usable from both x86_64 and i386
+ * archs.
+ */
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+// 8 byte segment descriptor
+struct desc_struct {
+ u16 limit0;
+ u16 base0;
+ unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1;
+ unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8;
+} __attribute__((packed));
+
+struct n_desc_struct {
+ unsigned int a,b;
+};
+
+enum {
+ GATE_INTERRUPT = 0xE,
+ GATE_TRAP = 0xF,
+ GATE_CALL = 0xC,
+};
+
+// 16byte gate
+struct gate_struct {
+ u16 offset_low;
+ u16 segment;
+ unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
+ u16 offset_middle;
+ u32 offset_high;
+ u32 zero1;
+} __attribute__((packed));
+
+#define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF)
+#define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF)
+#define PTR_HIGH(x) ((unsigned long)(x) >> 32)
+
+enum {
+ DESC_TSS = 0x9,
+ DESC_LDT = 0x2,
+};
+
+// LDT or TSS descriptor in the GDT. 16 bytes.
+struct ldttss_desc {
+ u16 limit0;
+ u16 base0;
+ unsigned base1 : 8, type : 5, dpl : 2, p : 1;
+ unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
+ u32 base3;
+ u32 zero1;
+} __attribute__((packed));
+
+struct desc_ptr {
+ unsigned short size;
+ unsigned long address;
+} __attribute__((packed)) ;
+
+
+#endif /* !__ASSEMBLY__ */
+
+#endif

--
error compiling committee.c: too many arguments to function

2006-10-24 14:11:04

by Andi Kleen

[permalink] [raw]

Subject: Re: [PATCH] x86: Extract segment descriptor definitions for use outside of x86_64

On Tuesday 24 October 2006 06:43, Avi Kivity wrote:
> Code that wants to use struct desc_struct cannot do so on i386 because
> desc.h contains other code that will only compile on x86_64.
>
> So extract the structure definitions into a asm-x86_64/desc_defs.h.
Added thanks
-Andi