Commit Graph

43 Commits

Author SHA1 Message Date
Aurelien Jarno
4e62417bf3 KVM: x86 emulator: fix access registers for instructions with ModR/M byte and Mod = 3
The patch belows changes the access type to register from memory for
instructions that are declared as SrcMem or DstMem, but have a
ModR/M byte with Mod = 3.

It fixes (at least) the lmsw and smsw instructions on an AMD64 CPU,
which are needed for FreeBSD.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-22 12:03:29 +02:00
Sheng Yang
a012e65aee KVM: x86 emulator: implement 'movnti mem, reg'
Implement emulation of instruction:
    movnti m32/m64, r32/r64
    opcode: 0x0f 0xc3

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-22 12:03:29 +02:00
Laurent Vivier
ae6200baea KVM: x86 emulator: fix repne/repnz decoding
The repnz/repne instructions must set rep_prefix to 1 like rep/repe/repz.

This patch correct the disk probe problem met with OpenBSD.

This issue appears with commit e70669abd4
because before it, the decoding was done internally to kvm and after it
is done by x86_emulate.c (which doesn't do it correctly).

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-22 12:03:28 +02:00
Nitin A Kamble
1a52e05136 KVM: x86 emulator: fix merge screwup due to emulator split
This code has gone to wrong place in the file. Moving it back to
right location.

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-22 12:03:28 +02:00
Nitin A Kamble
535eabcf0e KVM: x86 emulator: popf
Implement emulation of instruction:
    popf
    opcode:  0x9d

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:29 +02:00
Nitin A Kamble
12fa272e31 KVM: x86 emulator: fix src, dst value initialization
Some operand fetches are less than the machine word size and can result in
stale bits if used together with operands of different sizes.

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:29 +02:00
Nitin A Kamble
26a3e983d1 KVM: x86 emulator: jmp abs
Implement emulation of instruction:
    jump absolute r/m
    opcode: 0xff /4

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:29 +02:00
Nitin A Kamble
7e0b54b149 KVM: x86 emulator: lea
Implement emulation of instruction
    lea r16/r32, m
    opcode:  0x8d:

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:29 +02:00
Nitin A Kamble
55bebde45e KVM: X86 emulator: jump conditional short
Implement emulation of more jump conditional instructions
    jcc shortrel
    opcodes: 0x70 - 0x7f

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:29 +02:00
Nitin A Kamble
bbe9abbdac KVM: x86 emulator: imlpement jump conditional relative
Implement emulation of instruction:
    jump conditional rel
    opcodes: 0x0f 0x80 - 0x0f 0x8f

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:28 +02:00
Nitin A Kamble
7de752482c KVM: x86 emulator: sort opcodes into ascending order
Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:28 +02:00
Nitin A Kamble
fd2a760865 KVM: x86 emulator: pushf
Implement emulation of instruction
	pushf
	opcode: 0x9c

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:28 +02:00
Nitin A Kamble
f6eed39135 KVM: x86 emulator: call near
Implement emulation of instruction
	opcode: 0xe8
	call (near)

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:28 +02:00
Nitin A Kamble
7d31691163 KVM: x86 emulator: push imm8
Implement the instruction

    	push imm8
    	opcode: 0x6a

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:28 +02:00
Christian Ehrhardt
cbdd1bea2a KVM: Rename kvm_arch_ops to kvm_x86_ops
This patch just renames the current (misnamed) _arch namings to _x86 to
ensure better readability when a real arch layer takes place.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:27 +02:00
Rusty Russell
b85b9ee925 KVM: Clean up unloved invlpg emulation
invlpg shouldn't fetch the "src" address, since it may not be valid,
however SVM's "solution" which neuters emulation of all group 7
instruction is horrible and breaks kvm-lite.  The simplest fix is to
put a special check in for invlpg.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:27 +02:00
Avi Kivity
d39dba54ce KVM: X86 emulator: fix 'push reg' writeback
Pointed out by Rusty Russell.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:24 +02:00
Nitin A Kamble
7e778161fb KVM: x86 emulator: implement 'push reg' (opcodes 0x50-0x57)
Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:24 +02:00
Nitin A Kamble
c53ce170a9 KVM: x86 emulator: Implement 'jmp rel short' instruction (opcode 0xeb)
Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:24 +02:00
Nitin A Kamble
098c937ba3 KVM: x86 emulator: implement 'jmp rel' instruction (opcode 0xe9)
Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:24 +02:00
Nitin A Kamble
19eb938e01 KVM: x86 emulator: implement 'and $imm, %{al|ax|eax}'
Implement emulation of instruction
    and al imm8 (opcode 0x24)
    and ax/eax imm16/imm32 (opcode 0x25)

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:23 +02:00
Laurent Vivier
3090dd7377 KVM: Clean up kvm_setup_pio()
Split kvm_setup_pio() into two functions, one to setup in/out pio
(kvm_emulate_pio()) and one to setup ins/outs pio (kvm_emulate_pio_string()).

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:23 +02:00
Laurent Vivier
e70669abd4 KVM: Cleanup string I/O instruction emulation
Both vmx and svm decode the I/O instructions, and both botch the job,
requiring the instruction prefixes to be fetched in order to completely
decode the instruction.

So, if we see a string I/O instruction, use the x86 emulator to decode it,
as it already has all the prefix decoding machinery.

This patch defines ins/outs opcodes in x86_emulate.c and calls
emulate_instruction() from io_interception() (svm.c) and from handle_io()
(vmx.c).  It removes all vmx/svm prefix instruction decoders
(get_addr_size(), io_get_override(), io_address(), get_io_count())

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:23 +02:00
Laurent Vivier
cebff02b11 KVM: Change the emulator_{read,write,cmpxchg}_* functions to take a vcpu
... instead of a x86_emulate_ctxt, so that other callers can use it easily.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:21 +02:00
Aurelien Jarno
3ccb8827fb KVM: Remove dead code in the cmpxchg instruction emulation
The writeback fixes (02c03a326a) let
some dead code in the cmpxchg instruction emulation. Remove it.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:19 +02:00
Avi Kivity
394b6e5944 KVM: x86 emulator: fix faulty check for two-byte opcode
Right now, the bug is harmless as we never emulate one-byte 0xb6 or 0xb7.
But things may change.

Noted by the mysterious Gabriel C.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:19 +02:00
Avi Kivity
e3243452f4 KVM: x86 emulator: fix cmov for writeback changes
The writeback fixes (02c03a326a) broke
cmov emulation.  Fix.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:19 +02:00
Rusty Russell
dcc0766b22 KVM: Trivial: Comment spelling may escape grep
Speling error in comment.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:18 +02:00
Rusty Russell
1e3c5cb0d5 KVM: Trivial: Make decode_register() static
I have shied away from touching x86_emulate.c (it could definitely use
some love, but it is forked from the Xen code, and it would be more
productive to cross-merge fixes).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13 10:18:18 +02:00
Avi Kivity
bac27d35cb KVM: x86 emulator: fix debug reg mov instructions
More fallout from the writeback fixes: debug register transfer
instructions do their own writeback and thus need to disable the general
writeback mechanism.

This fixes oopses and some guest failures on AMD machines (the Intel
variant decodes the instruction in hardware and thus does not need
emulation).

Cc: Alistair John Strachan <alistair@devzero.co.uk>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-06 17:54:41 -07:00
Aurelien Jarno
d37c855719 KVM: disable writeback for 0x0f 0x01 instructions.
0x0f 0x01 instructions (ie lgdt, lidt, smsw, lmsw and invlpg) does
not use writeback. This patch set no_wb=1 when emulating those
instructions.

This fixes a regression booting the FreeBSD kernel on AMD.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-25 14:31:27 +03:00
Avi Kivity
35f3f28613 KVM: x86 emulator: implement rdmsr and wrmsr
Allow real-mode emulation of rdmsr and wrmsr.  This allows smp Windows to
boot, presumably for its sipi trampoline.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-20 20:16:29 +03:00
Luca Tettamanti
02c03a326a KVM: Fix x86 emulator writeback
When the old value and new one are the same the emulator skips the
write; this is undesirable when the destination is a MMIO area and the
write shall be performed regardless of the previous value. This
optimization breaks e.g. a Linux guest APIC compiled without
X86_GOOD_APIC.

Remove the check and perform the writeback stage in the emulation unless
it's explicitly disabled (currently push and some 2 bytes instructions
may disable the writeback).

Signed-Off-By: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16 12:05:48 +03:00
Nitin A Kamble
d9413cd757 KVM: Implement emulation of instruction "ret" (opcode 0xc3)
Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16 12:05:47 +03:00
Nitin A Kamble
7f0aaee07b KVM: Implement emulation of "pop reg" instruction (opcode 0x58-0x5f)
For use in real mode.

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16 12:05:47 +03:00
Avi Kivity
72d6e5a08a KVM: Emulate hlt on real mode for Intel
This has two use cases: the bios can't boot from disk, and guest smp
bootstrap.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16 12:05:46 +03:00
Avi Kivity
687fdbfe64 KVM: x86 emulator: implement wbinvd
Vista seems to trigger it.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16 12:05:42 +03:00
Avi Kivity
4c690a1e86 KVM: Allow passing 64-bit values to the emulated read/write API
This simplifies the API somewhat (by eliminating the special-case
cmpxchg8b on i386).

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:31 +03:00
Avi Kivity
df513e2cdd KVM: x86 emulator: fix bit string operations operand size
On x86, bit operations operate on a string of bits that can reside in
multiple words.  For example, 'btsl %eax, (blah)' will touch the word
at blah+4 if %eax is between 32 and 63.

The x86 emulator compensates for that by advancing the operand address
by (bit offset / BITS_PER_LONG) and truncating the bit offset to the
range (0..BITS_PER_LONG-1).  This has a side effect of forcing the operand
size to 8 bytes on 64-bit hosts.

Now, a 32-bit guest goes and fork()s a process.  It write protects a stack
page at 0xbffff000 using the 'btr' instruction, at offset 0xffc in the page
table, with bit offset 1 (for the write permission bit).

The emulator now forces the operand size to 8 bytes as previously described,
and an innocent page table update turns into a cross-page-boundary write,
which is assumed by the mmu code not to be a page table, so it doesn't
actually clear the corresponding shadow page table entry.  The guest and
host permissions are out of sync and guest memory is corrupted soon
afterwards, leading to guest failure.

Fix by not using BITS_PER_LONG as the word size; instead use the actual
operand size, so we get a 32-bit write in that case.

Note we still have to teach the mmu to handle cross-page-boundary writes
to guest page table; but for now this allows Damn Small Linux 0.4 (2.4.20)
to boot.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Avi Kivity
038e51de2e [PATCH] KVM: x86 emulator: fix bit string instructions
The various bit string instructions (bts, btc, etc.) fail to adjust the
address correctly if the bit address is beyond BITS_PER_LONG.

This bug creeped in as the emulator originally relied on cr2 to contain the
memory address; however we now decode it from the mod r/m bits, and must
adjust the offset to account for large bit indices.

The patch is rather large because it switches src and dst decoding around, so
that the bit index is available when decoding the memory address.

This fixes workloads like the FC5 installer.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-23 07:52:06 -08:00
Avi Kivity
32b3562735 [PATCH] KVM: MMU: Fix cmpxchg8b emulation
cmpxchg8b uses edx:eax as the compare operand, not edi:eax.

cmpxchg8b is used by 32-bit pae guests to set page table entries atomically,
and this is emulated touching shadowed guest page tables.

Also, implement it for 32-bit hosts.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05 23:55:26 -08:00
Avi Kivity
05b3e0c2c7 [PATCH] KVM: Replace __x86_64__ with CONFIG_X86_64
As per akpm's request.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13 09:05:46 -08:00
Avi Kivity
6aa8b732ca [PATCH] kvm: userspace interface
web site: http://kvm.sourceforge.net

mailing list: kvm-devel@lists.sourceforge.net
  (http://lists.sourceforge.net/lists/listinfo/kvm-devel)

The following patchset adds a driver for Intel's hardware virtualization
extensions to the x86 architecture.  The driver adds a character device
(/dev/kvm) that exposes the virtualization capabilities to userspace.  Using
this driver, a process can run a virtual machine (a "guest") in a fully
virtualized PC containing its own virtual hard disks, network adapters, and
display.

Using this driver, one can start multiple virtual machines on a host.

Each virtual machine is a process on the host; a virtual cpu is a thread in
that process.  kill(1), nice(1), top(1) work as expected.  In effect, the
driver adds a third execution mode to the existing two: we now have kernel
mode, user mode, and guest mode.  Guest mode has its own address space mapping
guest physical memory (which is accessible to user mode by mmap()ing
/dev/kvm).  Guest mode has no access to any I/O devices; any such access is
intercepted and directed to user mode for emulation.

The driver supports i386 and x86_64 hosts and guests.  All combinations are
allowed except x86_64 guest on i386 host.  For i386 guests and hosts, both pae
and non-pae paging modes are supported.

SMP hosts and UP guests are supported.  At the moment only Intel
hardware is supported, but AMD virtualization support is being worked on.

Performance currently is non-stellar due to the naive implementation of the
mmu virtualization, which throws away most of the shadow page table entries
every context switch.  We plan to address this in two ways:

- cache shadow page tables across tlb flushes
- wait until AMD and Intel release processors with nested page tables

Currently a virtual desktop is responsive but consumes a lot of CPU.  Under
Windows I tried playing pinball and watching a few flash movies; with a recent
CPU one can hardly feel the virtualization.  Linux/X is slower, probably due
to X being in a separate process.

In addition to the driver, you need a slightly modified qemu to provide I/O
device emulation and the BIOS.

Caveats (akpm: might no longer be true):

- The Windows install currently bluescreens due to a problem with the
  virtual APIC.  We are working on a fix.  A temporary workaround is to
  use an existing image or install through qemu
- Windows 64-bit does not work.  That's also true for qemu, so it's
  probably a problem with the device model.

[bero@arklinux.org: build fix]
[simon.kagstrom@bth.se: build fix, other fixes]
[uril@qumranet.com: KVM: Expose interrupt bitmap]
[akpm@osdl.org: i386 build fix]
[mingo@elte.hu: i386 fixes]
[rdreier@cisco.com: add log levels to all printks]
[randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings]
[anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support]
Signed-off-by: Yaniv Kamay <yaniv@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Simon Kagstrom <simon.kagstrom@bth.se>
Cc: Bernhard Rosenkraenzer <bero@arklinux.org>
Signed-off-by: Uri Lublin <uril@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:22 -08:00