6998 Commits

Author SHA1 Message Date
neel
20e3e8762f If a vcpu has issued a HLT instruction with interrupts disabled then it sleeps
forever in vm_handle_hlt().

This is usually not an issue as long as one of the other vcpus properly resets
or powers off the virtual machine. However, if the bhyve(8) process is killed
with a signal the halted vcpu cannot be woken up because it's sleep cannot be
interrupted.

Fix this by waking up periodically and returning from vm_handle_hlt() if
TDF_ASTPENDING is set.

Reported by:	Leon Dang
Sponsored by:	Nahanni Systems
2014-07-26 02:53:51 +00:00
neel
62d591cec9 Don't return -1 from the push emulation handler. Negative return values are
interpreted specially on return from sys_ioctl() and may cause undesirable
side-effects like restarting the system call.
2014-07-26 02:51:46 +00:00
neel
563faffd70 Fix a couple of issues in the PUSH emulation:
It is not possible to PUSH a 32-bit operand on the stack in 64-bit mode. The
default operand size for PUSH is 64-bits and the operand size override prefix
changes that to 16-bits.

vm_copy_setup() can return '1' if it encounters a fault when walking the
guest page tables. This is a guest issue and is now handled properly by
resuming the guest to handle the fault.
2014-07-24 23:01:53 +00:00
marius
3179fa4baa Copying pages via temporary mappings in the !DMAP case of pmap_copy_pages()
involves updating the corresponding page tables followed by accesses to the
pages in question. This sequence is subject to the situation exactly described
in the "AMD64 Architecture Programmer's Manual Volume 2: System Programming"
rev. 3.23, "7.3.1 Special Coherency Considerations" [1, p. 171 f.]. Therefore,
issuing the INVLPG right after modifying the PTE bits is crucial (see also
r269050).
For the amd64 PMAP code, the order of instructions was already correct. The
above fact still is worth documenting, though.

1: http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2012/10/24593_APM_v21.pdf

Reviewed by:	alc
Sponsored by:	Bally Wulff Games & Entertainment GmbH
2014-07-24 10:12:22 +00:00
neel
4535fa67c4 Fix fault injection in bhyve.
The faulting instruction needs to be restarted when the exception handler
is done handling the fault. bhyve now does this correctly by setting
'vmexit[vcpu].inst_length' to zero so the %rip is not advanced.

A minor complication is that the fault injection APIs are used by instruction
emulation code that is shared by vmm.ko and bhyve. Thus the argument that
refers to 'struct vm *' in kernel or 'struct vmctx *' in userspace needs to
be loosely typed as a 'void *'.
2014-07-24 01:38:11 +00:00
royger
0ee303bbe3 don't set CR4 PSE bit on amd64
Setting PSE together with PAE or in long mode just makes the PSE bit
completely ignored, so don't set it.

Sponsored by: Citrix Systems R&D
Reviewed by: kib
2014-07-23 15:53:29 +00:00
neel
e972917c13 Emulate instructions emitted by OpenBSD/i386 version 5.5:
- CMP REG, r/m
- MOV AX/EAX/RAX, moffset
- MOV moffset, AX/EAX/RAX
- PUSH r/m
2014-07-23 04:28:51 +00:00
emaste
56b12303b3 Don't pass null kmdp to preload_search_info
On Xen PVH guests kmdp == NULL.

Submitted by:	royger
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation
2014-07-22 13:58:33 +00:00
markj
07a0bd68a5 Fix the build when DTrace isn't enabled.
Reported by:	stefanf
X-MFC-With:	r268600
2014-07-20 18:44:56 +00:00
neel
7b1204cc02 Fix build without INVARIANTS defined by getting rid of unused variable 'exc'.
Reported by:	adrian, stefanf
2014-07-20 16:34:35 +00:00
neel
1f15eea2e0 Handle nested exceptions in bhyve.
A nested exception condition arises when a second exception is triggered while
delivering the first exception. Most nested exceptions can be handled serially
but some are converted into a double fault. If an exception is generated during
delivery of a double fault then the virtual machine shuts down as a result of
a triple fault.

vm_exit_intinfo() is used to record that a VM-exit happened while an event was
being delivered through the IDT. If an exception is triggered while handling
the VM-exit it will be treated like a nested exception.

vm_entry_intinfo() is used by processor-specific code to get the event to be
injected into the guest on the next VM-entry. This function is responsible for
deciding the disposition of nested exceptions.
2014-07-19 20:59:08 +00:00
markj
e18e12eeda Use a C wrapper for trap() instead of checking and calling the DTrace trap
hook in assembly.

Suggested by:	kib
Reviewed by:	kib (original version)
X-MFC-With:	r268600
2014-07-19 02:27:31 +00:00
neel
5046d9cb8a Add emulation for legacy x86 task switching mechanism.
FreeBSD/i386 uses task switching to handle double fault exceptions and this
change enables that to work.

Reported by:	glebius
2014-07-16 21:26:26 +00:00
neel
eb07e4ed55 Add support for operand size and address size override prefixes in bhyve's
instruction emulation [1].

Fix bug in emulation of opcode 0x8A where the destination is a legacy high
byte register and the guest vcpu is in 32-bit mode. Prior to this change
instead of modifying %ah, %bh, %ch or %dh the emulation would end up
modifying %spl, %bpl, %sil or %dil instead.

Add support for moffsets by treating it as a 2, 4 or 8 byte immediate value
during instruction decoding.

Fix bug in verify_gla() where the linear address computed after decoding
the instruction was not being truncated to the effective address size [2].

Tested by:	Leon Dang [1]
Reported by:	Peter Grehan [2]
Sponsored by:	Nahanni Systems
2014-07-15 17:37:17 +00:00
kib
1ecfe30151 Make amd64 pmap_copy_pages() functional for pages not mapped by DMAP.
Requested and reviewed by:	royger
Tested by:	pho, royger
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-07-15 09:30:43 +00:00
markj
880dd1a983 Invoke the DTrace trap handler before calling trap() on amd64. This matches
the upstream implementation and helps ensure that a trap induced by tracing
fbt::trap:entry is handled without recursively generating another trap.

This makes it possible to run most (but not all) of the DTrace tests under
common/safety/ without triggering a kernel panic.

Submitted by:	Anton Rang <anton.rang@isilon.com> (original version)
Phabric:	D95
2014-07-14 04:38:17 +00:00
neel
307c44649f Use the correct offset when converting a logical address (segment:offset)
to a linear address.
2014-07-11 01:23:38 +00:00
kib
729061be23 For safety, ensure that any consumer of the set_regs() and
ptrace_set_pc() use the correct return to userspace using iret.

The signal return, PT_CONTINUE (which in fact uses signal return path)
set the pcb flag already.  The setcontext(2) enforces iret return when
%rip is incorrect.  Due to this, the change is redundand, but is made
to ensure that no path which modifies context, forgets to set
PCB_FULL_IRET.

Inspired by:	CVE-2014-4699
Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-07-09 21:39:40 +00:00
neel
845f7be2e3 Accurately identify the vcpu's operating mode as 64-bit, compatibility,
protected or real.
2014-07-08 21:48:57 +00:00
neel
d5633f89da Invalidate guest TLB mappings as a side-effect of its CR3 being updated.
This is a pre-requisite for task switch emulation since the CR3 is loaded
from the new TSS.
2014-07-08 20:51:03 +00:00
kib
ae88c29379 Correct si_code for the SIGBUS signal generated by the alignment trap.
Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-07-08 08:05:42 +00:00
alc
d74e85dbb9 Introduce pmap_unwire(). It will replace pmap_change_wiring(). There are
several reasons for this change:

pmap_change_wiring() has never (in my memory) been used to set the wired
attribute on a virtual page.  We have always used pmap_enter() to do that.
Moreover, it is not really safe to use pmap_change_wiring() to set the wired
attribute on a virtual page.  The description of pmap_change_wiring() says
that it assumes the existence of a mapping in the pmap.  However, non-wired
mappings may be reclaimed by the pmap at any time.  (See pmap_collect().)
Many implementations of pmap_change_wiring() will crash if the mapping does
not exist.

pmap_unwire() accepts a range of virtual addresses, whereas
pmap_change_wiring() acts upon a single virtual page.  Since we are
typically unwiring a range of virtual addresses, pmap_unwire() will be more
efficient.  Moreover, pmap_unwire() allows us to unwire superpage mappings.
Previously, we were forced to demote the superpage mapping, because
pmap_change_wiring() only allowed us to express the unwiring of a single
base page mapping at a time.  This added to the overhead of unwiring for
large ranges of addresses, including the implicit unwiring that occurs at
process termination.

Implementations for arm and powerpc will follow.

Discussed with:	jeff, marcel
Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
2014-07-06 17:42:38 +00:00
emaste
9825a4c806 Prefer vt(4) for UEFI boot
The UEFI framebuffer driver vt_efifb requires vt(4), so add a mechanism
for the startup routine to set the preferred console.  This change is
ugly because console init happens very early in the boot, making a
cleaner interface difficult.  This change is intended only to facilitate
the sc(4) / vt(4) transition, and can be reverted once vt(4) is the
default.
2014-07-02 13:24:21 +00:00
emaste
10d8b7a43b Add vt(4) devices and options to NOTES
Reviewed by:	marius (earlier version)
2014-07-01 00:22:54 +00:00
emaste
e6dbbf35ca Add vt(4) to GENERIC and retire the separate VT config
vt(4) and sc(4) can now coexist in the same kernel.  To choose the vt
driver, set the loader tunable kern.vty=vt .
2014-06-30 16:18:38 +00:00
hselasky
35b126e324 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
gjb
fc21f40567 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
hselasky
bd1ed65f0f Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
tychon
816d8c3faa Add support for emulating the move instruction: "mov r/m8, imm8".
Reviewed by:	neel
2014-06-26 17:15:41 +00:00
grehan
54db9f3822 Expose the amount of resident and wired memory from the guest's vmspace.
This is different than the amount shown for the process e.g. by
/usr/bin/top - that is the mappings faulted in by the mmap'd region
of guest memory.

The values can be fetched with bhyvectl

 # bhyvectl --get-stats --vm=myvm
 ...
 Resident memory                         	413749248
 Wired memory                            	0
 ...

vmm_stat.[ch] -
 Modify the counter code in bhyve to allow direct setting of a counter
as opposed to incrementing, and providing a callback to fetch a
counter's value.

Reviewed by:	neel
2014-06-25 22:13:35 +00:00
kib
fe547198b1 Add FPU_KERN_KTHR flag to fpu_kern_enter(9), which avoids saving FPU
context into memory for the kernel threads which called
fpu_kern_thread(9).  This allows the fpu_kern_enter() callers to not
check for is_fpu_kern_thread() to get the optimization.

Apply the flag to padlock(4) and aesni(4).  In aesni_cipher_process(),
do not leak FPU context state on error.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-06-23 07:37:54 +00:00
dchagin
dd6bed9dd2 Revert r266925 as it can lead to instant panic at fexecve():
To allow to run the interpreter itself add a new ELF branding type.

Pointed out by:	kib, mjg
2014-06-17 05:29:18 +00:00
tychon
bb415f07f0 Bring an overly enthusiastic KASSERT inline with the Intel SDM.
Reviewed by:	neel
2014-06-16 22:59:18 +00:00
attilio
2802c525ad - Modify vm_page_unwire() and vm_page_enqueue() to directly accept
the queue where to enqueue pages that are going to be unwired.
- Add stronger checks to the enqueue/dequeue for the pagequeues when
  adding and removing pages to them.

Of course, for unmanaged pages the queue parameter of vm_page_unwire() will
be ignored, just as the active parameter today.
This makes adding new pagequeues quicker.

This change effectively modifies the KPI.  __FreeBSD_version will be,
however, bumped just when the full cache of free pages will be
evicted.

Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc
Tested by:	pho
2014-06-16 18:15:27 +00:00
royger
7c7f3fb2d0 amd64/i386: introduce APIC hooks for different APIC implementations.
This is needed for Xen PV(H) guests, since there's no hardware lapic
available on this kind of domains. This commit should not change
functionality.

Sponsored by: Citrix Systems R&D
Reviewed by: jhb
Approved by: gibbs

amd64/include/cpu.h:
amd64/amd64/mp_machdep.c:
i386/include/cpu.h:
i386/i386/mp_machdep.c:
 - Remove lapic_ipi_vectored hook from cpu_ops, since it's now
   implemented in the lapic hooks.

amd64/amd64/mp_machdep.c:
i386/i386/mp_machdep.c:
 - Use lapic_ipi_vectored directly, since it's now an inline function
   that will call the appropiate hook.

x86/x86/local_apic.c:
 - Prefix bare metal public lapic functions with native_ and mark them
   as static.
 - Define default implementation of apic_ops.

x86/include/apicvar.h:
 - Declare the apic_ops structure and create inline functions to
   access the hooks, so the change is transparent to existing users of
   the lapic_ functions.

x86/xen/hvm.c:
 - Switch to use the new apic_ops.
2014-06-16 08:43:03 +00:00
tychon
e250a91c1d Replace enum forward declarations with complete definitions.
Reviewed by:	neel
2014-06-10 18:46:00 +00:00
neel
e48c89801a Add helper functions to populate VM exit information for rendezvous and
astpending exits. This is to reduce code duplication between VT-x and
SVM implementations.
2014-06-10 16:45:58 +00:00
neel
32f7809be1 Turn on interrupt window exiting unconditionally when an ExtINT is being
injected into the guest. This allows the hypervisor to inject another
ExtINT or APIC vector as soon as the guest is able to process interrupts.

This change is not to address any correctness issue but to guarantee that
any pending APIC vector that was preempted by the ExtINT will be injected
as soon as possible. Prior to this change such pending interrupts could be
delayed until the next VM exit.
2014-06-10 01:38:02 +00:00
neel
d4bb0b204a Add reserved bit checking when doing %CR8 emulation and inject #GP if required.
Pointed out by:	grehan
Reviewed by:	tychon
2014-06-09 20:51:08 +00:00
neel
80a67d54c4 Add ioctl(VM_REINIT) to reinitialize the virtual machine state maintained
by vmm.ko. This allows the virtual machine to be restarted without having
to destroy it first.

Reviewed by:	grehan
2014-06-07 21:36:52 +00:00
alc
39548e640f Add a page size field to struct vm_page. Increase the page size field when
a partially populated reservation becomes fully populated, and decrease this
field when a fully populated reservation becomes partially populated.

Use this field to simplify the implementation of pmap_enter_object() on
amd64, arm, and i386.

On all architectures where we support superpages, the cost of creating a
superpage mapping is roughly the same as creating a base page mapping.  For
example, both kinds of mappings entail the creation of a single PTE and PV
entry.  With this in mind, use the page size field to make the
implementation of vm_map_pmap_enter(..., MAP_PREFAULT_PARTIAL) a little
smarter.  Previously, if MAP_PREFAULT_PARTIAL was specified to
vm_map_pmap_enter(), that function would only map base pages.  Now, it will
create up to 96 base page or superpage mappings.

Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
2014-06-07 17:12:26 +00:00
tychon
c04c953593 Support guest accesses to %cr8.
Reviewed by:	neel
2014-06-06 18:23:49 +00:00
imp
7694525189 Restore comments accidentally removed.
MFC after: 3 days
2014-06-06 04:08:55 +00:00
neel
9c2a942387 Activate vcpus from bhyve(8) using the ioctl VM_ACTIVATE_CPU instead of doing
it implicitly in vmm.ko.

Add ioctl VM_GET_CPUS to get the current set of 'active' and 'suspended' cpus
and display them via /usr/sbin/bhyvectl using the "--get-active-cpus" and
"--get-suspended-cpus" options.

This is in preparation for being able to reset virtual machine state without
having to destroy and recreate it.
2014-05-31 23:37:34 +00:00
dchagin
538f396887 To allow to run the interpreter itself add a new ELF branding type.
Allow Linux ABI to run ELF interpreter.

MFC after:	3 days
2014-05-31 15:01:51 +00:00
tychon
61025dc75e If VMX isn't enabled so long as the lock bit isn't set yet in MSR
IA32_FEATURE_CONTROL it still can be.

Approved by:	grehan (co-mentor)
2014-05-30 23:37:31 +00:00
neel
0a0e9fcd5a Remove bogus check for kmem_malloc() failure even though M_WAITOK is set.
Requested by:	jkim
2014-05-30 20:58:32 +00:00
neel
aefe217075 Allocate a zeroed LDT.
Failing to do this might result in the LDT appearing to run out of free
descriptors because of random junk in the descriptor's 'sd_type' field.

http://lists.freebsd.org/pipermail/freebsd-amd64/2014-May/016088.html

Reviewed by:	kib
MFC after:	2 weeks
2014-05-30 18:59:37 +00:00
kib
7c98ae3376 When usermode loaded non-default segment selector into the %gs,
correctly prepare KGSBASE msr to restore the user descriptor base on
the last swapgs during return to usermode.

Reported and tested by:	peterj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-05-29 16:18:31 +00:00
markj
4c818572b7 Commit the rest of the changes that were intended to be part of r266826.
X-MFC-with:	r266826
2014-05-29 01:42:22 +00:00