hw.x2apic_enable tunable allows disabling it from the loader prompt.
To closely repeat effects of the uncached memory ops when accessing
registers in the xAPIC mode, the x2APIC writes to MSRs are preceeded
by mfence, except for the EOI notifications. This is probably too
strict, only ICR writes to send IPI require serialization to ensure
that other CPUs see the previous actions when IPI is delivered. This
may be changed later.
In vmm justreturn IPI handler, call doreti_iret instead of doing iretd
inline, to handle corner conditions.
Note that the patch only switches LAPICs into x2APIC mode. It does not
enables FreeBSD to support > 255 CPUs, which requires parsing x2APIC
MADT entries and doing interrupts remapping, but is the required step
on the way.
Reviewed by: neel
Tested by: pho (real hardware), neel (on bhyve)
Discussed with: jhb, grehan
Sponsored by: The FreeBSD Foundation
MFC after: 2 months
KVM clock shares the same data structures between the guest and the host
as Xen so it makes sense to just have a single copy of this code.
Differential Revision: https://reviews.freebsd.org/D1429
Reviewed by: royger (eariler version)
MFC after: 1 month
These instructions are emitted by 'bus_space_read_region()' when accessing
MMIO regions.
Since MOVS can be used with a repeat prefix start decoding the REPZ and
REPNZ prefixes. Also start decoding the segment override prefix since MOVS
allows overriding the source operand segment register.
Tested by: tychon
MFC after: 1 week
Keep track of the next instruction to be executed by the vcpu as 'nextrip'.
As a result the VM_RUN ioctl no longer takes the %rip where a vcpu should
start execution.
Also, instruction restart happens implicitly via 'vm_inject_exception()' or
explicitly via 'vm_restart_instruction()'. The APIs behave identically in
both kernel and userspace contexts. The main beneficiary is the instruction
emulation code that executes in both contexts.
bhyve(8) VM exit handlers now treat 'vmexit->rip' and 'vmexit->inst_length'
as readonly:
- Restarting an instruction is now done by calling 'vm_restart_instruction()'
as opposed to setting 'vmexit->inst_length' to 0 (e.g. emulate_inout())
- Resuming vcpu at an arbitrary %rip is now done by setting VM_REG_GUEST_RIP
as opposed to changing 'vmexit->rip' (e.g. vmexit_task_switch())
Differential Revision: https://reviews.freebsd.org/D1526
Reviewed by: grehan
MFC after: 2 weeks
Implement a subset of the multiboot specification in order to boot Xen
and a FreeBSD Dom0 from the FreeBSD bootloader. This multiboot
implementation is tailored to boot Xen and FreeBSD Dom0, and it will
most surely fail to boot any other multiboot compilant kernel.
In order to detect and boot the Xen microkernel, two new file formats
are added to the bootloader, multiboot and multiboot_obj. Multiboot
support must be tested before regular ELF support, since Xen is a
multiboot kernel that also uses ELF. After a multiboot kernel is
detected, all the other loaded kernels/modules are parsed by the
multiboot_obj format.
The layout of the loaded objects in memory is the following; first the
Xen kernel is loaded as a 32bit ELF into memory (Xen will switch to
long mode by itself), after that the FreeBSD kernel is loaded as a RAW
file (Xen will parse and load it using it's internal ELF loader), and
finally the metadata and the modules are loaded using the native
FreeBSD way. After everything is loaded we jump into Xen's entry point
using a small trampoline. The order of the multiboot modules passed to
Xen is the following, the first module is the RAW FreeBSD kernel, and
the second module is the metadata and the FreeBSD modules.
Since Xen will relocate the memory position of the second
multiboot module (the one that contains the metadata and native
FreeBSD modules), we need to stash the original modulep address inside
of the metadata itself in order to recalculate its position once
booted. This also means the metadata must come before the loaded
modules, so after loading the FreeBSD kernel a portion of memory is
reserved in order to place the metadata before booting.
In order to tell the loader to boot Xen and then the FreeBSD kernel the
following has to be added to the /boot/loader.conf file:
xen_cmdline="dom0_mem=1024M dom0_max_vcpus=2 dom0pvh=1 console=com1,vga"
xen_kernel="/boot/xen"
The first argument contains the command line that will be passed to the Xen
kernel, while the second argument is the path to the Xen kernel itself. This
can also be done manually from the loader command line, by for example
typing the following set of commands:
OK unload
OK load /boot/xen dom0_mem=1024M dom0_max_vcpus=2 dom0pvh=1 console=com1,vga
OK load kernel
OK load zfs
OK load if_tap
OK load ...
OK boot
Sponsored by: Citrix Systems R&D
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D517
For the Forth bits:
Submitted by: Julien Grall <julien.grall AT citrix.com>
VM_INJECT_EXCEPTION ioctl. However it morphed into other uses like keeping
track pending exceptions for a vcpu. This in turn causes confusion because
some fields in 'struct vm_exception' like 'vcpuid' make sense only in the
ioctl context. It also makes it harder to add or remove structure fields.
Fix this by using 'struct vm_exception' only to communicate information
from userspace to vmm.ko when injecting an exception.
Also, add a field 'restart_instruction' to 'struct vm_exception'. This
field is set to '1' for exceptions where the faulting instruction is
restarted after the exception is handled.
MFC after: 1 week
Features by CPUID as CPUID.80000008H:EAX[7:0], into variable cpu_maxphyaddr.
Reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
code in sys/kern/kern_dump.c. Most dumpsys() implementations are nearly
identical and simply redefine a number of constants and helper subroutines;
a generic implementation will make it easier to implement features around
kernel core dumps. This change does not alter any minidump code and should
have no functional impact.
PR: 193873
Differential Revision: https://reviews.freebsd.org/D904
Submitted by: Conrad Meyer <conrad.meyer@isilon.com>
Reviewed by: jhibbits (earlier version)
Sponsored by: EMC / Isilon Storage Division
managing pages from different address ranges. Generally speaking, this
feature is used to increase the likelihood that physical pages are
available that can meet special DMA requirements or can be accessed through
a limited-coverage direct mapping (e.g., MIPS). However, prior to this
change, the configuration of the free lists was static, i.e., it was
determined at compile time. Consequentally, free lists could be created
for address ranges that held no actual pages, for example, on 32-bit MIPS-
based systems with 512 MB or less of physical memory. This change makes
the creation of the free lists dynamic, i.e., it is based on the available
physical memory at boot time.
On 64-bit x86-based systems with 64 GB or more of physical memory, create
free lists for managing pages with physical addresses below 4 GB. This
change is to address reported problems with initializing devices that
require the allocation of physical pages below 4 GB on some systems with
128 GB or more of physical memory.
PR: 185727
Differential Revision: https://reviews.freebsd.org/D1274
Reviewed by: jhb, kib
MFC after: 3 weeks
Sponsored by: EMC / Isilon Storage Division
The new RTC emulation supports all interrupt modes: periodic, update ended
and alarm. It is also capable of maintaining the date/time and NVRAM contents
across virtual machine reset. Also, the date/time fields can now be modified
by the guest.
Since bhyve now emulates both the PIT and the RTC there is no need for
"Legacy Replacement Routing" in the HPET so get rid of it.
The RTC device state can be inspected via bhyvectl as follows:
bhyvectl --vm=vm --get-rtc-time
bhyvectl --vm=vm --set-rtc-time=<unix_time_secs>
bhyvectl --vm=vm --rtc-nvram-offset=<offset> --get-rtc-nvram
bhyvectl --vm=vm --rtc-nvram-offset=<offset> --set-rtc-nvram=<value>
Reviewed by: tychon
Discussed with: grehan
Differential Revision: https://reviews.freebsd.org/D1385
MFC after: 2 weeks
"hw.vmm.trace_guest_exceptions". To enable this feature set the tunable
to "1" before loading vmm.ko.
Tracing the guest exceptions can be useful when debugging guest triple faults.
Note that there is a performance impact when exception tracing is enabled
since every exception will now trigger a VM-exit.
Also, handle machine check exceptions that happen during guest execution
by vectoring to the host's machine check handler via "int $18".
Discussed with: grehan
MFC after: 2 weeks
It is automatically set when -fPIC is passed to the compiler.
Reviewed by: dim, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1179
In vt_efifb_init the framebuffer's physaddr is passed to PHYS_TO_DMAP
before the DMAP is setup. The result is not actually accessed until
after the mapping is setup, though. Loosen the assertion in PHYS_TO_DMAP
for now, to allow use when dmaplimit == 0.
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1142
- Move the existing code to x86/x86/identcpu.c since it is x86-specific.
- If the CPUID2_HV flag is set, assume a hypervisor is present and query
the 0x40000000 leaf to determine the hypervisor vendor ID. Export the
vendor ID and the highest supported hypervisor CPUID leaf via
hv_vendor[] and hv_high variables, respectively. The hv_vendor[]
array is also exported via the hw.hv_vendor sysctl.
- Merge the VMWare detection code from tsc.c into the new probe in
identcpu.c. Add a VM_GUEST_VMWARE to identify vmware and use that in
the TSC code to identify VMWare.
Differential Revision: https://reviews.freebsd.org/D1010
Reviewed by: delphij, jkim, neel
This reduces variability during timer calibration by keeping the emulation
"close" to the guest. Additionally having all timer emulations in the kernel
will ease the transition to a per-VM clock source (as opposed to using the
host's uptime keep track of time).
Discussed with: grehan
Place the code introduced in r268660 into a separate function that can be
called from uiomove_fromphys. Instead of pre-allocating two KVA pages use
vmem_alloc to allocate them on demand when needed. This prevents blocking if
a page fault is taken while physical addresses from outside the DMAP are
used, since the lock is now removed.
Also introduce a safety catch in PHYS_TO_DMAP and DMAP_TO_PHYS.
Sponsored by: Citrix Systems R&D
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D947
amd64/amd64/pmap.c:
- Factor out the code to deal with non DMAP addresses from pmap_copy_pages
and place it in pmap_map_io_transient.
- Change the code to use vmem_alloc instead of a set of pre-allocated
pages.
- Use pmap_qenter and don't pin the thread if there can be page faults.
amd64/amd64/uio_machdep.c:
- Use pmap_map_io_transient in order to correctly deal with physical
addresses not covered by the DMAP.
amd64/include/pmap.h:
- Add the prototypes for the new functions.
amd64/include/vmparam.h:
- Add safety catches to make sure PHYS_TO_DMAP and DMAP_TO_PHYS are only
used with addresses covered by the DMAP.
This device is only attached to priviledged domains, and allows the
toolstack to interact with Xen. The two functions of the privcmd
interface is to allow the execution of hypercalls from user-space, and
the mapping of foreign domain memory.
Sponsored by: Citrix Systems R&D
i386/include/xen/hypercall.h:
amd64/include/xen/hypercall.h:
- Introduce a function to make generic hypercalls into Xen.
xen/interface/xen.h:
xen/interface/memory.h:
- Import the new hypercall XENMEM_add_to_physmap_range used by
auto-translated guests to map memory from foreign domains.
dev/xen/privcmd/privcmd.c:
- This device has the following functions:
- Allow user-space applications to make hypercalls into Xen.
- Allow user-space applications to map memory from foreign domains,
this is accomplished using the newly introduced hypercall
(XENMEM_add_to_physmap_range).
xen/privcmd.h:
- Public ioctl interface for the privcmd device.
x86/xen/hvm.c:
- Remove declaration of hypercall_page, now it's declared in
hypercall.h.
conf/files:
- Add the privcmd device to the build process.
forced invalidation of the cache range regardless of the presence of
self-snoop feature. Some recent Intel GPUs in some modes are not
coherent, and dirty lines in CPU cache must be flushed before the
pages are transferred to GPU domain.
Reviewed by: alc (previous version)
Tested by: pho (amd64)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The hypervisor hides the MONITOR/MWAIT capability by unconditionally setting
CPUID.01H:ECX[3] to 0 so the guest should not expect these instructions to
be present anyways.
Discussed with: grehan
code. There are only a handful of MSRs common between the two so there isn't
too much duplicate functionality.
The VT-x code has the following types of MSRs:
- MSRs that are unconditionally saved/restored on every guest/host context
switch (e.g., MSR_GSBASE).
- MSRs that are restored to guest values on entry to vmx_run() and saved
before returning. This is an optimization for MSRs that are not used in
host kernel context (e.g., MSR_KGSBASE).
- MSRs that are emulated and every access by the guest causes a trap into
the hypervisor (e.g., MSR_IA32_MISC_ENABLE).
Reviewed by: grehan
VM-exit and ultimately on whether nRIP is valid. This allows us to update
the %rip after the emulation is finished so any exceptions triggered during
the emulation will point to the right instruction.
Don't attempt to handle INS/OUTS VM-exits unless the DecodeAssist capability
is available. The effective segment field in EXITINFO1 is not valid without
this capability.
Add VM_EXITCODE_SVM to flag SVM VM-exits that cannot be handled. Provide the
VMCB fields exitinfo1 and exitinfo2 as collateral to help with debugging.
Provide a SVM VM-exit handler to dump the exitcode, exitinfo1 and exitinfo2
fields in bhyve(8).
Reviewed by: Anish Gupta (akgupt3@gmail.com)
Reviewed by: grehan
instruction bytes in the VMCB on a nested page fault. This is useful because
it saves having to walk the guest page tables to fetch the instruction.
vie_init() now takes two additional parameters 'inst_bytes' and 'inst_len'
that map directly to 'vie->inst[]' and 'vie->num_valid'.
The instruction emulation handler skips calling 'vmm_fetch_instruction()'
if 'vie->num_valid' is non-zero.
The use of this capability can be turned off by setting the sysctl/tunable
'hw.vmm.svm.disable_npf_assist' to '1'.
Reviewed by: Anish Gupta (akgupt3@gmail.com)
Discussed with: grehan
by explicitly moving it out of the interrupt shadow. The hypervisor is done
"executing" the HLT and by definition this moves the vcpu out of the
1-instruction interrupt shadow.
Prior to this change the interrupt would be held pending because the VMCS
guest-interruptibility-state would indicate that "blocking by STI" was in
effect. This resulted in an unnecessary round trip into the guest before
the pending interrupt could be injected.
Reviewed by: grehan
resume that is a superset of a pcb. Move the FPU state out of the pcb and
into this new structure. As part of this, move the FPU resume code on
amd64 into a C function. This allows resumectx() to still operate only on
a pcb and more closely mirrors the i386 code.
Reviewed by: kib (earlier version)
<machine/md_var.h>.
- Move some CPU-related variables out of i386/i386/identcpu.c to
initcpu.c to match amd64.
- Move the declaration of has_f00f_hack out of identcpu.c to machdep.c.
- Remove a misleading comment from i386/i386/initcpu.c (locore zeros
the BSS before it calls identify_cpu()) and remove explicit zero
assignments to reduce the diff with amd64.
optional attributes field.
- Add a 'machdep.smap' sysctl that exports the SMAP table of the running
system as an array of the ACPI 3.0 structure. (On older systems, the
attributes are given a value of zero.) Note that the sysctl only
exports the SMAP table if it is available via the metadata passed from
the loader to the kernel. If an SMAP is not available, an empty array
is returned.
- Add a format handler for the ACPI 3.0 SMAP structure to the sysctl(8)
binary to format the SMAP structures in a readable format similar to
the format found in boot messages.
MFC after: 2 weeks
Eventually, the vmd_segs of the struct vm_domain should become bitset
instead of long, to allow arbitrary compile-time selected maximum.
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The MD allocators were very common, however there were some minor
differencies. These differencies were all consolidated in the MI allocator,
under ifdefs. The defines from machine/vmparam.h turn on features required
for a particular machine. For details look in the comment in sys/sf_buf.h.
As result no MD code left in sys/*/*/vm_machdep.c. Some arches still have
machine/sf_buf.h, which is usually quite small.
Tested by: glebius (i386), tuexen (arm32), kevlo (arm32)
Reviewed by: kib
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
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
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 *'.
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.
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
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
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.
