Commit Graph

66 Commits

Author SHA1 Message Date
Neel Natu
b5aaf7b22b Add some more stats to keep track of all the reasons that a vcpu is exiting. 2013-03-30 17:46:03 +00:00
Neel Natu
66f71b7d24 Allow caller to skip 'guest linear address' validation when doing instruction
decode. This is to accomodate hardware assist implementations that do not
provide the 'guest linear address' as part of nested page fault collateral.

Submitted by:	Anish Gupta (akgupt3 at gmail dot com)
2013-03-28 21:26:19 +00:00
Neel Natu
3f23d3ca9f Fix the '-Wtautological-compare' warning emitted by clang for comparing the
unsigned enum type with a negative value.

Obtained from:	NetApp
2013-03-16 22:53:05 +00:00
Neel Natu
61592433eb Allow vmm stats to be specific to the underlying hardware assist technology.
This can be done by using the new macros VMM_STAT_INTEL() and VMM_STAT_AMD().
Statistic counters that are common across the two are defined using VMM_STAT().

Suggested by:	Anish Gupta
Discussed with:	grehan
Obtained from:	NetApp
2013-03-16 22:40:20 +00:00
Neel Natu
25448de222 Requests for invalid CPUID leaves should map to the highest known leaf instead.
Reviewed by:	grehan
Obtained from:	NetApp
2013-02-13 23:22:17 +00:00
Neel Natu
485b3300cc Implement guest vcpu pinning using 'pthread_setaffinity_np(3)'.
Prior to this change pinning was implemented via an ioctl (VM_SET_PINNING)
that called 'sched_bind()' on behalf of the user thread.

The ULE implementation of 'sched_bind()' bumps up 'td_pinned' which in turn
runs afoul of the assertion '(td_pinned == 0)' in userret().

Using the cpuset affinity to implement pinning of the vcpu threads works with
both 4BSD and ULE schedulers and has the happy side-effect of getting rid
of a bunch of code in vmm.ko.

Discussed with:	grehan
2013-02-11 20:36:07 +00:00
Neel Natu
2b89a04496 Fix a broken assumption in the passthru implementation that the MSI-X table
can only be located at the beginning or the end of the BAR.

If the MSI-table is located in the middle of a BAR then we will split the
BAR into two and create two mappings - one before the table and one after
the table - leaving a hole in place of the table so accesses to it can be
trapped and emulated.

Obtained from:	NetApp
2013-02-01 03:49:09 +00:00
Neel Natu
07044a96d8 Increase the number of passthru devices supported by bhyve.
The maximum length of an environment variable puts a limitation on the
number of passthru devices that can be specified via a single variable.
The workaround is to allow user to specify passthru devices via multiple
environment variables instead of a single one.

Obtained from:	NetApp
2013-02-01 01:16:26 +00:00
Neel Natu
8faceb3292 Add emulation support for instruction "88/r: mov r/m8, r8".
This instruction moves a byte from a register to a memory location.

Tested by: tycho nightingale at pluribusnetworks com
2013-01-30 04:09:09 +00:00
Peter Grehan
1fb0ea3f1a Always allow access to the sysenter cs/esp/eip MSRs since they
are automatically saved and restored in the VMCS.

Reviewed by:	neel
Obtained from:	NetApp
2013-01-25 21:38:31 +00:00
Neel Natu
e3f0800bd1 Postpone vmm module initialization until after SMP is initialized - particularly
that 'smp_started != 0'.

This is required because the VT-x initialization calls smp_rendezvous()
to set the CR4_VMXE bit on all the cpus.

With this change we can preload vmm.ko from the loader.

Reported by:	alfred@, sbruno@
Obtained from:	NetApp
2013-01-21 01:33:10 +00:00
Neel Natu
014a52f3a6 There is no need for 'start_emulating()' and 'stop_emulating()' to be defined
in <machine/cpufunc.h> so remove them from there.

Obtained from:	NetApp
2013-01-04 02:49:12 +00:00
Neel Natu
485f986ac9 Modify the default behavior of bhyve such that it no longer forces the use of
x2apic mode on the guest.

The guest can decide whether or not it wants to use legacy mmio or x2apic
access to the APIC by writing to the MSR_APICBASE register.

Obtained from:	NetApp
2012-12-16 01:20:08 +00:00
Peter Grehan
e6f1f347a1 Properly screen for the AND 0x81 instruction from the set
of group1 0x81 instructions that use the reg bits as an
extended opcode.

Still todo: properly update rflags.

Pointed out by:	jilles@
2012-11-30 05:40:24 +00:00
Peter Grehan
b1f95796f0 Remove debug printf.
Pointed out by:	emaste
2012-11-29 15:08:13 +00:00
Peter Grehan
3b2b001107 Add support for the 0x81 AND instruction, now generated
by clang in the local APIC code.

0x81 is a read-modify-write instruction - the EPT check
that only allowed read or write and not both has been
relaxed to allow read and write.

Reviewed by:	neel
Obtained from:	NetApp
2012-11-29 06:26:42 +00:00
Neel Natu
48a29f4e07 Cleanup the user-space paging exit handler now that the unified instruction
emulation is in place.

Obtained from:	NetApp
2012-11-28 13:34:44 +00:00
Neel Natu
b42206f300 Change emulate_rdmsr() and emulate_wrmsr() to return 0 on sucess and errno on
failure. The conversion from the return value to HANDLED or UNHANDLED can be
done locally in vmx_exit_process().

Obtained from: NetApp
2012-11-28 13:10:18 +00:00
Neel Natu
ba9b7bf73a Revamp the x86 instruction emulation in bhyve.
On a nested page table fault the hypervisor will:
- fetch the instruction using the guest %rip and %cr3
- decode the instruction in 'struct vie'
- emulate the instruction in host kernel context for local apic accesses
- any other type of mmio access is punted up to user-space (e.g. ioapic)

The decoded instruction is passed as collateral to the user-space process
that is handling the PAGING exit.

The emulation code is fleshed out to include more addressing modes (e.g. SIB)
and more types of operands (e.g. imm8). The source code is unified into a
single file (vmm_instruction_emul.c) that is compiled into vmm.ko as well
as /usr/sbin/bhyve.

Reviewed by:	grehan
Obtained from:	NetApp
2012-11-28 00:02:17 +00:00
Neel Natu
920bc34090 Fix a bug in the MSI-X resource allocation for PCI passthrough devices.
In the case where the underlying host had disabled MSI-X via the
"hw.pci.enable_msix" tunable, the ppt_setup_msix() function would fail
and return an error without properly cleaning up. This in turn would
cause a page fault on the next boot of the guest.

Fix this by calling ppt_teardown_msix() in all the error return paths.

Obtained from:	NetApp
2012-11-22 04:07:18 +00:00
Neel Natu
288aeb8561 Get rid of redundant comparision which is guaranteed to be "true" for unsigned
integers.

Obtained from:	NetApp
2012-11-22 00:08:20 +00:00
Peter Grehan
a0cad47092 Handle CPUID leaf 0x7 now that FreeBSD is using it.
Return 0's for now.

Reviewed by:	neel
Obtained from:	NetApp
2012-11-20 06:01:03 +00:00
Peter Grehan
0a5e9bfb72 Fix issue found with clang build. Avoid code insertion by the compiler
between inline asm statements that would in turn modify the flags
value set by the first asm, and used by the second.

Solve by making the common error block a string that can be pulled
into the first inline asm, and using symbolic labels for asm variables.

bhyve can now build/run fine when compiled with clang.

Reviewed by:	neel
Obtained from:	NetApp
2012-11-06 02:43:41 +00:00
Neel Natu
514393f565 Convert VMCS_ENTRY_INTR_INFO field into a vmcs identifier before passing it
to vmcs_getreg(). Without this conversion vmcs_getreg() will return EINVAL.

In particular this prevented injection of the breakpoint exception into the
guest via the "-B" option to /usr/sbin/bhyve which is hugely useful when
debugging guest hangs.

This was broken in r241921.

Pointy hat: me
Obtained from:	NetApp
2012-10-29 23:58:15 +00:00
Neel Natu
b01c203325 Corral all the host state associated with the virtual machine into its own file.
This state is independent of the type of hardware assist used so there is
really no need for it to be in Intel-specific code.

Obtained from:	NetApp
2012-10-29 01:51:24 +00:00
Peter Grehan
cda5bd7f19 Set the valid field of the newly allocated field as all other
vm page allocators do. This fixes a panic when a virtio block
device is mounted as root, with the host system dying in
vm_page_dirty with invalid bits.

Reviewed by:	neel
Obtained from:	NetApp
2012-10-26 22:32:26 +00:00
Neel Natu
bd8572e0be Unconditionally enable fpu emulation by setting CR0.TS in the host after the
guest does a vm exit.

This allows us to trap any fpu access in the host context while the fpu still
has "dirty" state belonging to the guest.

Reported by: "s vas" on freebsd-virtualization@
Obtained from:	NetApp
2012-10-26 03:12:40 +00:00
Neel Natu
f76fc5d414 If the guest vcpu wants to idle then use that opportunity to relinquish the
host cpu to the scheduler until the guest is ready to run again.

This implies that the host cpu utilization will now closely mirror the actual
load imposed by the guest vcpu.

Also, the vcpu mutex now needs to be of type MTX_SPIN since we need to acquire
it inside a critical section.

Obtained from:	NetApp
2012-10-25 04:29:21 +00:00
Neel Natu
ff6ec151e0 Hide the monitor/mwait instruction capability from the guest until we know how
to properly intercept it.

Obtained from:	NetApp
2012-10-25 04:08:26 +00:00
Neel Natu
f352ff0ca8 Maintain state regarding NMI delivery to guest vcpu in VT-x independent manner.
Also add a stats counter to count the number of NMIs delivered per vcpu.

Obtained from:	NetApp
2012-10-24 02:54:21 +00:00
Neel Natu
eeefa4e4be Test for AST pending with interrupts disabled right before entering the guest.
If an IPI was delivered to this cpu before interrupts were disabled
then return right away via vmx_setjmp() with a return value of VMX_RETURN_AST.

Obtained from:	NetApp
2012-10-23 02:20:42 +00:00
Neel Natu
2e25737a49 Calculate the number of host ticks until the next guest timer interrupt.
This information will be used in conjunction with guest "HLT exiting" to
yield the thread hosting the virtual cpu.

Obtained from:	NetApp
2012-10-20 08:23:05 +00:00
Peter Grehan
13ec93719a Add the guest physical address and r/w/x bits to
the paging exit in preparation for a rework of
bhyve MMIO handling.

Reviewed by:	neel
Obtained from:	NetApp
2012-10-12 23:12:19 +00:00
Neel Natu
75dd336603 Provide per-vcpu locks instead of relying on a single big lock.
This also gets rid of all the witness.watch warnings related to calling
malloc(M_WAITOK) while holding a mutex.

Reviewed by:	grehan
2012-10-12 18:32:44 +00:00
Neel Natu
cdc5b9e7b1 Fix warnings generated by 'debug.witness.watch' during VM creation and
destruction for calling malloc() with M_WAITOK while holding a mutex.

Do not allow vmm.ko to be unloaded until all virtual machines are destroyed.
2012-10-11 19:39:54 +00:00
Neel Natu
f9d4f89e4d Deliver the MSI to the correct guest virtual cpu.
Prior to this change the MSI was being delivered unconditionally to vcpu 0
regardless of how the guest programmed the MSI delivery.
2012-10-11 19:28:07 +00:00
Neel Natu
7ce04d0ad9 Allocate memory pages for the guest from the host's free page queue.
It is no longer necessary to hard-partition the memory between the host
and guests at boot time.
2012-10-08 23:41:26 +00:00
Neel Natu
f7d51510f1 Change vm_malloc() to map pages in the guest physical address space in 4KB
chunks. This breaks the assumption that the entire memory segment is
contiguously allocated in the host physical address space.

This also paves the way to satisfy the 4KB page allocations by requesting
free pages from the VM subsystem as opposed to hard-partitioning host memory
at boot time.
2012-10-04 02:27:14 +00:00
Neel Natu
4db4fb2c25 Get rid of assumptions in the hypervisor that the host physical memory
associated with guest physical memory is contiguous.

Add check to vm_gpa2hpa() that the range indicated by [gpa,gpa+len) is all
contained within a single 4KB page.
2012-10-03 01:18:51 +00:00
Neel Natu
bda273f21e Get rid of assumptions in the hypervisor that the host physical memory
associated with guest physical memory is contiguous.

Rewrite vm_gpa2hpa() to get the GPA to HPA mapping by querying the nested
page tables.
2012-10-03 00:46:30 +00:00
Neel Natu
341f19c949 Get rid of assumptions in the hypervisor that the host physical memory
associated with guest physical memory is contiguous.

In this case vm_malloc() was using vm_gpa2hpa() to indirectly infer whether
or not the address range had already been allocated.

Replace this instead with an explicit API 'vm_gpa_available()' that returns
TRUE if a page is available for allocation in guest physical address space.
2012-09-29 01:15:45 +00:00
Neel Natu
70593114cd Intel VT-x provides the length of the instruction at the time of the nested
page table fault. Use this when fetching the instruction bytes from the guest
memory.

Also modify the lapic_mmio() API so that a decoded instruction is fed into it
instead of having it fetch the instruction bytes from the guest. This is
useful for hardware assists like SVM that provide the faulting instruction
as part of the vmexit.
2012-09-27 00:27:58 +00:00
Neel Natu
73820fb0a4 Add an option "-a" to present the local apic in the XAPIC mode instead of the
default X2APIC mode to the guest.
2012-09-26 00:06:17 +00:00
Neel Natu
a2da7af6bc Add support for trapping MMIO writes to local apic registers and emulating them.
The default behavior is still to present the local apic to the guest in the
x2apic mode.
2012-09-25 22:31:35 +00:00
Neel Natu
e90273829b Add ioctls to control the X2APIC capability exposed by the virtual machine to
the guest.

At the moment this simply sets the state in the 'vcpu' instance but there is
no code that acts upon these settings.
2012-09-25 19:08:51 +00:00
Neel Natu
edf89256dd Add an explicit exit code 'SPINUP_AP' to tell the controlling process that an
AP needs to be activated by spinning up an execution context for it.

The local apic emulation is now completely done in the hypervisor and it will
detect writes to the ICR_LO register that try to bring up the AP. In response
to such writes it will return to userspace with an exit code of SPINUP_AP.

Reviewed by: grehan
2012-09-25 02:33:25 +00:00
Neel Natu
98ed632c63 Stash the 'vm_exit' information in each 'struct vcpu'.
There is no functional change at this time but this paves the way for vm exit
handler functions to easily modify the exit reason going forward.
2012-09-24 19:32:24 +00:00
Neel Natu
2d3a73ed6d Restructure the x2apic access code in preparation for supporting memory mapped
access to the local apic.

The vlapic code is now aware of the mode that the guest is using to access the
local apic.

Reviewed by: grehan@
2012-09-21 03:09:23 +00:00
Peter Grehan
177fd53318 Add sysctls to display the total and free amount of hard-wired mem for VMs
# sysctl hw.vmm
   hw.vmm.mem_free: 2145386496
   hw.vmm.mem_total: 2145386496

Submitted by:	Takeshi HASEGAWA hasegaw at gmail com
2012-08-26 01:41:41 +00:00
Neel Natu
39c21c2db2 Force certain bits in %cr4 to be hard-wired to '1' or '0' from a guest's
perspective. If we don't do this some guest OSes (e.g. Linux) will reset
the CR4_VMXE bit in %cr4 with disastrous consequences.

Reported by: grehan
2012-08-04 02:06:55 +00:00