Avi Kivity [Thu, 2 Dec 2010 15:55:23 +0000 (17:55 +0200)]
KVM: VMX: Return 0 from a failed VMREAD
If we execute VMREAD during reboot we'll just skip over it. Instead of
returning garbage, return 0, which has a much smaller chance of confusing
the code. Otherwise we risk a flood of debug printk()s which block the
reboot process if a serial console or netconsole is enabled.
Avi Kivity [Thu, 2 Dec 2010 15:52:50 +0000 (17:52 +0200)]
KVM: Don't spin on virt instruction faults during reboot
Since vmx blocks INIT signals, we disable virtualization extensions during
reboot. This leads to virtualization instructions faulting; we trap these
faults and spin while the reboot continues.
Unfortunately spinning on a non-preemptible kernel may block a task that
reboot depends on; this causes the reboot to hang.
Fix by skipping over the instruction and hoping for the best.
Joerg Roedel [Tue, 30 Nov 2010 17:04:00 +0000 (18:04 +0100)]
KVM: SVM: Add manipulation functions for misc intercepts
This patch wraps changes to the misc intercepts of SVM
into seperate functions to abstract nested-svm better and
prepare the implementation of the vmcb-clean-bits feature.
Joerg Roedel [Tue, 30 Nov 2010 17:03:59 +0000 (18:03 +0100)]
KVM: SVM: Add manipulation functions for exception intercepts
This patch wraps changes to the exception intercepts of SVM
into seperate functions to abstract nested-svm better and
prepare the implementation of the vmcb-clean-bits feature.
Joerg Roedel [Tue, 30 Nov 2010 17:03:58 +0000 (18:03 +0100)]
KVM: SVM: Add manipulation functions for DRx intercepts
This patch wraps changes to the DRx intercepts of SVM into
seperate functions to abstract nested-svm better and prepare
the implementation of the vmcb-clean-bits feature.
Roedel, Joerg [Fri, 3 Dec 2010 09:50:51 +0000 (10:50 +0100)]
KVM: SVM: Add manipulation functions for CRx intercepts
This patch wraps changes to the CRx intercepts of SVM into
seperate functions to abstract nested-svm better and prepare
the implementation of the vmcb-clean-bits feature.
Joerg Roedel [Tue, 30 Nov 2010 17:03:56 +0000 (18:03 +0100)]
KVM: SVM: Add function to recalculate intercept masks
This patch adds a function to recalculate the effective
intercepts masks when the vcpu is in guest-mode and either
the host or the guest intercept masks change.
Joerg Roedel [Mon, 29 Nov 2010 16:51:49 +0000 (17:51 +0100)]
KVM: X86: Don't report L2 emulation failures to user-space
This patch prevents that emulation failures which result
from emulating an instruction for an L2-Guest results in
being reported to userspace.
Without this patch a malicious L2-Guest would be able to
kill the L1 by triggering a race-condition between an vmexit
and the instruction emulator.
With this patch the L2 will most likely only kill itself in
this situation.
This patch introduces a generic representation of guest-mode
fpr a vcpu. This currently only exists in the SVM code.
Having this representation generic will help making the
non-svm code aware of nesting when this is necessary.
Avi Kivity [Mon, 29 Nov 2010 14:12:30 +0000 (16:12 +0200)]
KVM: Pull extra page fault information into struct x86_exception
Currently page fault cr2 and nesting infomation are carried outside
the fault data structure. Instead they are placed in the vcpu struct,
which results in confusion as global variables are manipulated instead
of passing parameters.
Fix this issue by adding address and nested fields to struct x86_exception,
so this struct can carry all information associated with a fault.
Xiao Guangrong [Tue, 23 Nov 2010 03:13:00 +0000 (11:13 +0800)]
KVM: MMU: delay flush all tlbs on sync_page path
Quote from Avi:
| I don't think we need to flush immediately; set a "tlb dirty" bit somewhere
| that is cleareded when we flush the tlb. kvm_mmu_notifier_invalidate_page()
| can consult the bit and force a flush if set.
Avi Kivity [Thu, 18 Nov 2010 11:09:54 +0000 (13:09 +0200)]
KVM: Add instruction-set-specific exit qualifications to kvm_exit trace
The exit reason alone is insufficient to understand exactly why an exit
occured; add ISA-specific trace parameters for additional information.
Because fetching these parameters is expensive on vmx, and because these
parameters are fetched even if tracing is disabled, we fetch the
parameters via a callback instead of as traditional trace arguments.
Store irq routing table pointer in the irqfd object,
and use that to inject MSI directly without bouncing out to
a kernel thread.
While we touch this structure, rearrange irqfd fields to make fastpath
better packed for better cache utilization.
This also adds some comments about locking rules and rcu usage in code.
Some notes on the design:
- Use pointer into the rt instead of copying an entry,
to make it possible to use rcu, thus side-stepping
locking complexities. We also save some memory this way.
- Old workqueue code is still used for level irqs.
I don't think we DTRT with level anyway, however,
it seems easier to keep the code around as
it has been thought through and debugged, and fix level later than
rip out and re-instate it later.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Acked-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Thu, 18 Nov 2010 11:12:52 +0000 (13:12 +0200)]
KVM: VMX: Fold __vmx_vcpu_run() into vmx_vcpu_run()
cea15c2 ("KVM: Move KVM context switch into own function") split vmx_vcpu_run()
to prevent multiple copies of the context switch from being generated (causing
problems due to a label). This patch folds them back together again and adds
the __noclone attribute to prevent the label from being duplicated.
Avi Kivity [Wed, 17 Nov 2010 13:28:21 +0000 (15:28 +0200)]
KVM: x86 emulator: preserve an operand's segment identity
Currently the x86 emulator converts the segment register associated with
an operand into a segment base which is added into the operand address.
This loss of information results in us not doing segment limit checks properly.
Replace struct operand's addr.mem field by a segmented_address structure
which holds both the effetive address and segment. This will allow us to
do the limit check at the point of access.
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Shane Wang [Wed, 17 Nov 2010 03:40:17 +0000 (11:40 +0800)]
KVM: VMX: Inform user about INTEL_TXT dependency
Inform user to either disable TXT in the BIOS or do TXT launch
with tboot before enabling KVM since some BIOSes do not set
FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX bit when TXT is enabled.
Signed-off-by: Shane Wang <shane.wang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Takuya Yoshikawa [Tue, 16 Nov 2010 08:37:41 +0000 (17:37 +0900)]
KVM: rename hardware_[dis|en]able() to *_nolock() and add locking wrappers
The naming convension of hardware_[dis|en]able family is little bit confusing
because only hardware_[dis|en]able_all are using _nolock suffix.
Renaming current hardware_[dis|en]able() to *_nolock() and using
hardware_[dis|en]able() as wrapper functions which take kvm_lock for them
reduces extra confusion.
Jan Kiszka [Tue, 16 Nov 2010 21:30:07 +0000 (22:30 +0100)]
KVM: Document device assigment API
Adds API documentation for KVM_[DE]ASSIGN_PCI_DEVICE,
KVM_[DE]ASSIGN_DEV_IRQ, KVM_SET_GSI_ROUTING, KVM_ASSIGN_SET_MSIX_NR, and
KVM_ASSIGN_SET_MSIX_ENTRY.
Acked-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Jan Kiszka [Tue, 16 Nov 2010 21:30:06 +0000 (22:30 +0100)]
KVM: Clean up kvm_vm_ioctl_assigned_device
Any arch not supporting device assigment will also not build
assigned-dev.c. So testing for KVM_CAP_DEVICE_DEASSIGNMENT is pointless.
KVM_CAP_ASSIGN_DEV_IRQ is unconditinally set. Moreover, add a default
case for dispatching the ioctl.
Acked-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Jan Kiszka [Tue, 16 Nov 2010 21:30:05 +0000 (22:30 +0100)]
KVM: Save/restore state of assigned PCI device
The guest may change states that pci_reset_function does not touch. So
we better save/restore the assigned device across guest usage.
Acked-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Jan Kiszka [Tue, 16 Nov 2010 21:30:04 +0000 (22:30 +0100)]
KVM: Refactor IRQ names of assigned devices
Cosmetic change, but it helps to correlate IRQs with PCI devices.
Acked-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Jan Kiszka [Tue, 16 Nov 2010 21:30:03 +0000 (22:30 +0100)]
KVM: Switch assigned device IRQ forwarding to threaded handler
This improves the IRQ forwarding for assigned devices: By using the
kernel's threaded IRQ scheme, we can get rid of the latency-prone work
queue and simplify the code in the same run.
Moreover, we no longer have to hold assigned_dev_lock while raising the
guest IRQ, which can be a lenghty operation as we may have to iterate
over all VCPUs. The lock is now only used for synchronizing masking vs.
unmasking of INTx-type IRQs, thus is renames to intx_lock.
Acked-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Jan Kiszka [Tue, 16 Nov 2010 21:30:02 +0000 (22:30 +0100)]
KVM: Clear assigned guest IRQ on release
When we deassign a guest IRQ, clear the potentially asserted guest line.
There might be no chance for the guest to do this, specifically if we
switch from INTx to MSI mode.
Acked-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Avi Kivity [Tue, 9 Nov 2010 14:15:42 +0000 (16:15 +0200)]
KVM: SVM: Replace svm_has() by standard Linux cpuid accessors
Instead of querying cpuid directly, use the Linux accessors (boot_cpu_has,
etc.). This allows the things like the clearcpuid kernel command line to
work (when it's fixed wrt scattered cpuid bits).
Jan Kiszka [Tue, 9 Nov 2010 16:02:49 +0000 (17:02 +0100)]
KVM: Clean up vm creation and release
IA64 support forces us to abstract the allocation of the kvm structure.
But instead of mixing this up with arch-specific initialization and
doing the same on destruction, split both steps. This allows to move
generic destruction calls into generic code.
It also fixes error clean-up on failures of kvm_create_vm for IA64.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Mon, 1 Nov 2010 21:20:48 +0000 (23:20 +0200)]
KVM: VMX: Disallow NMI while blocked by STI
While not mandated by the spec, Linux relies on NMI being blocked by an
IF-enabling STI. VMX also refuses to enter a guest in this state, at
least on some implementations.
Disallow NMI while blocked by STI by checking for the condition, and
requesting an interrupt window exit if it occurs.
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Xiao Guangrong [Mon, 1 Nov 2010 09:03:44 +0000 (17:03 +0800)]
KVM: fix the race while wakeup all pv guest
In kvm_async_pf_wakeup_all(), we add a dummy apf to vcpu->async_pf.done
without holding vcpu->async_pf.lock, it will break if we are handling apfs
at this time.
Also use 'list_empty_careful()' instead of 'list_empty()'
Xiao Guangrong [Mon, 1 Nov 2010 09:01:28 +0000 (17:01 +0800)]
KVM: avoid unnecessary wait for a async pf
In current code, it checks async pf completion out of the wait context,
like this:
if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
!vcpu->arch.apf.halted)
r = vcpu_enter_guest(vcpu);
else {
......
kvm_vcpu_block(vcpu)
^- waiting until 'async_pf.done' is not empty
}
kvm_check_async_pf_completion(vcpu)
^- delete list from async_pf.done
So, if we check aysnc pf completion first, it can be blocked at
kvm_vcpu_block
Fixed by mark the vcpu is unhalted in kvm_check_async_pf_completion()
path
Gleb Natapov [Mon, 1 Nov 2010 13:35:01 +0000 (15:35 +0200)]
KVM: handle exit due to INVD in VMX
Currently the exit is unhandled, so guest halts with error if it tries
to execute INVD instruction. Call into emulator when INVD instruction
is executed by a guest instead. This instruction is not needed by ordinary
guests, but firmware (like OpenBIOS) use it and fail.
Jan Kiszka [Mon, 1 Nov 2010 13:01:29 +0000 (14:01 +0100)]
KVM: x86: Avoid issuing wbinvd twice
Micro optimization to avoid calling wbinvd twice on the CPU that has to
emulate it. As we might be preempted between smp_call_function_many and
the local wbinvd, the cache might be filled again so that real work
could be done uselessly.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Heiko Carstens [Wed, 27 Oct 2010 15:22:10 +0000 (17:22 +0200)]
KVM: get rid of warning within kvm_dev_ioctl_create_vm
Fixes this:
CC arch/s390/kvm/../../../virt/kvm/kvm_main.o
arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function 'kvm_dev_ioctl_create_vm':
arch/s390/kvm/../../../virt/kvm/kvm_main.c:1828:10: warning: unused variable 'r'
Heiko Carstens [Wed, 27 Oct 2010 15:21:21 +0000 (17:21 +0200)]
KVM: add cast within kvm_clear_guest_page to fix warning
Fixes this:
CC arch/s390/kvm/../../../virt/kvm/kvm_main.o
arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function 'kvm_clear_guest_page':
arch/s390/kvm/../../../virt/kvm/kvm_main.c:1224:2: warning: passing argument 3 of 'kvm_write_guest_page' makes pointer from integer without a cast
arch/s390/kvm/../../../virt/kvm/kvm_main.c:1185:5: note: expected 'const void *' but argument is of type 'long unsigned int'
Takuya Yoshikawa [Wed, 27 Oct 2010 09:23:54 +0000 (18:23 +0900)]
KVM: pre-allocate one more dirty bitmap to avoid vmalloc()
Currently x86's kvm_vm_ioctl_get_dirty_log() needs to allocate a bitmap by
vmalloc() which will be used in the next logging and this has been causing
bad effect to VGA and live-migration: vmalloc() consumes extra systime,
triggers tlb flush, etc.
This patch resolves this issue by pre-allocating one more bitmap and switching
between two bitmaps during dirty logging.
Performance improvement:
I measured performance for the case of VGA update by trace-cmd.
The result was 1.5 times faster than the original one.
In the case of live migration, the improvement ratio depends on the workload
and the guest memory size. In general, the larger the memory size is the more
benefits we get.
Note:
This does not change other architectures's logic but the allocation size
becomes twice. This will increase the actual memory consumption only when
the new size changes the number of pages allocated by vmalloc().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Takuya Yoshikawa [Wed, 27 Oct 2010 09:22:19 +0000 (18:22 +0900)]
KVM: introduce wrapper functions for creating/destroying dirty bitmaps
This makes it easy to change the way of allocating/freeing dirty bitmaps.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Avi Kivity [Mon, 25 Oct 2010 13:23:55 +0000 (15:23 +0200)]
KVM: Avoid double interrupt injection with vapic
After an interrupt injection, the PPR changes, and we have to reflect that
into the vapic. This causes a KVM_REQ_EVENT to be set, which causes the
whole interrupt injection routine to be run again (harmlessly).
Optimize by only setting KVM_REQ_EVENT if the ppr was lowered; otherwise
there is no chance that a new injection is needed.
Avi Kivity [Thu, 21 Oct 2010 10:20:33 +0000 (12:20 +0200)]
KVM: SVM: Move fs/gs/ldt save/restore to heavyweight exit path
ldt is never used in the kernel context; same goes for fs (x86_64) and gs
(i386). So save/restore them in the heavyweight exit path instead
of the lightweight path.
By itself, this doesn't buy us much, but it paves the way for moving vmload
and vmsave to the heavyweight exit path, since they modify the same registers.
[jan: fix copy/pase mistake on i386]
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Avi Kivity [Thu, 21 Oct 2010 10:20:31 +0000 (12:20 +0200)]
KVM: SVM: Move guest register save out of interrupts disabled section
Saving guest registers is just a memory copy, and does not need to be in the
critical section. Move outside the critical section to improve latency a
bit.
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Andi Kleen [Wed, 20 Oct 2010 15:56:17 +0000 (17:56 +0200)]
KVM: Move KVM context switch into own function
gcc 4.5 with some special options is able to duplicate the VMX
context switch asm in vmx_vcpu_run(). This results in a compile error
because the inline asm sequence uses an on local label. The non local
label is needed because other code wants to set up the return address.
This patch moves the asm code into an own function and marks
that explicitely noinline to avoid this problem.
Better would be probably to just move it into an .S file.
The diff looks worse than the change really is, it's all just
code movement and no logic change.
Gleb Natapov [Thu, 14 Oct 2010 09:22:55 +0000 (11:22 +0200)]
KVM: Let host know whether the guest can handle async PF in non-userspace context.
If guest can detect that it runs in non-preemptable context it can
handle async PFs at any time, so let host know that it can send async
PF even if guest cpu is not in userspace.
Gleb Natapov [Thu, 14 Oct 2010 09:22:54 +0000 (11:22 +0200)]
KVM paravirt: Handle async PF in non preemptable context
If async page fault is received by idle task or when preemp_count is
not zero guest cannot reschedule, so do sti; hlt and wait for page to be
ready. vcpu can still process interrupts while it waits for the page to
be ready.
Gleb Natapov [Thu, 14 Oct 2010 09:22:53 +0000 (11:22 +0200)]
KVM: Inject asynchronous page fault into a PV guest if page is swapped out.
Send async page fault to a PV guest if it accesses swapped out memory.
Guest will choose another task to run upon receiving the fault.
Allow async page fault injection only when guest is in user mode since
otherwise guest may be in non-sleepable context and will not be able
to reschedule.
Vcpu will be halted if guest will fault on the same page again or if
vcpu executes kernel code.
Gleb Natapov [Thu, 14 Oct 2010 09:22:52 +0000 (11:22 +0200)]
KVM: Handle async PF in a guest.
When async PF capability is detected hook up special page fault handler
that will handle async page fault events and bypass other page faults to
regular page fault handler. Also add async PF handling to nested SVM
emulation. Async PF always generates exit to L1 where vcpu thread will
be scheduled out until page is available.
Gleb Natapov [Mon, 18 Oct 2010 13:22:23 +0000 (15:22 +0200)]
KVM: Add memory slot versioning and use it to provide fast guest write interface
Keep track of memslots changes by keeping generation number in memslots
structure. Provide kvm_write_guest_cached() function that skips
gfn_to_hva() translation if memslots was not changed since previous
invocation.
Gleb Natapov [Sun, 17 Oct 2010 16:13:42 +0000 (18:13 +0200)]
KVM: Retry fault before vmentry
When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.
Gleb Natapov [Thu, 14 Oct 2010 09:22:46 +0000 (11:22 +0200)]
KVM: Halt vcpu if page it tries to access is swapped out
If a guest accesses swapped out memory do not swap it in from vcpu thread
context. Schedule work to do swapping and put vcpu into halted state
instead.
Interrupts will still be delivered to the guest and if interrupt will
cause reschedule guest will continue to run another task.
[avi: remove call to get_user_pages_noio(), nacked by Linus; this
makes everything synchrnous again]
Avi Kivity [Fri, 31 Dec 2010 08:52:15 +0000 (10:52 +0200)]
KVM: i8259: initialize isr_ack
isr_ack is never initialized. So, until the first PIC reset, interrupts
may fail to be injected. This can cause Windows XP to fail to boot, as
reported in the fallout from the fix to
https://bugzilla.kernel.org/show_bug.cgi?id=21962.
Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity [Tue, 28 Dec 2010 10:09:07 +0000 (12:09 +0200)]
KVM: MMU: Fix incorrect direct gfn for unpaged mode shadow
We use the physical address instead of the base gfn for the four
PAE page directories we use in unpaged mode. When the guest accesses
an address above 1GB that is backed by a large host page, a BUG_ON()
in kvm_mmu_set_gfn() triggers.
Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=21962 Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com>
KVM-Stable-Tag. Signed-off-by: Avi Kivity <avi@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: handle rt_sigreturn() more cleanly
arch/tile: handle CLONE_SETTLS in copy_thread(), not user space
projects / linux-beck.git / log