In the past, kvm_get_kvm() and kvm_put_kvm() was called in assigned device irq
handler and interrupt_work, in order to prevent cancel_work_sync() in
kvm_free_assigned_irq got a illegal state when waiting for interrupt_work done.
But it's tricky and still got two problems:

1. A bug ignored two conditions that cancel_work_sync() would return true result
in a additional kvm_put_kvm().

2. If interrupt type is MSI, we would got a window between cancel_work_sync()
and free_irq(), which interrupt would be injected again...

This patch discard the reference count used for irq handler and interrupt_work,
and ensure the legal state by moving the free function at the very beginning of
kvm_destroy_vm(). And the patch fix the second bug by disable irq before
cancel_work_sync(), which may result in nested disable of irq but OK for we are
going to free it.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

kvm_arch_sync_events is introduced to quiet down all other events may happen
contemporary with VM destroy process, like IRQ handler and work struct for
assigned device.

For kvm_arch_sync_events is called at the very beginning of kvm_destroy_vm(), so
the state of KVM here is legal and can provide a environment to quiet down other
events.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

There is no point in doing the ready_for_nmi_injection/
request_nmi_window dance with user space. First, we don't do this for
in-kernel irqchip anyway, while the code path is the same as for user
space irqchip mode. And second, there is nothing to loose if a pending
NMI is overwritten by another one (in contrast to IRQs where we have to
save the number). Actually, there is even the risk of raising spurious
NMIs this way because the reason for the held-back NMI might already be
handled while processing the first one.

Therefore this patch creates a simplified user space NMI injection
interface, exporting it under KVM_CAP_USER_NMI and dropping the old
KVM_CAP_NMI capability. And this time we also take care to provide the
interface only on archs supporting NMIs via KVM (right now only x86).
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NAvi Kivity <avi@redhat.com>

If the guest executes invlpg, peek into the pagetable and attempt to
prepopulate the shadow entry.

Also stop dirty fault updates from interfering with the fork detector.

2% improvement on RHEL3/AIM7.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Skip syncing global pages on cr3 switch (but not on cr4/cr0). This is
important for Linux 32-bit guests with PAE, where the kmap page is
marked as global.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The code to traverse the cpuid data array list for counting type of leaves is
currently broken.

This patches fixes the 2 things in it.

 1. Set the 1st counting entry's flag KVM_CPUID_FLAG_STATE_READ_NEXT. Without
    it the code will never find a valid entry.

 2. Also the stop condition in the for loop while looking for the next unflaged
    entry is broken. It needs to stop when it find one matching entry;
    and in the case of count of 1, it will be the same entry found in this
    iteration.
Signed-Off-By: NNitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

For cpuid leaf 0xb the bits 8-15 in ECX register define the end of counting
leaf.      The previous code was using bits 0-7 for this purpose, which is
a bug.
Signed-off-by: NNitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Ideally, every assigned device should in a clear condition before and after
assignment, so that the former state of device won't affect later work.
Some devices provide a mechanism named Function Level Reset, which is
defined in PCI/PCI-e document. We should execute it before and after device
assignment.

(But sadly, the feature is new, and most device on the market now don't
support it. We are considering using D0/D3hot transmit to emulate it later,
but not that elegant and reliable as FLR itself.)

[Update: Reminded by Xiantao, execute FLR after we ensure that the device can
be assigned to the guest.]
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If we call the emulator we shouldn't call skip_emulated_instruction()
in the first place, since the emulator already computes the next rip
for us. Thus we move ->skip_emulated_instruction() out of
kvm_emulate_pio() and into handle_io() (and the svm equivalent). We
also replaced "return 0" by "break" in the "do_io:" case because now
the shadow register state needs to be committed. Otherwise eip will never
be updated.
Signed-off-by: NGuillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

get_segment_descritptor_dtable() contains an obvious type.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The effective memory type of EPT is the mixture of MSR_IA32_CR_PAT and memory
type field of EPT entry.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

GUEST_PAT support is a new feature introduced by Intel Core i7 architecture.
With this, cpu would save/load guest and host PAT automatically, for EPT memory
type in guest depends on MSR_IA32_CR_PAT.

Also add save/restore for MSR_IA32_CR_PAT.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

As well as reset mmu context when set MTRR.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Call kvm_arch_vcpu_reset() instead of directly using arch callback.
The function does additional things.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Introduces the KVM_NMI IOCTL to the generic x86 part of KVM for
injecting NMIs from user space and also extends the statistic report
accordingly.

Based on the original patch by Sheng Yang.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NSheng Yang <sheng.yang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Ensure that a VCPU with pending NMIs is considered runnable.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

CPU reset invalidates pending or already injected NMIs, therefore reset
the related state variables.

Based on original patch by Gleb Natapov.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Every call of kvm_set_irq() should offer an irq_source_id, which is
allocated by kvm_request_irq_source_id(). Based on irq_source_id, we
identify the irq source and implement logical OR for shared level
interrupts.

The allocated irq_source_id can be freed by kvm_free_irq_source_id().

Currently, we support at most sizeof(unsigned long) different irq sources.

[Amit: - rebase to kvm.git HEAD
       - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file
       - move kvm_request_irq_source_id to the update_irq ioctl]

[Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests]
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To share with other archs, this patch moves device assignment
logic to common parts.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

KVM-x86 dumps a lot of debug messages that have no meaning for normal
operation:
 - INIT de-assertion is ignored
 - SIPIs are sent and received
 - APIC writes are unaligned or < 4 byte long
   (Windows Server 2003 triggers this on SMP)

Degrade them to true debug messages, keeping the host kernel log clean
for real problems.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The PIC code makes little effort to avoid kvm_vcpu_kick(), resulting in
unnecessary guest exits in some conditions.

For example, if the timer interrupt is routed through the IOAPIC, IRR
for IRQ 0 will get set but not cleared, since the APIC is handling the
acks.

This means that everytime an interrupt < 16 is triggered, the priority
logic will find IRQ0 pending and send an IPI to vcpu0 (in case IRQ0 is
not masked, which is Linux's case).

Introduce a new variable isr_ack to represent the IRQ's for which the
guest has been signalled / cleared the ISR. Use it to avoid more than
one IPI per trigger-ack cycle, in addition to the avoidance when ISR is
set in get_priority().
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Allow guest pagetables to go out of sync.  Instead of emulating write
accesses to guest pagetables, or unshadowing them, we un-write-protect
the page table and allow the guest to modify it at will.  We rely on
invlpg executions to synchronize individual ptes, and will synchronize
the entire pagetable on tlb flushes.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

With pages out of sync invlpg needs to be trapped. For now simply nuke
the entry.

Untested on AMD.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The vcpu should process pending SIPI message before entering guest mode again.
kvm_arch_vcpu_runnable() returns true if the vcpu is in SIPI state, so
we can't call it here.
Signed-off-by: NGleb Natapov <gleb@qumranet.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Noticed by sparse:
arch/x86/kvm/x86.c:3591:5: warning: symbol 'kvm_load_realmode_segment' was not declared. Should it be static?
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Convert gfn_to_pfn to use get_user_pages_fast, which can do lockless
pagetable lookups on x86. Kernel compilation on 4-way guest is 3.7%
faster on VMX.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When an IRQ allocation fails, we free up the device structures and
disable the device so that we can unregister the device in the
userspace and not expose it to the guest at all.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Based on a patch by: Kay, Allen M <allen.m.kay@intel.com>

This patch enables PCI device assignment based on VT-d support.
When a device is assigned to the guest, the guest memory is pinned and
the mapping is updated in the VT-d IOMMU.

[Amit: Expose KVM_CAP_IOMMU so we can check if an IOMMU is present
and also control enable/disable from userspace]
Signed-off-by: NKay, Allen M <allen.m.kay@intel.com>
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NBen-Ami Yassour <benami@il.ibm.com>
Signed-off-by: NAmit Shah <amit.shah@qumranet.com>
Acked-by: NMark Gross <mgross@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Since "KVM: x86: do not execute halted vcpus", HLT by vcpu0 before system
reset by the IO thread will hang the guest.

Mark vcpu as runnable in such case.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Offline or uninitialized vcpu's can be executed if requested to perform
userspace work.

Follow Avi's suggestion to handle halted vcpu's in the main loop,
simplifying kvm_emulate_halt(). Introduce a new vcpu->requests bit to
indicate events that promote state from halted to running.

Also standardize vcpu wake sites.

Signed-off-by: Marcelo Tosatti <mtosatti <at> redhat.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

These can help show whether a guest is making progress or not.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Currently KVM implements MC0-MC4_MISC read support. When booting Linux this
results in KVM warnings in the kernel log when the guest tries to read
MC5_MISC. Fix this warnings with this patch.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

There is no reason to share internal memory slots with fork()ed instances.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Real mode segments to not reference the GDT or LDT; they simply compute
base = selector * 16.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

sparse says:

arch/x86/kvm/x86.c:107:32: warning: symbol 'kvm_find_assigned_dev' was not declared. Should it be static?
arch/x86/kvm/i8254.c:225:6: warning: symbol 'kvm_pit_ack_irq' was not declared. Should it be static?
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

... instead of using the pic and ioapic variants
Signed-off-by: NAmit Shah <amit.shah@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>