Commit Graph

28 Commits

Author SHA1 Message Date
Andrea Arcangeli
e930bffe95 KVM: Synchronize guest physical memory map to host virtual memory map
Synchronize changes to host virtual addresses which are part of
a KVM memory slot to the KVM shadow mmu.  This allows pte operations
like swapping, page migration, and madvise() to transparently work
with KVM.

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-29 12:33:53 +03:00
Marcelo Tosatti
34d4cb8fca KVM: MMU: nuke shadowed pgtable pages and ptes on memslot destruction
Flush the shadow mmu before removing regions to avoid stale entries.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Laurent Vivier
5f94c1741b KVM: Add coalesced MMIO support (common part)
This patch adds all needed structures to coalesce MMIOs.
Until an architecture uses it, it is not compiled.

Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that
can be coalesced:

- KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone.
  It requests one parameter (struct kvm_coalesced_mmio_zone) which defines
  a memory area where MMIOs can be coalesced until the next switch to
  user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX.

- KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside
  the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone).

The userspace client can check kernel coalesced MMIO availability by asking
ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability.
The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported,
or the page offset where will be stored the ring buffer.
The page offset depends on the architecture.

After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to
a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is
an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively
to the address of the start of th kvm_run structure. The MMIO ring buffer
is defined by the structure kvm_coalesced_mmio_ring.

[akio: fix oops during guest shutdown]

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:31 +03:00
Laurent Vivier
92760499d0 KVM: kvm_io_device: extend in_range() to manage len and write attribute
Modify member in_range() of structure kvm_io_device to pass length and the type
of the I/O (write or read).

This modification allows to use kvm_io_device with coalesced MMIO.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Avi Kivity
7cc8883074 KVM: Remove decache_vcpus_on_cpu() and related callbacks
Obsoleted by the vmx-specific per-cpu list.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Marcelo Tosatti
06e0564566 KVM: close timer injection race window in __vcpu_run
If a timer fires after kvm_inject_pending_timer_irqs() but before
local_irq_disable() the code will enter guest mode and only inject such
timer interrupt the next time an unrelated event causes an exit.

It would be simpler if the timer->pending irq conversion could be done
with IRQ's disabled, so that the above problem cannot happen.

For now introduce a new vcpu requests bit to cancel guest entry.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:16:59 +03:00
Marcelo Tosatti
2f5997140f KVM: migrate PIT timer
Migrate the PIT timer to the physical CPU which vcpu0 is scheduled on,
similarly to what is done for the LAPIC timers, otherwise PIT interrupts
will be delayed until an unrelated event causes an exit.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:25:51 +03:00
Al Viro
66c0b394f0 KVM: kill file->f_count abuse in kvm
Use kvm own refcounting instead of playing with ->filp->f_count.
That will allow to get rid of a lot of crap in anon_inode_getfd() and
kill a race in kvm_dev_ioctl_create_vm() (file might have been closed
immediately by another thread, so ->filp might point to already freed
struct file when we get around to setting it).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 18:21:46 +03:00
Hollis Blanchard
76f7c87902 KVM: Rename debugfs_dir to kvm_debugfs_dir
It's a globally exported symbol now.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 18:21:36 +03:00
Marcelo Tosatti
62d9f0dbc9 KVM: add ioctls to save/store mpstate
So userspace can save/restore the mpstate during migration.

[avi: export the #define constants describing the value]
[christian: add s390 stubs]
[avi: ditto for ia64]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 18:21:16 +03:00
Marcelo Tosatti
3d80840d96 KVM: hlt emulation should take in-kernel APIC/PIT timers into account
Timers that fire between guest hlt and vcpu_block's add_wait_queue() are
ignored, possibly resulting in hangs.

Also make sure that atomic_inc and waitqueue_active tests happen in the
specified order, otherwise the following race is open:

CPU0                                        CPU1
                                            if (waitqueue_active(wq))
add_wait_queue()
if (!atomic_read(pit_timer->pending))
    schedule()
                                            atomic_inc(pit_timer->pending)

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:04:11 +03:00
Feng(Eric) Liu
d4c9ff2d1b KVM: Add kvm trace userspace interface
This interface allows user a space application to read the trace of kvm
related events through relayfs.

Signed-off-by: Feng (Eric) Liu <eric.e.liu@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:01:22 +03:00
Anthony Liguori
35149e2129 KVM: MMU: Don't assume struct page for x86
This patch introduces a gfn_to_pfn() function and corresponding functions like
kvm_release_pfn_dirty().  Using these new functions, we can modify the x86
MMU to no longer assume that it can always get a struct page for any given gfn.

We don't want to eliminate gfn_to_page() entirely because a number of places
assume they can do gfn_to_page() and then kmap() the results.  When we support
IO memory, gfn_to_page() will fail for IO pages although gfn_to_pfn() will
succeed.

This does not implement support for avoiding reference counting for reserved
RAM or for IO memory.  However, it should make those things pretty straight
forward.

Since we're only introducing new common symbols, I don't think it will break
the non-x86 architectures but I haven't tested those.  I've tested Intel,
AMD, NPT, and hugetlbfs with Windows and Linux guests.

[avi: fix overflow when shifting left pfns by adding casts]

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:01:15 +03:00
Izik Eidus
d39f13b0da KVM: add vm refcounting
the main purpose of adding this functions is the abilaty to release the
spinlock that protect the kvm list while still be able to do operations
on a specific kvm in a safe way.

Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:56 +03:00
Avi Kivity
69a9f69bb2 KVM: Move some x86 specific constants and structures to include/asm-x86
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:34 +03:00
Joerg Roedel
71c4dfafc0 KVM: detect if VCPU triple faults
In the current inject_page_fault path KVM only checks if there is another PF
pending and injects a DF then. But it has to check for a pending DF too to
detect a shutdown condition in the VCPU.  If this is not detected the VCPU goes
to a PF -> DF -> PF loop when it should triple fault. This patch detects this
condition and handles it with an KVM_SHUTDOWN exit to userspace.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 11:53:27 +03:00
Marcelo Tosatti
05da45583d KVM: MMU: large page support
Create large pages mappings if the guest PTE's are marked as such and
the underlying memory is hugetlbfs backed.  If the largepage contains
write-protected pages, a large pte is not used.

Gives a consistent 2% improvement for data copies on ram mounted
filesystem, without NPT/EPT.

Anthony measures a 4% improvement on 4-way kernbench, with NPT.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 11:53:25 +03:00
Marcelo Tosatti
2e53d63acb KVM: MMU: ignore zapped root pagetables
Mark zapped root pagetables as invalid and ignore such pages during lookup.

This is a problem with the cr3-target feature, where a zapped root table fools
the faulting code into creating a read-only mapping. The result is a lockup
if the instruction can't be emulated.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 11:53:25 +03:00
Avi Kivity
ef2979bd98 KVM: Increase the number of user memory slots per vm
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 11:53:23 +03:00
Avi Kivity
edbe6c325d KVM: Increase vcpu count to 16
With NPT support, scalability is much improved.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 11:53:23 +03:00
Hollis Blanchard
31bb117eb4 KVM: Use CONFIG_PREEMPT_NOTIFIERS around struct preempt_notifier
This allows kvm_host.h to be #included even when struct preempt_notifier is
undefined. This is needed to build ppc asm-offsets.h.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 11:53:18 +03:00
Izik Eidus
72dc67a696 KVM: remove the usage of the mmap_sem for the protection of the memory slots.
This patch replaces the mmap_sem lock for the memory slots with a new
kvm private lock, it is needed beacuse untill now there were cases where
kvm accesses user memory while holding the mmap semaphore.

Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-04 15:19:40 +02:00
Avi Kivity
2f52d58c92 KVM: Move apic timer migration away from critical section
Migrating the apic timer in the critical section is not very nice, and is
absolutely horrible with the real-time port.  Move migration to the regular
vcpu execution path, triggered by a new bitflag.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30 18:01:22 +02:00
Marcelo Tosatti
aaee2c94f7 KVM: MMU: Switch to mmu spinlock
Convert the synchronization of the shadow handling to a separate mmu_lock
spinlock.

Also guard fetch() by mmap_sem in read-mode to protect against alias
and memslot changes.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30 18:01:21 +02:00
Marcelo Tosatti
7ec5458821 KVM: Add kvm_read_guest_atomic()
In preparation for a mmu spinlock, add kvm_read_guest_atomic()
and use it in fetch() and prefetch_page().

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30 18:01:20 +02:00
Avi Kivity
b209749f52 KVM: local APIC TPR access reporting facility
Add a facility to report on accesses to the local apic tpr even if the
local apic is emulated in the kernel.  This is basically a hack that
allows userspace to patch Windows which tends to bang on the tpr a lot.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30 18:01:20 +02:00
Zhang Xiantao
5736199afb KVM: Move kvm_vcpu_kick() to x86.c
Moving kvm_vcpu_kick() to x86.c. Since it should be
common for all archs, put its declarations in <linux/kvm_host.h>

Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30 18:01:19 +02:00
Avi Kivity
edf884172e KVM: Move arch dependent files to new directory arch/x86/kvm/
This paves the way for multiple architecture support.  Note that while
ioapic.c could potentially be shared with ia64, it is also moved.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30 18:01:18 +02:00