Previous patch "kvm: Minor memory slot optimization" (b7f69c555c)
overlooked the generation field of the memory slots. Re-using the
original memory slots left us with with two slightly different memory
slots with the same generation. To fix this, make update_memslots()
take a new parameter to specify the last generation. This also makes
generation management more explicit to avoid such problems in the future.
Reported-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
This hack is wrong. The pin number of PIT is connected to
2 not 0. This means this hack never takes effect. So it is ok
to remove it.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
We're currently offering a whopping 32 memory slots to user space, an
int is a bit excessive for storing this. We would like to increase
our memslots, but SHRT_MAX should be more than enough.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
There's no need for this to be an int, it holds a boolean.
Move to the end of the struct for alignment.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
It's easy to confuse KVM_MEMORY_SLOTS and KVM_MEM_SLOTS_NUM. One is
the user accessible slots and the other is user + private. Make this
more obvious.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If a slot is removed or moved in the guest physical address space, we
first allocate and install a new slot array with the invalidated
entry. The old array is then freed. We then proceed to allocate yet
another slot array to install the permanent replacement. Re-use the
original array when this occurs and avoid the extra kfree/kmalloc.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The iommu integration into memory slots expects memory slots to be
added or removed and doesn't handle the move case. We can unmap
slots from the iommu after we mark them invalid and map them before
installing the final memslot array. Also re-order the kmemdup vs
map so we don't leave iommu mappings if we get ENOMEM.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The API documents that only flags and guest physical memory space can
be modified on an existing slot, but we don't enforce that the
userspace address cannot be modified. Instead we just ignore it.
This means that a user may think they've successfully moved both the
guest and user addresses, when in fact only the guest address changed.
Check and error instead.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The API documentation states:
When changing an existing slot, it may be moved in the guest
physical memory space, or its flags may be modified.
An "existing slot" requires a non-zero npages (memory_size). The only
transition we should therefore allow for a non-existing slot should be
to create the slot, which includes setting a non-zero memory_size. We
currently allow calls to modify non-existing slots, which is pointless,
confusing, and possibly wrong.
With this we know that the invalidation path of __kvm_set_memory_region
is always for a delete or move and never for adding a zero size slot.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The current eventfd code assumes that when we have eventfd, we also have
irqfd for in-kernel interrupt delivery. This is not necessarily true. On
PPC we don't have an in-kernel irqchip yet, but we can still support easily
support eventfd.
Signed-off-by: Alexander Graf <agraf@suse.de>
We can deliver certain interrupts, notably MSI,
from atomic context. Use kvm_set_irq_inatomic,
to implement an irq handler for msi.
This reduces the pressure on scheduler in case
where host and guest irq share a host cpu.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Add an API to inject IRQ from atomic context.
Return EWOULDBLOCK if impossible (e.g. for multicast).
Only MSI is supported ATM.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Prior to memory slot sorting this loop compared all of the user memory
slots for overlap with new entries. With memory slot sorting, we're
just checking some number of entries in the array that may or may not
be user slots. Instead, walk all the slots with kvm_for_each_memslot,
which has the added benefit of terminating early when we hit the first
empty slot, and skip comparison to private slots.
Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM added a global variable to guarantee monotonicity in the guest.
One of the reasons for that is that the time between
1. ktime_get_ts(×pec);
2. rdtscll(tsc);
Is variable. That is, given a host with stable TSC, suppose that
two VCPUs read the same time via ktime_get_ts() above.
The time required to execute 2. is not the same on those two instances
executing in different VCPUS (cache misses, interrupts...).
If the TSC value that is used by the host to interpolate when
calculating the monotonic time is the same value used to calculate
the tsc_timestamp value stored in the pvclock data structure, and
a single <system_timestamp, tsc_timestamp> tuple is visible to all
vcpus simultaneously, this problem disappears. See comment on top
of pvclock_update_vm_gtod_copy for details.
Monotonicity is then guaranteed by synchronicity of the host TSCs
and guest TSCs.
Set TSC stable pvclock flag in that case, allowing the guest to read
clock from userspace.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We should avoid kfree()ing error pointer in kvm_vcpu_ioctl() and
kvm_arch_vcpu_ioctl().
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch filters noslot pfn out from error pfns based on Marcelo comment:
noslot pfn is not a error pfn
After this patch,
- is_noslot_pfn indicates that the gfn is not in slot
- is_error_pfn indicates that the gfn is in slot but the error is occurred
when translate the gfn to pfn
- is_error_noslot_pfn indicates that the pfn either it is error pfns or it
is noslot pfn
And is_invalid_pfn can be removed, it makes the code more clean
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Merge reason: development work has dependency on kvm patches merged
upstream.
Conflicts:
arch/powerpc/include/asm/Kbuild
arch/powerpc/include/asm/kvm_para.h
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We can not directly call kvm_release_pfn_clean to release the pfn
since we can meet noslot pfn which is used to cache mmio info into
spte
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
Change existing kernel error message to include return value from
iommu_attach_device() when it fails. This will help debug device
assignment failures more effectively.
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Alex Williamson
Yang Zhang
Marcelo Tosatti
Alexander Graf
Michael S. Tsirkin
Guo Chao
Xiao Guangrong
Linus Torvalds
Shuah Khan
Takuya Yoshikawa