linux-toradex.git/include/linux/kvm_host.h, branch v4.5-rc2

kvm: rename pfn_t to kvm_pfn_t

2016-01-16T01:56:32+00:00

To date, we have implemented two I/O usage models for persistent memory,
PMEM (a persistent "ram disk") and DAX (mmap persistent memory into
userspace).  This series adds a third, DAX-GUP, that allows DAX mappings
to be the target of direct-i/o.  It allows userspace to coordinate
DMA/RDMA from/to persistent memory.

The implementation leverages the ZONE_DEVICE mm-zone that went into
4.3-rc1 (also discussed at kernel summit) to flag pages that are owned
and dynamically mapped by a device driver.  The pmem driver, after
mapping a persistent memory range into the system memmap via
devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus
page-backed pmem-pfns via flags in the new pfn_t type.

The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the
resulting pte(s) inserted into the process page tables with a new
_PAGE_DEVMAP flag.  Later, when get_user_pages() is walking ptes it keys
off _PAGE_DEVMAP to pin the device hosting the page range active.
Finally, get_page() and put_page() are modified to take references
against the device driver established page mapping.

Finally, this need for "struct page" for persistent memory requires
memory capacity to store the memmap array.  Given the memmap array for a
large pool of persistent may exhaust available DRAM introduce a
mechanism to allocate the memmap from persistent memory.  The new
"struct vmem_altmap *" parameter to devm_memremap_pages() enables
arch_add_memory() to use reserved pmem capacity rather than the page
allocator.

This patch (of 18):

The core has developed a need for a "pfn_t" type [1].  Move the existing
pfn_t in KVM to kvm_pfn_t [2].

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html

Signed-off-by: Dan Williams 
Acked-by: Christoffer Dall 
Cc: Paolo Bonzini 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

KVM: move architecture-dependent requests to arch/

2016-01-08T18:04:36+00:00

Since the numbers now overlap, it makes sense to enumerate
them in asm/kvm_host.h rather than linux/kvm_host.h.  Functions
that refer to architecture-specific requests are also moved
to arch/.

Signed-off-by: Paolo Bonzini

KVM: renumber vcpu->request bits

2016-01-08T18:03:06+00:00

Leave room for 4 more arch-independent requests.

Reviewed-by: Christian Borntraeger 
Signed-off-by: Paolo Bonzini

KVM: document which architecture uses each request bit

2016-01-08T18:03:06+00:00

Reviewed-by: Christian Borntraeger 
Signed-off-by: Paolo Bonzini

KVM: Remove unused KVM_REQ_KICK to save a bit in vcpu->requests

2016-01-08T18:03:05+00:00

Suggested-by: Takuya Yoshikawa 
[Takuya moved all subsequent constants to fill the void, but that
 is useless in view of the following patches.  So this change looks
 nothing like the original. - Paolo]
Reviewed-by: Christian Borntraeger 
Signed-off-by: Paolo Bonzini

kvm: Dump guest rIP when the guest tried something unsupported

2015-12-16T17:49:48+00:00

It looks like this in action:

  kvm [5197]: vcpu0, guest rIP: 0xffffffff810187ba unhandled rdmsr: 0xc001102

and helps to pinpoint quickly where in the guest we did the unsupported
thing.

Signed-off-by: Borislav Petkov 
Signed-off-by: Paolo Bonzini

kvm/x86: Hyper-V SynIC timers

2015-12-16T17:49:45+00:00

Per Hyper-V specification (and as required by Hyper-V-aware guests),
SynIC provides 4 per-vCPU timers.  Each timer is programmed via a pair
of MSRs, and signals expiration by delivering a special format message
to the configured SynIC message slot and triggering the corresponding
synthetic interrupt.

Note: as implemented by this patch, all periodic timers are "lazy"
(i.e. if the vCPU wasn't scheduled for more than the timer period the
timer events are lost), regardless of the corresponding configuration
MSR.  If deemed necessary, the "catch up" mode (the timer period is
shortened until the timer catches up) will be implemented later.

Changes v2:
* Use remainder to calculate periodic timer expiration time

Signed-off-by: Andrey Smetanin 
Reviewed-by: Roman Kagan 
CC: Gleb Natapov 
CC: Paolo Bonzini 
CC: "K. Y. Srinivasan" 
CC: Haiyang Zhang 
CC: Vitaly Kuznetsov 
CC: Roman Kagan 
CC: Denis V. Lunev 
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini

kvm/x86: Hyper-V SynIC message slot pending clearing at SINT ack

2015-12-16T17:49:44+00:00

The SynIC message protocol mandates that the message slot is claimed
by atomically setting message type to something other than HVMSG_NONE.
If another message is to be delivered while the slot is still busy,
message pending flag is asserted to indicate to the guest that the
hypervisor wants to be notified when the slot is released.

To make sure the protocol works regardless of where the message
sources are (kernel or userspace), clear the pending flag on SINT ACK
notification, and let the message sources compete for the slot again.

Signed-off-by: Andrey Smetanin 
Reviewed-by: Roman Kagan 
CC: Gleb Natapov 
CC: Paolo Bonzini 
CC: "K. Y. Srinivasan" 
CC: Haiyang Zhang 
CC: Vitaly Kuznetsov 
CC: Roman Kagan 
CC: Denis V. Lunev 
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini

KVM: Remove unnecessary debugfs dentry references

2015-11-30T11:47:05+00:00

KVM creates debugfs files to export VM statistics to userland. To be
able to remove them on kvm exit it tracks the files' dentries.

Since their parent directory is also tracked and since each parent
direntry knows its children we can easily remove them by using
debugfs_remove_recursive(kvm_debugfs_dir). Therefore we don't
need the extra tracking in the kvm_stats_debugfs_item anymore.

Signed-off-by: Janosch Frank 
Reviewed-By: Sascha Silbe 
Acked-by: Christian Borntraeger 
Signed-off-by: Christian Borntraeger

KVM: use heuristic for fast VCPU lookup by id

2015-11-30T11:47:04+00:00

Usually, VCPU ids match the array index. So let's try a fast
lookup first before falling back to the slow iteration.

Suggested-by: Christian Borntraeger 
Reviewed-by: Dominik Dingel 
Reviewed-by: Christian Borntraeger 
Signed-off-by: David Hildenbrand 
Signed-off-by: Christian Borntraeger