At present, our implementation of H_ENTER only makes one try at locking
each slot that it looks at, and doesn't even retry the ldarx/stdcx.
atomic update sequence that it uses to attempt to lock the slot. Thus
it can return the H_PTEG_FULL error unnecessarily, particularly when
the H_EXACT flag is set, meaning that the caller wants a specific PTEG
slot.
This improves the situation by making a second pass when no free HPTE
slot is found, where we spin until we succeed in locking each slot in
turn and then check whether it is full while we hold the lock. If the
second pass fails, then we return H_PTEG_FULL.
This also moves lock_hpte to a header file (since later commits in this
series will need to use it from other source files) and renames it to
try_lock_hpte, which is a somewhat less misleading name.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This adds two new functions, kvmppc_pin_guest_page() and
kvmppc_unpin_guest_page(), and uses them to pin the guest pages where
the guest has registered areas of memory for the hypervisor to update,
(i.e. the per-cpu virtual processor areas, SLB shadow buffers and
dispatch trace logs) and then unpin them when they are no longer
required.
Although it is not strictly necessary to pin the pages at this point,
since all guest pages are already pinned, later commits in this series
will mean that guest pages aren't all pinned.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This allocates an array for each memory slot that is added to store
the physical addresses of the pages in the slot. This array is
vmalloc'd and accessed in kvmppc_h_enter using real_vmalloc_addr().
This allows us to remove the ram_pginfo field from the kvm_arch
struct, and removes the 64GB guest RAM limit that we had.
We use the low-order bits of the array entries to store a flag
indicating that we have done get_page on the corresponding page,
and therefore need to call put_page when we are finished with the
page. Currently this is set for all pages except those in our
special RMO regions.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This adds an array that parallels the guest hashed page table (HPT),
that is, it has one entry per HPTE, used to store the guest's view
of the second doubleword of the corresponding HPTE. The first
doubleword in the HPTE is the same as the guest's idea of it, so we
don't need to store a copy, but the second doubleword in the HPTE has
the real page number rather than the guest's logical page number.
This allows us to remove the back_translate() and reverse_xlate()
functions.
This "reverse mapping" array is vmalloc'd, meaning that to access it
in real mode we have to walk the kernel's page tables explicitly.
That is done by the new real_vmalloc_addr() function. (In fact this
returns an address in the linear mapping, so the result is usable
both in real mode and in virtual mode.)
There are also some minor cleanups here: moving the definitions of
HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When commit f43fdc15fa ("KVM: PPC: booke: Improve timer register
emulation") factored out some code in arch/powerpc/kvm/powerpc.c
into a new helper function, kvm_vcpu_kick(), an error crept in
which causes Book3s HV guest vcpus to stall. This fixes it.
On POWER7 machines, guest vcpus are grouped together into virtual
CPU cores that share a single waitqueue, so it's important to use
vcpu->arch.wqp rather than &vcpu->wq.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently we patch the whole code include paravirt template code.
This isn't safe for scratch area and has impact to performance.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The hardware maintains a per-set next victim hint. Using this
reduces conflicts, especially on e500v2 where a single guest
TLB entry is mapped to two shadow TLB entries (user and kernel).
We want those two entries to go to different TLB ways.
sesel is now only used for TLB1.
Reported-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The associativity, not just total size, can differ from the host
hardware.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
As Scott put it:
> If we get a signal after the check, we want to be sure that we don't
> receive the reschedule IPI until after we're in the guest, so that it
> will cause another signal check.
we need to have interrupts disabled from the point we do signal_check()
all the way until we actually enter the guest.
This patch fixes potential signal loss races.
Reported-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Our vcpu kick implementation differs a bit from x86 which resulted in us not
disabling preemption during the kick. Get it a bit closer to what x86 does.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When running the 64-bit Book3s PR code without CONFIG_PREEMPT_NONE, we were
doing a few things wrong, most notably access to PACA fields without making
sure that the pointers stay stable accross the access (preempt_disable()).
This patch moves to_svcpu towards a get/put model which allows us to disable
preemption while accessing the shadow vcpu fields in the PACA. That way we
can run preemptible and everyone's happy!
Reported-by: Jörg Sommer <joerg@alea.gnuu.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Somewhere during merges we ended up from
local_irq_enable()
foo();
local_irq_disable()
to always keeping irqs enabled during that part. However, we now
have the following code:
foo();
local_irq_disable()
which disables interrupts without the surrounding code enabling them
again! So let's remove that disable and be happy.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When entering the guest, we want to make sure we're not getting preempted
away, so let's disable preemption on entry, but enable it again while handling
guest exits.
Reported-by: Jörg Sommer <joerg@alea.gnuu.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Decrementers are now properly driven by TCR/TSR, and the guest
has full read/write access to these registers.
The decrementer keeps ticking (and setting the TSR bit) regardless of
whether the interrupts are enabled with TCR.
The decrementer stops at zero, rather than going negative.
Decrementers (and FITs, once implemented) are delivered as
level-triggered interrupts -- dequeued when the TSR bit is cleared, not
on delivery.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
[scottwood@freescale.com: significant changes]
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This allows additional registers to be accessed by the guest
in PR-mode KVM without trapping.
SPRG4-7 are readable from userspace. On booke, KVM will sync
these registers when it enters the guest, so that accesses from
guest userspace will work. The guest kernel, OTOH, must consistently
use either the real registers or the shared area between exits. This
also applies to the already-paravirted SPRG3.
On non-booke, it's not clear to what extent SPRG4-7 are supported
(they're not architected for book3s, but exist on at least some classic
chips). They are copied in the get/set regs ioctls, but I do not see any
non-booke emulation. I also do not see any syncing with real registers
(in PR-mode) including the user-readable SPRG3. This patch should not
make that situation any worse.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Also fix wrteei 1 paravirt to check for a pending interrupt.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
int_pending was only being lowered if a bit in pending_exceptions
was cleared during exception delivery -- but for interrupts, we clear
it during IACK/TSR emulation. This caused paravirt for enabling
MSR[EE] to be ineffective.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This prevents us from inappropriately blocking in a KVM_SET_REGS
ioctl -- the MSR[WE] will take effect when the guest is next entered.
It also causes SRR1[WE] to be set when we enter the guest's interrupt
handler, which is what e500 hardware is documented to do.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This function should be called with interrupts disabled, to avoid
a race where an exception is delivered after we check, but the
resched kick is received before we disable interrupts (and thus doesn't
actually trigger the exit code that would recheck exceptions).
booke already does this properly in the lightweight exit case, but
not on initial entry.
For now, move the call of prepare_to_enter into subarch-specific code so
that booke can do the right thing here. Ideally book3s would do the same
thing, but I'm having a hard time seeing where it does any interrupt
disabling of this sort (plus it has several additional call sites), so
I'm deferring the book3s fix to someone more familiar with that code.
book3s behavior should be unchanged by this patch.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This function also updates paravirt int_pending, so rename it
to be more obvious that this is a collection of checks run prior
to (re)entering a guest.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently we check prior to returning from a lightweight exit,
but not prior to initial entry.
book3s already does a similar test.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
As per specification the decrementer interrupt not happen when DEC is written
with 0. Also when DEC is zero, no decrementer running. So we should not start
hrtimer for decrementer when DEC = 0.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvmppc_emulate_dec() uses dec_nsec of type unsigned long and does below calculation:
dec_nsec = vcpu->arch.dec;
dec_nsec *= 1000;
This will truncate if DEC value "vcpu->arch.dec" is greater than 0xffff_ffff/1000.
For example : For tb_ticks_per_usec = 4a, we can not set decrementer more than ~58ms.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Acked-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The current implementation of mtmsr and mtmsrd are racy in that it does:
* check (int_pending == 0)
---> host sets int_pending = 1 <---
* write shared page
* done
while instead we should check for int_pending after the shared page is written.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
With hugetlbfs support emerging on e500, we should also support KVM
backing its guest memory by it.
This patch adds support for hugetlbfs into the e500 shadow mmu code.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The hardcoded behavior prevents proper SMP support.
user space shall specify the vcpu's PIR as the vcpu id.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
It should contain the way, not the absolute TLB0 index.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This implements a shared-memory API for giving host userspace access to
the guest's TLB.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Split out the portions of tlbe_priv that should be associated with host
entries into tlbe_ref. Base victim selection on the number of hardware
entries, not guest entries.
For TLB1, where one guest entry can be mapped by multiple host entries,
we use the host tlbe_ref for tracking page references. For the guest
TLB0 entries, we still track it with gtlb_priv, to avoid having to
retranslate if the entry is evicted from the host TLB but not the
guest TLB.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The only place it makes sense to call this function already needs
to have preemption disabled.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Delay allocation of the shadow pid until we're ready to disable
preemption and write the entry.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the access registers to the kvm_run structure.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the general purpose registers to the kvm_run structure.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Add the prefix register to the synced register field in kvm_run.
While we need the prefix register most of the time read-only, this
patch also adds handling for guest dirtying of the prefix register.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
On some cpus the overhead for virtualization instructions is in the same
range as a system call. Having to call multiple ioctls to get set registers
will make certain userspace handled exits more expensive than necessary.
Lets provide a section in kvm_run that works as a shared save area
for guest registers.
We also provide two 64bit flags fields (architecture specific), that will
specify
1. which parts of these fields are valid.
2. which registers were modified by userspace
Each bit for these flag fields will define a group of registers (like
general purpose) or a single register.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
There are several places in the kvm module, which set the prefix register.
Since we need to flush the cpu, lets combine this operation into a helper
function. This helper will also explicitely mask out the unused bits.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
In some cases guests should not provide workarounds for errata even when the
physical processor is affected. For example, because of erratum 400 on family
10h processors a Linux guest will read an MSR (resulting in VMEXIT) before
going to idle in order to avoid getting stuck in a non-C0 state. This is not
necessary: HLT and IO instructions are intercepted and therefore there is no
reason for erratum 400 workaround in the guest.
This patch allows us to present a guest with certain errata as fixed,
regardless of the state of actual hardware.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
We can remove the first ->nx state assignment since it is assigned afterwards anyways.
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch fixes the return code of kvm_arch_vcpu_ioctl in case
of an unkown ioctl number.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch announces a new capability KVM_CAP_S390_UCONTROL that
indicates that kvm can now support virtual machines that are
controlled by userspace.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch fixes definition of the idle_mask and the local_int array
in kvm_s390_float_interrupt. Previous definition had 64 cpus max
hardcoded instead of using KVM_MAX_VCPUS.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch makes sure user controlled virtual machines do not use a
system control area (sca). This is needed in order to create
virtual machines with more cpus than the size of the sca [64].
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch allows the user to fault in pages on a virtual cpus
address space for user controlled virtual machines. Typically this
is superfluous because userspace can just create a mapping and
let the kernel's page fault logic take are of it. There is one
exception: SIE won't start if the lowcore is not present. Normally
the kernel takes care of this [handle_validity() in
arch/s390/kvm/intercept.c] but since the kernel does not handle
intercepts for user controlled virtual machines, userspace needs to
be able to handle this condition.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch disables the in-kernel interrupt stack for KVM virtual
machines that are controlled by user. Userspace has to take care
of handling interrupts on its own.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch disables in-kernel handling of SIE intercepts for user
controlled virtual machines. All intercepts are passed to userspace
via KVM_EXIT_SIE exit reason just like SIE intercepts that cannot be
handled in-kernel for regular KVM guests.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch exports the s390 SIE hardware control block to userspace
via the mapping of the vcpu file descriptor. In order to do so,
a new arch callback named kvm_arch_vcpu_fault is introduced for all
architectures. It allows to map architecture specific pages.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces a new exit reason in the kvm_run structure
named KVM_EXIT_S390_UCONTROL. This exit indicates, that a virtual cpu
has regognized a fault on the host page table. The idea is that
userspace can handle this fault by mapping memory at the fault
location into the cpu's address space and then continue to run the
virtual cpu.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces two ioctls for virtual cpus, that are only
valid for kernel virtual machines that are controlled by userspace.
Each virtual cpu has its individual address space in this mode of
operation, and each address space is backed by the gmap
implementation just like the address space for regular KVM guests.
KVM_S390_UCAS_MAP allows to map a part of the user's virtual address
space to the vcpu. Starting offset and length in both the user and
the vcpu address space need to be aligned to 1M.
KVM_S390_UCAS_UNMAP can be used to unmap a range of memory from a
virtual cpu in a similar way.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces a new config option for user controlled kernel
virtual machines. It introduces a parameter to KVM_CREATE_VM that
allows to set bits that alter the capabilities of the newly created
virtual machine.
The parameter is passed to kvm_arch_init_vm for all architectures.
The only valid modifier bit for now is KVM_VM_S390_UCONTROL.
This requires CAP_SYS_ADMIN privileges and creates a user controlled
virtual machine on s390 architectures.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
get_written_sptes is called twice in kvm_mmu_pte_write, one of them can be
removed
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
