This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.
V2->V2
- Fix up to work against 3.18-rc1
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that AltiVec and hardware thread support is in place enable e6500 core.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
ePAPR represents hardware threads as cpu node properties in device tree.
So with existing QEMU, hardware threads are simply exposed as vcpus with
one hardware thread.
The e6500 core shares TLBs between hardware threads. Without tlb write
conditional instruction, the Linux kernel uses per core mechanisms to
protect against duplicate TLB entries.
The guest is unable to detect real siblings threads, so it can't use the
TLB protection mechanism. An alternative solution is to use the hypervisor
to allocate different lpids to guest's vcpus that runs simultaneous on real
siblings threads. On systems with two threads per core this patch halves
the size of the lpid pool that the allocator sees and use two lpids per VM.
Use even numbers to speedup vcpu lpid computation with consecutive lpids
per VM: vm1 will use lpids 2 and 3, vm2 lpids 4 and 5, and so on.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: fix spelling]
Signed-off-by: Alexander Graf <agraf@suse.de>
Increase FPU laziness by loading the guest state into the unit before entering
the guest instead of doing it on each vcpu schedule. Without this improvement
an interrupt may claim floating point corrupting guest state.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch changes the default behavior of MSRP_DEP, that is
guest is not allowed to change the MSR_DE, to guest can change
MSR_DE. When userspace is debugging guest then it override the
default behavior and set MSRP_DEP. This stops guest to change
MSR_DE when userspace is debugging guest.
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
We now support SPRG9 for guest, so also add a one reg interface for same
Note: Changes are in bookehv code only as we do not have SPRG9 on booke-pr.
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
On vcpu schedule, the condition checked for tlb pollution is too loose.
The tlb entries of a vcpu become polluted (vs stale) only when a different
vcpu within the same logical partition runs in-between. Optimize the tlb
invalidation condition keeping last_vcpu per logical partition id.
With the new invalidation condition, a guest shows 4% performance improvement
on P5020DS while running a memory stress application with the cpu oversubscribed,
the other guest running a cpu intensive workload.
Guest - old invalidation condition
real 3.89
user 3.87
sys 0.01
Guest - enhanced invalidation condition
real 3.75
user 3.73
sys 0.01
Host
real 3.70
user 1.85
sys 0.00
The memory stress application accesses 4KB pages backed by 75% of available
TLB0 entries:
char foo[ENTRIES][4096] __attribute__ ((aligned (4096)));
int main()
{
char bar;
int i, j;
for (i = 0; i < ITERATIONS; i++)
for (j = 0; j < ENTRIES; j++)
bar = foo[j][0];
return 0;
}
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Reviewed-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Systems that support automatic loading of kernel modules through
device aliases should try and automatically load kvm when /dev/kvm
gets opened.
Add code to support that magic for all PPC kvm targets, even the
ones that don't support modules yet.
Signed-off-by: Alexander Graf <agraf@suse.de>
This moves the kvmppc_ops callbacks to be a per VM entity. This
enables us to select HV and PR mode when creating a VM. We also
allow both kvm-hv and kvm-pr kernel module to be loaded. To
achieve this we move /dev/kvm ownership to kvm.ko module. Depending on
which KVM mode we select during VM creation we take a reference
count on respective module
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[agraf: fix coding style]
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch add a new callback kvmppc_ops. This will help us in enabling
both HV and PR KVM together in the same kernel. The actual change to
enable them together is done in the later patch in the series.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[agraf: squash in booke changes]
Signed-off-by: Alexander Graf <agraf@suse.de>
The previous patch made 64-bit booke KVM build again, but Altivec
support is still not complete, and we can't prevent the guest from
turning on Altivec (which can corrupt host state until state
save/restore is implemented). Disable e6500 on KVM until this is
fixed.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Pull kvm updates from Gleb Natapov:
"Highlights of the updates are:
general:
- new emulated device API
- legacy device assignment is now optional
- irqfd interface is more generic and can be shared between arches
x86:
- VMCS shadow support and other nested VMX improvements
- APIC virtualization and Posted Interrupt hardware support
- Optimize mmio spte zapping
ppc:
- BookE: in-kernel MPIC emulation with irqfd support
- Book3S: in-kernel XICS emulation (incomplete)
- Book3S: HV: migration fixes
- BookE: more debug support preparation
- BookE: e6500 support
ARM:
- reworking of Hyp idmaps
s390:
- ioeventfd for virtio-ccw
And many other bug fixes, cleanups and improvements"
* tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits)
kvm: Add compat_ioctl for device control API
KVM: x86: Account for failing enable_irq_window for NMI window request
KVM: PPC: Book3S: Add API for in-kernel XICS emulation
kvm/ppc/mpic: fix missing unlock in set_base_addr()
kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write
kvm/ppc/mpic: remove users
kvm/ppc/mpic: fix mmio region lists when multiple guests used
kvm/ppc/mpic: remove default routes from documentation
kvm: KVM_CAP_IOMMU only available with device assignment
ARM: KVM: iterate over all CPUs for CPU compatibility check
KVM: ARM: Fix spelling in error message
ARM: KVM: define KVM_ARM_MAX_VCPUS unconditionally
KVM: ARM: Fix API documentation for ONE_REG encoding
ARM: KVM: promote vfp_host pointer to generic host cpu context
ARM: KVM: add architecture specific hook for capabilities
ARM: KVM: perform HYP initilization for hotplugged CPUs
ARM: KVM: switch to a dual-step HYP init code
ARM: KVM: rework HYP page table freeing
ARM: KVM: enforce maximum size for identity mapped code
ARM: KVM: move to a KVM provided HYP idmap
...
Extend processor compatibility names to e6500 cores.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
MMU registers were exposed to user-space using sregs interface. Add them
to ONE_REG interface using kvmppc_get_one_reg/kvmppc_set_one_reg delegation
mechanism.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Refactor Book3E ONE_REG ioctl implementation to use kvmppc_get_one_reg/
kvmppc_set_one_reg delegation interface introduced by Book3S. This is
necessary for MMU SPRs which are platform specifics.
Get rid of useless case braces in the process.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The existing check handles the case where we've migrated to a different
core than we last ran on, but it doesn't handle the case where we're
still on the same cpu we last ran on, but some other vcpu has run on
this cpu in the meantime.
Without this, guest segfaults (and other misbehavior) have been seen in
smp guests.
Cc: stable@vger.kernel.org # 3.8.x
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
tlbilxva emulation was using an u32 variable for guest effective address.
Replace it with gva_t type to handle 64-bit guests.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
64-bit host needs to remain in 64-bit mode when an exception take place.
Set interrupt computaion mode in EPCR register.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Add processor support for e500mc, using hardware virtualization support
(GS-mode).
Current issues include:
- No support for external proxy (coreint) interrupt mode in the guest.
Includes work by Ashish Kalra <Ashish.Kalra@freescale.com>,
Varun Sethi <Varun.Sethi@freescale.com>, and
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>
Adam Buchbinder