KVM-PR currently does not support transactional memory, and the
implementation in TCG is just a fake. We should not announce TM
support in the ibm,pa-features property when running on such a
system, so disable it by default and only enable it if the KVM
implementation supports it (i.e. recent versions of KVM-HV).
These changes are based on some earlier work from Anton Blanchard
(thanks!).
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
These are mandatory per PAPR and available on Linux 4.3 and newer kernels. The calls in question are required to run FreeBSD guests with reasonable performance, so enable them if possible.
Signed-off-by: Nathan Whitehorn <nwhitehorn@freebsd.org>
[dwg: Added a stub to fix compile without KVM (e.g. on x86 host)]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When running with KVM, we might be interested in some details
of the host CPU class, too, so provide a function to get the
corresponding CPU class.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
6a81dd17 "spapr_iommu: Rename vfio_accel parameter" renamed vfio_accel
flag everywhere but one spot was missed.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When a Power cpu with 64-bit hash MMU has it's hash page table (HPT)
pointer updated by a write to the SDR1 register we need to update some
derived variables. Likewise, when the cpu is configured for an external
HPT (one not in the guest memory space) some derived variables need to be
updated.
Currently the logic for this is (partially) duplicated in ppc_store_sdr1()
and in spapr_cpu_reset(). In future we're going to need it in some other
places, so make some common helpers for this update.
In addition the new ppc_hash64_set_external_hpt() helper also updates
SDR1 in KVM - it's not updated by the normal runtime KVM <-> qemu CPU
synchronization. In a sense this belongs logically in the
ppc_hash64_set_sdr1() helper, but that is called from
kvm_arch_get_registers() so can't itself call cpu_synchronize_state()
without infinite recursion. In practice this doesn't matter because
the only other caller is TCG specific.
Currently there aren't situations where updating SDR1 at runtime in KVM
matters, but there are going to be in future.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
This hypercall either initializes a page with zeros, or copies
another page.
According to LoPAPR, the i-cache of the page should also be
flushed if using H_ICACHE_INVALIDATE or H_ICACHE_SYNCHRONIZE,
and the d-cache should be synchronized to the RAM if the
H_ICACHE_SYNCHRONIZE flag is used. For this, two new functions
are introduced, kvmppc_dcbst_range() and kvmppc_icbi()_range, which
use the corresponding assembler instructions to flush the caches
if running with KVM on Power. If the code runs with TCG instead,
the code only uses tb_flush(), assuming that this will be
enough for synchronization.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This KVM stub implementation isn't used anywhere.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
This stub function is in the !KVM ifdef in target-ppc/kvm_ppc.h. However
no such function exists on the KVM side, or is ever used.
I think this originally referenced a function which read host page size
information from /proc, for we we now use the KVM GET_SMMU_INFO extension
instead.
In any case, it has no function now, so remove it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
The !CONFIG_KVM implementation of kvmppc_reset_htab() returns -1
by default. Change this to return 0 so that we fall back to user space
HTAB allocation for emulated guests.
This fixes the make check failures for ppc64 emulated target.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The vfio_accel parameter used when creating a new TCE table (guest IOMMU
context) has a confusing name. What it really means is whether we need the
TCE table created to be able to support VFIO devices.
VFIO is relevant, because when available we use in-kernel acceleration of
the TCE table, but that may not work with VFIO devices because updates to
the table are handled in kernel, bypass qemu and so don't hit qemu's
infrastructure for keeping the VFIO host IOMMU state in sync with the guest
IOMMU state.
Rename the parameter to "need_vfio" throughout. This is a cosmetic change,
with no impact on the logic.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
The PAPR interface defines a hypercall to pass high-quality
hardware generated random numbers to guests. Recent kernels can
already provide this hypercall to the guest if the right hardware
random number generator is available. But in case the user wants
to use another source like EGD, or QEMU is running with an older
kernel, we should also have this call in QEMU, so that guests that
do not support virtio-rng yet can get good random numbers, too.
This patch now adds a new pseudo-device to QEMU that either
directly provides this hypercall to the guest or is able to
enable the in-kernel hypercall if available. The in-kernel
hypercall can be enabled with the use-kvm property, e.g.:
qemu-system-ppc64 -device spapr-rng,use-kvm=true
For handling the hypercall in QEMU instead, a "RngBackend" is
required since the hypercall should provide "good" random data
instead of pseudo-random (like from a "simple" library function
like rand() or g_random_int()). Since there are multiple RngBackends
available, the user must select an appropriate back-end via the
"rng" property of the device, e.g.:
qemu-system-ppc64 -object rng-random,filename=/dev/hwrng,id=gid0 \
-device spapr-rng,rng=gid0 ...
See http://wiki.qemu-project.org/Features-Done/VirtIORNG for
other example of specifying RngBackends.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
For setting debug watchpoints, sPAPR guests use H_SET_MODE hypercall.
The existing QEMU H_SET_MODE handler does not support this but
the KVM handler in HV KVM does. However it is not enabled.
This enables the in-kernel H_SET_MODE handler which handles:
- Completed Instruction Address Breakpoint Register
- Watch point 0 registers.
The rest is still handled in QEMU.
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
QEMU does have an I/O thread now, that can be interrupted at any time
because the VCPU thread runs outside the iothread mutex.
Therefore, the kvmppc_timer_hack is obsolete. Remove it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
qemu currently implements the hypercalls H_LOGICAL_CI_LOAD and
H_LOGICAL_CI_STORE as PAPR extensions. These are used by the SLOF firmware
for IO, because performing cache inhibited MMIO accesses with the MMU off
(real mode) is very awkward on POWER.
This approach breaks when SLOF needs to access IO devices implemented
within KVM instead of in qemu. The simplest example would be virtio-blk
using an iothread, because the iothread / dataplane mechanism relies on
an in-kernel implementation of the virtio queue notification MMIO.
To fix this, an in-kernel implementation of these hypercalls has been made,
(kernel commit 99342cf "kvmppc: Implement H_LOGICAL_CI_{LOAD,STORE} in KVM"
however, the hypercalls still need to be enabled from qemu. This performs
the necessary calls to do so.
It would be nice to provide some warning if we encounter a problematic
device with a kernel which doesn't support the new calls. Unfortunately,
I can't see a way to detect this case which won't either warn in far too
many cases that will probably work, or which is horribly invasive.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Useful for identifying the guest/host uniquely within the
guest. Adding following properties to the guest root node.
vm,uuid - uuid of the guest
host-model - Host model number
host-serial - Host machine serial number
hypervisor type - Tells its "kvm"
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
PPC970 does not support VRMA (virtual RMA) so real memory required
for SLOF to execute must be allocated by the KVM_ALLOCATE_RMA ioctl.
Later this memory is used as a part of the guest RAM area.
The RMA allocating code also registers a memory region for this piece
of RAM.
We are going to simplify memory regions layout: RMA memory region
will be a subregion in the RAM memory region, both starting from zero.
This way we will not have to take care of start address alignment for
the piece of RAM next to the RMA.
This moves memory region business closer to the RAM memory region
creation/allocation code.
As this is a mechanical patch, no change in behaviour is expected.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[agraf: fix compilation on non-kvm systems]
Signed-off-by: Alexander Graf <agraf@suse.de>
POWER KVM supports an KVM_CAP_SPAPR_TCE capability which allows allocating
TCE tables in the host kernel memory and handle H_PUT_TCE requests
targeted to specific LIOBN (logical bus number) right in the host without
switching to QEMU. At the moment this is used for emulated devices only
and the handler only puts TCE to the table. If the in-kernel H_PUT_TCE
handler finds a LIOBN and corresponding table, it will put a TCE to
the table and complete hypercall execution. The user space will not be
notified.
Upcoming VFIO support is going to use the same sPAPRTCETable device class
so KVM_CAP_SPAPR_TCE is going to be used as well. That means that TCE
tables for VFIO are going to be allocated in the host as well.
However VFIO operates with real IOMMU tables and simple copying of
a TCE to the real hardware TCE table will not work as guest physical
to host physical address translation is requited.
So until the host kernel gets VFIO support for H_PUT_TCE, we better not
to register VFIO's TCE in the host.
This adds a place holder for KVM_CAP_SPAPR_TCE_VFIO capability. It is not
in upstream yet and being discussed so now it is always false which means
that in-kernel VFIO acceleration is not supported.
This adds a bool @vfio_accel flag to the sPAPRTCETable device telling
that sPAPRTCETable should not try allocating TCE table in the host kernel
for VFIO. The flag is false now as at the moment there is no VFIO.
This adds an vfio_accel parameter to spapr_tce_new_table(), the semantic
is the same. Since there is only emulated PCI and VIO now, the flag is set
to false. Upcoming VFIO support will set it to true.
This is a preparation patch so no change in behaviour is expected
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>
New kvm versions expose a PPC_FIXUP_HCALL capability. Make it visible to
machine code so we can take decisions based on it.
Signed-off-by: Alexander Graf <agraf@suse.de>
This removes window_size as it is basically a copy of nb_table
shifted by SPAPR_TCE_PAGE_SHIFT. As new dynamic DMA windows are
going to support windows as big as the entire RAM and this number
will be bigger that 32 capacity, we will have to do something
about @window_size anyway and removal seems to be the right way to go.
This removes dma_window_start/dma_window_size from sPAPRPHBState as
they are no longer used.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently only single TCE entry per request is supported (H_PUT_TCE).
However PAPR+ specification allows multiple entry requests such as
H_PUT_TCE_INDIRECT and H_STUFF_TCE. Having less transitions to the host
kernel via ioctls, support of these calls can accelerate IOMMU operations.
This implements H_STUFF_TCE and H_PUT_TCE_INDIRECT.
This advertises "multi-tce" capability to the guest if the host kernel
supports it (KVM_CAP_SPAPR_MULTITCE) or guest is running in TCG mode.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>
The host kernel implements a KVM_REG_PPC_ARCH_COMPAT register which
this uses to enable a compatibility mode if any chosen.
This sets the KVM_REG_PPC_ARCH_COMPAT register in KVM. ppc_set_compat()
signals the caller if the mode cannot be enabled by the host kernel.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[agraf: fix TCG compat setting]
Signed-off-by: Alexander Graf <agraf@suse.de>
Normally CPUState::cpu_index is used to pick the right CPU for various
operations. However default consecutive numbering does not always work
for POWERPC.
These indexes are reflected in /proc/device-tree/cpus/PowerPC,POWER7@XX
and used to call KVM VCPU's ioctls. In order to achieve this,
kvmppc_fixup_cpu() was introduced. Roughly speaking, it multiplies
cpu_index by the number of threads per core.
This approach has disadvantages such as:
1. NUMA configuration stays broken after the fixup;
2. CPU-targeted commands from the QEMU Monitor do not work properly as
CPU indexes have been fixed and there is no clear way for the user to
know what the new CPU indexes are.
This introduces a @cpu_dt_id field in the CPUPPCState struct which
is initialized from @cpu_index by default and can be fixed later
to meet the device tree requirements.
This adds an API to handle @cpu_dt_id.
This removes kvmppc_fixup_cpu() as it is not more needed, @cpu_dt_id
is calculated in ppc_cpu_realize().
This will be used later in machine code.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Mike Day <ncmike@ncultra.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This support updating htab managed by the hypervisor. Currently we don't have
any user for this feature. This actually bring the store_hpte interface
in-line with the load_hpte one. We may want to use this when we want to
emulate henter hcall in qemu for HV kvm.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[ folded fix for the "warn_unused_result" build break in
kvmppc_hash64_write_pte(), Greg Kurz <gkurz@linux.vnet.ibm.com> ]
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
With kvm enabled, we store the hash page table information in the hypervisor.
Use ioctl to read the htab contents. Without this we get the below error when
trying to read the guest address
(gdb) x/10 do_fork
0xc000000000098660 <do_fork>: Cannot access memory at address 0xc000000000098660
(gdb)
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[ fixes for 32 bit build (casts!), ldq_phys() API change,
Greg Kurz <gkurz@linux.vnet.ibm.com ]
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Recent PowerKVM allows the kernel to intercept some RTAS calls from the
guest directly. This is used to implement the more efficient in-kernel
XICS for example. qemu is still responsible for assigning the RTAS token
numbers however, and needs to tell the kernel which RTAS function name is
assigned to a given token value. This patch adds a convenience wrapper for
the KVM_PPC_RTAS_DEFINE_TOKEN ioctl() which is used for this purpose.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
At present, the savevm / migration support for the pseries machine will not
work when KVM is enabled. That's because KVM manages the guest's hash page
table in the host kernel, so qemu has no visibility of it. This patch
fixes this by using new kernel interfaces to extract and reinsert the
guest's hash table during the migration process.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-id: 1374175984-8930-11-git-send-email-aliguori@us.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Enable the KVM emulated watchdog if KVM supports (use the
capability enablement in watchdog handler). Also watchdog exit
(KVM_EXIT_WATCHDOG) handling is added.
Watchdog state machine is cleared whenever VM state changes to running.
This is to handle the cases like return from debug halt etc.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
[agraf: rebase to current code base, fix non-kvm cases]
Signed-off-by: Alexander Graf <agraf@suse.de>
Older KVM versions don't support EPR which breaks guests when we announce
MPIC variants that support EPR.
Catch that case and expose only MPIC version 2.0 which tells the guest that
we don't support the EPR capability yet.
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
[agraf: Add comment, route cap check through kvm_ppc.c]
Signed-off-by: Alexander Graf <agraf@suse.de>
Note that target-alpha accesses this field from TCG, now using a
negative offset. Therefore the field is placed last in CPUState.
Pass PowerPCCPU to [kvm]ppc_fixup_cpu() to facilitate this change.
Move common parts of mips cpu_state_reset() to mips_cpu_reset().
Acked-by: Richard Henderson <rth@twiddle.net> (for alpha)
[AF: Rebased onto ppc CPU subclasses and openpic changes]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Since the model list is highly macrofied, keep ppc_def_t for now and
save a pointer to it in PowerPCCPUClass. This results in a flat list of
subclasses including aliases, to be refined later.
Move cpu_ppc_init() to translate_init.c and drop helper.c.
Long-term the idea is to turn translate_init.c into a standalone cpu.c.
Inline cpu_ppc_usable() into type registration.
Split cpu_ppc_register() in two by code movement into the initfn and
by turning the remaining part into a realizefn.
Move qemu_init_vcpu() call into the new realizefn and adapt
create_ppc_opcodes() to return an Error.
Change ppc_find_by_pvr() -> ppc_cpu_class_by_pvr().
Change ppc_find_by_name() -> ppc_cpu_class_by_name().
Turn -cpu host into its own subclass. This requires to move the
kvm_enabled() check in ppc_cpu_class_by_name() to avoid the class being
found via the normal name lookup in the !kvm_enabled() case.
Turn kvmppc_host_cpu_def() into the class_init and add an initfn that
asserts KVM is in fact enabled.
Implement -cpu ? and the QMP equivalent in terms of subclasses.
This newly exposes -cpu host to the user, ordered last for -cpu ?.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
On e500mc, the platform doesn't provide a way for the CPU to go idle.
To still not uselessly burn CPU time, expose an idle hypercall to the guest
if kvm supports it.
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
[agraf: adjust for current code base, add patch description, fix non-kvm case]
Signed-off-by: Alexander Graf <agraf@suse.de>
This adds support for then new "reset htab" ioctl which allows qemu
to properly cleanup the MMU hash table when the guest is reset. With
the corresponding kernel support, reset of a guest now works properly.
This also paves the way for indicating a different size hash table
to the kernel and for the kernel to be able to impose limits on
the requested size.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
More recent Power server chips (i.e. based on the 64 bit hash MMU)
support more than just the traditional 4k and 16M page sizes. This
can get quite complicated, because which page sizes are supported,
which combinations are supported within an MMU segment and how these
page sizes are encoded both in the SLB entry and the hash PTE can vary
depending on the CPU model (they are not specified by the
architecture). In addition the firmware or hypervisor may not permit
use of certain page sizes, for various reasons. Whether various page
sizes are supported on KVM, for example, depends on whether the PR or
HV variant of KVM is in use, and on the page size of the memory
backing the guest's RAM.
This patch adds information to the CPUState and cpu defs to describe
the supported page sizes and encodings. Since TCG does not yet
support any extended page sizes, we just set this to NULL in the
static CPU definitions, expanding this to the default 4k and 16M page
sizes when we initialize the cpu state. When using KVM, however, we
instead determine available page sizes using the new
KVM_PPC_GET_SMMU_INFO call. For old kernels without that call, we use
some defaults, with some guesswork which should do the right thing for
existing HV and PR implementations. The fallback might not be correct
for future versions, but that's ok, because they'll have
KVM_PPC_GET_SMMU_INFO.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
On target-ppc, our table of CPU types and features encodes the features as
found on the hardware, regardless of whether these features are actually
usable under TCG or KVM. We already have cases where the information from
the cpu table must be fixed up to account for limitations in the emulation
method we're using. e.g. TCG does not support the DFP and VSX instructions
and KVM needs different numbering of the CPUs in order to tell it the
correct thread to core mappings.
This patch cleans up these hacks to handle emulation limitations by
consolidating them into a pair of functions specifically for the purpose.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[AF: Style and typo fixes, rename new functions and drop ppc_def_t arg]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Scripted conversion:
sed -i "s/CPUState/CPUPPCState/g" target-ppc/*.[hc]
sed -i "s/#define CPUPPCState/#define CPUState/" target-ppc/cpu.h
Signed-off-by: Andreas Färber <afaerber@suse.de>
Acked-by: Anthony Liguori <aliguori@us.ibm.com>
The recent usage of MemoryRegion in kvm_ppc.h breaks builds with
CONFIG_USER_ONLY=y. This patch fixes it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
For convenience with kvm, x86 allows the user to specify -cpu host on the
qemu command line, which means make the guest cpu the same as the host
cpu. This patch implements the same option for ppc targets.
For now, this just read the host PVR (Processor Version Register) and
selects one of our existing CPU specs based on it. This means that the
option will not work if the host cpu is not supported by TCG, even if that
wouldn't matter for use under kvm.
In future, we can extend this in future to override parts of the cpu spec
based on information obtained from the host (via /proc/cpuinfo, the host
device tree, or explicit KVM calls). That will let us handle cases where
the real kvm-virtualized CPU doesn't behave exactly like the TCG-emulated
CPU. With appropriate annotation of the CPU specs we'll also then be able
to use host cpus under kvm even when there isn't a matching full TCG model.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Sufficiently recent PAPR specifications define properties "ibm,vmx"
and "ibm,dfp" on the CPU node which advertise whether the VMX vector
extensions (or the later VSX version) and/or the Decimal Floating
Point operations from IBM's recent POWER CPUs are available.
Currently we do not put these in the guest device tree and the guest
kernel will consequently assume they are not available. This is good,
because they are not supported under TCG. VMX is similar enough to
Altivec that it might be trivial to support, but VSX and DFP would
both require significant work to support in TCG.
However, when running under kvm on a host which supports these
instructions, there's no reason not to let the guest use them. This
patch, therefore, checks for the relevant support on the host CPU
and, if present, advertises them to the guest as well.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
The pseries machine of qemu implements the TCE mechanism used as a
virtual IOMMU for the PAPR defined virtual IO devices. Because the
PAPR spec only defines a small DMA address space, the guest VIO
drivers need to update TCE mappings very frequently - the virtual
network device is particularly bad. This means many slow exits to
qemu to emulate the H_PUT_TCE hypercall.
Sufficiently recent kernels allow this to be mitigated by implementing
H_PUT_TCE in the host kernel. To make use of this, however, qemu
needs to initialize the necessary TCE tables, and map them into itself
so that the VIO device implementations can retrieve the mappings when
they access guest memory (which is treated as a virtual DMA
operation).
This patch adds the necessary calls to use the KVM TCE acceleration.
If the kernel does not support acceleration, or there is some other
error creating the accelerated TCE table, then it will still fall back
to full userspace TCE implementation.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
At present, using the hypervisor aware Book3S-HV KVM will only work
with qemu on POWER7 CPUs. PPC970 CPUs also have hypervisor
capability, but they lack the VRMA feature which makes assigning guest
memory easier.
In order to allow KVM Book3S-HV on PPC970, we need to specially
allocate the first chunk of guest memory (the "Real Mode Area" or
RMA), so that it is physically contiguous.
Sufficiently recent host kernels allow such contiguous RMAs to be
allocated, with a kvm capability advertising whether the feature is
available and/or necessary on this hardware. This patch enables qemu
to use this support, thus allowing kvm acceleration of pseries qemu
machines on PPC970 hardware.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
agraf: fix to use memory api
Alex Graf has already made qemu support KVM for the pseries machine
when using the Book3S-PR KVM variant (which runs the guest in
usermode, emulating supervisor operations). This code allows gets us
very close to also working with KVM Book3S-HV (using the hypervisor
capabilities of recent POWER CPUs).
This patch moves us another step towards Book3S-HV support by
correctly handling SMT (multithreaded) POWER CPUs. There are two
parts to this:
* Querying KVM to check SMT capability, and if present, adjusting the
cpu numbers that qemu assigns to cause KVM to assign guest threads
to cores in the right way (this isn't automatic, because the POWER
HV support has a limitation that different threads on a single core
cannot be in different guests at the same time).
* Correctly informing the guest OS of the SMT thread to core mappings
via the device tree.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
When running PR style KVM, we need to tell the kernel that we want
to run in PAPR mode now. This means that we need to pass some more
register information down and enable papr mode. We also need to align
the HTAB to htab_size boundary.
Using this patch, -M pseries works with kvm even on non-hv kvm
implementations, as long as the preceding kernel patches are in.
Signed-off-by: Alexander Graf <agraf@suse.de>
---
v1 -> v2:
- match on CONFIG_PSERIES
v2 -> v3:
- remove HIOR pieces from PAPR patch (ABI breakage)
We have a bunch of helper functions that don't have any stubs for them in case
we don't have CONFIG_KVM enabled. That didn't bite us so far, because gcc can
optimize them out pretty well, but we should really provide them.
Signed-off-by: Alexander Graf <agraf@suse.de>
---
v1 -> v2:
- use uint64_t for clockfreq
