KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
We needed the lock to avoid racing with creation of the irqchip on x86. As
kvm_set_irq_routing() calls srcu_synchronize_expedited(), this lock
might be held for a longer time.
Let's introduce an arch specific callback to check if we can actually
add irq routes. For x86, all we have to do is check if we have an
irqchip in the kernel. We don't need kvm->lock at that point as the
irqchip is marked as inititalized only when actually fully created.
Reported-by: Steve Rutherford <srutherford@google.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Fixes: 1df6ddede10a ("KVM: x86: race between KVM_SET_GSI_ROUTING and KVM_CREATE_IRQCHIP") Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 27 Apr 2017 15:33:14 +0000 (17:33 +0200)]
Merge tag 'kvm-arm-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/ARM Changes for v4.12.
Changes include:
- Using the common sysreg definitions between KVM and arm64
- Improved hyp-stub implementation with support for kexec and kdump on the 32-bit side
- Proper PMU exception handling
- Performance improvements of our GIC handling
- Support for irqchip in userspace with in-kernel arch-timers and PMU support
- A fix for a race condition in our PSCI code
According to the Intel SDM, "Certain exceptions have priority over VM
exits. These include invalid-opcode exceptions, faults based on
privilege level*, and general-protection exceptions that are based on
checking I/O permission bits in the task-state segment (TSS)."
There is no need to check for faulting conditions that the hardware
has already checked.
* These include faults generated by attempts to execute, in
virtual-8086 mode, privileged instructions that are not recognized
in that mode.
Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: fix emulation of RSM and IRET instructions
On AMD, the effect of set_nmi_mask called by emulate_iret_real and em_rsm
on hflags is reverted later on in x86_emulate_instruction where hflags are
overwritten with ctxt->emul_flags (the kvm_set_hflags call). This manifests
as a hang when rebooting Windows VMs with QEMU, OVMF, and >1 vcpu.
Instead of trying to merge ctxt->emul_flags into vcpu->arch.hflags after
an instruction is emulated, this commit deletes emul_flags altogether and
makes the emulator access vcpu->arch.hflags using two new accessors. This
way all changes, on the emulator side as well as in functions called from
the emulator and accessing vcpu state with emul_to_vcpu, are preserved.
More details on the bug and its manifestation with Windows and OVMF:
It's a KVM bug in the interaction between SMI/SMM and NMI, specific to AMD.
I believe that the SMM part explains why we started seeing this only with
OVMF.
KVM masks and unmasks NMI when entering and leaving SMM. When KVM emulates
the RSM instruction in em_rsm, the set_nmi_mask call doesn't stick because
later on in x86_emulate_instruction we overwrite arch.hflags with
ctxt->emul_flags, effectively reverting the effect of the set_nmi_mask call.
The AMD-specific hflag of interest here is HF_NMI_MASK.
When rebooting the system, Windows sends an NMI IPI to all but the current
cpu to shut them down. Only after all of them are parked in HLT will the
initiating cpu finish the restart. If NMI is masked, other cpus never get
the memo and the initiating cpu spins forever, waiting for
hal!HalpInterruptProcessorsStarted to drop. That's the symptom we observe.
Fixes: a584539b24b8 ("KVM: x86: pass the whole hflags field to emulator and back") Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 27 Apr 2017 12:33:43 +0000 (14:33 +0200)]
KVM: mark requests that need synchronization
kvm_make_all_requests() provides a synchronization that waits until all
kicked VCPUs have acknowledged the kick. This is important for
KVM_REQ_MMU_RELOAD as it prevents freeing while lockless paging is
underway.
This patch adds the synchronization property into all requests that are
currently being used with kvm_make_all_requests() in order to preserve
the current behavior and only introduce a new framework. Removing it
from requests where it is not necessary is left for future patches.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrew Jones [Wed, 26 Apr 2017 20:32:24 +0000 (22:32 +0200)]
KVM: add explicit barrier to kvm_vcpu_kick
kvm_vcpu_kick() must issue a general memory barrier prior to reading
vcpu->mode in order to ensure correctness of the mutual-exclusion
memory barrier pattern used with vcpu->requests. While the cmpxchg
called from kvm_vcpu_kick():
implies general memory barriers before and after the operation, that
implication is only valid when cmpxchg succeeds. We need an explicit
barrier for when it fails, otherwise a VCPU thread on its entry path
that reads zero for vcpu->requests does not exclude the possibility
the requesting thread sees !IN_GUEST_MODE when it reads vcpu->mode.
kvm_make_all_cpus_request already had a barrier, so we remove it, as
now it would be redundant.
Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
and kvm_vcpu_kick() wakes up the target vcpu. We know which requests do
not need the wake up and use it to optimize the loop.
Thanks to that, this patch doesn't change the behavior of current users
(the all don't need the wake up) and only prepares for future where the
wake up is going to be needed.
I think that most requests do not need the wake up, so we would flip the
bit then.
Later on, kvm_make_request() will take care of kicking too, using this
bit to make the decision whether to kick or not.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some operations must ensure that the guest is not running with stale
data, but if the guest is halted, then the update can wait until another
event happens. kvm_make_all_requests() currently doesn't wake up, so we
can mark all requests used with it.
First 8 bits were arbitrarily reserved for request numbers.
Most uses of requests have the request type as a constant, so a compiler
will optimize the '&'.
An alternative would be to have an inline function that would return
whether the request needs a wake-up or not, but I like this one better
even though it might produce worse assembly.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: always use kvm_make_request instead of set_bit
Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: add kvm_{test,clear}_request to replace {test,clear}_bit
Users were expected to use kvm_check_request() for testing and clearing,
but request have expanded their use since then and some users want to
only test or do a faster clear.
Make sure that requests are not directly accessed with bit operations.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Jason J. Herne [Mon, 20 Mar 2017 13:57:42 +0000 (09:57 -0400)]
s390: kvm: Cpu model support for msa6, msa7 and msa8
msa6 and msa7 require no changes.
msa8 adds kma instruction and feature area.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Jason J. Herne [Thu, 2 Feb 2017 13:25:19 +0000 (08:25 -0500)]
s390/cpacf: Introduce kma instruction
Provide a kma instruction definition for use by callers of __cpacf_query.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Jason J. Herne [Tue, 21 Feb 2017 14:00:54 +0000 (09:00 -0500)]
s390/cpacf: query instructions use unique parameters for compatibility with KMA
The new KMA instruction requires unique parameters. Update __cpacf_query to
generate a compatible assembler instruction.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Acked-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: x86: remove irq disablement around KVM_SET_CLOCK/KVM_GET_CLOCK
The disablement of interrupts at KVM_SET_CLOCK/KVM_GET_CLOCK
attempts to disable software suspend from causing "non atomic behaviour" of
the operation:
Add a helper function to compute the kernel time and convert nanoseconds
back to CPU specific cycles. Note that these must not be called in preemptible
context, as that would mean the kernel could enter software suspend state,
which would cause non-atomic operation.
However, assume the kernel can enter software suspend at the following 2 points:
monotonic_to_bootbased() should be correct relative to a ktime_get_ts(&ts)
performed after point 1 (that is after resuming from software suspend),
hypothetical_ktime_get_ts()
Therefore it is also correct for the ktime_get_ts(&ts) before point 1,
which is
Note CLOCK_MONOTONIC does not count during suspension.
So remove the irq disablement, which causes the following warning on
-RT kernels:
With this reasoning, and the -RT bug that the irq disablement causes
(because spin_lock is now a sleeping lock), remove the IRQ protection as it
causes:
Guests that are heavy on futexes end up IPI'ing each other a lot. That
can lead to significant slowdowns and latency increase for those guests
when running within KVM.
If only a single guest is needed on a host, we have a lot of spare host
CPU time we can throw at the problem. Modern CPUs implement a feature
called "MWAIT" which allows guests to wake up sleeping remote CPUs without
an IPI - thus without an exit - at the expense of never going out of guest
context.
The decision whether this is something sensible to use should be up to the
VM admin, so to user space. We can however allow MWAIT execution on systems
that support it properly hardware wise.
This patch adds a CAP to user space and a KVM cpuid leaf to indicate
availability of native MWAIT execution. With that enabled, the worst a
guest can do is waste as many cycles as a "jmp ." would do, so it's not
a privilege problem.
We consciously do *not* expose the feature in our CPUID bitmap, as most
people will want to benefit from sleeping vCPUs to allow for over commit.
Reported-by: "Gabriel L. Somlo" <gsomlo@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
[agraf: fix amd, change commit message] Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Kyle Huey [Mon, 20 Mar 2017 08:16:28 +0000 (01:16 -0700)]
KVM: x86: virtualize cpuid faulting
Hardware support for faulting on the cpuid instruction is not required to
emulate it, because cpuid triggers a VM exit anyways. KVM handles the relevant
MSRs (MSR_PLATFORM_INFO and MSR_MISC_FEATURES_ENABLE) and upon a
cpuid-induced VM exit checks the cpuid faulting state and the CPL.
kvm_require_cpl is even kind enough to inject the GP fault for us.
Signed-off-by: Kyle Huey <khuey@kylehuey.com> Reviewed-by: David Matlack <dmatlack@google.com>
[Return "1" from kvm_emulate_cpuid, it's not void. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vmm_exclusive=0 leads to KVM setting X86_CR4_VMXE always and calling
VMXON only when the vcpu is loaded. X86_CR4_VMXE is used as an
indication in cpu_emergency_vmxoff() (called on kdump) if VMXOFF has to be
called. This is obviously not the case if both are used independtly.
Calling VMXOFF without a previous VMXON will result in an exception.
In addition, X86_CR4_VMXE is used as a mean to test if VMX is already in
use by another VMM in hardware_enable(). So there can't really be
co-existance. If the other VMM is prepared for co-existance and does a
similar check, only one VMM can exist. If the other VMM is not prepared
and blindly sets/clears X86_CR4_VMXE, we will get inconsistencies with
X86_CR4_VMXE.
As we also had bug reports related to clearing of vmcs with vmm_exclusive=0
this seems to be pretty much untested. So let's better drop it.
While at it, directly move setting/clearing X86_CR4_VMXE into
kvm_cpu_vmxon/off.
Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Farhan Ali [Fri, 24 Feb 2017 21:12:56 +0000 (16:12 -0500)]
KVM: s390: Support keyless subset guest mode
If the KSS facility is available on the machine, we also make it
available for our KVM guests.
The KSS facility bypasses storage key management as long as the guest
does not issue a related instruction. When that happens, the control is
returned to the host, which has to turn off KSS for a guest vcpu
before retrying the instruction.
Signed-off-by: Corey S. McQuay <csmcquay@linux.vnet.ibm.com> Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Farhan Ali [Thu, 23 Feb 2017 18:39:17 +0000 (13:39 -0500)]
s390/sclp: Detect KSS facility
Let's detect the keyless subset facility.
Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Marc Zyngier [Thu, 20 Apr 2017 15:02:21 +0000 (16:02 +0100)]
ARM: KVM: Fix idmap stub entry when running Thumb-2 code
When entering the hyp stub implemented in the idmap, we try to
be mindful of the fact that we could be running a Thumb-2 kernel
by adding 1 to the address we compute. Unfortunately, the assembler
also knows about this trick, and has already generated an address
that has bit 0 set in the litteral pool.
Our superfluous correction ends up confusing the CPU entierely,
as we now branch to the stub in ARM mode instead of Thumb, and on
a possibly unaligned address for good measure. From that point,
nothing really good happens.
The obvious fix in to remove this stupid target PC correction.
Fixes: 6bebcecb6c5b ("ARM: KVM: Allow the main HYP code to use the init hyp stub implementation") Reported-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Thomas Huth [Wed, 5 Apr 2017 13:58:51 +0000 (15:58 +0200)]
KVM: PPC: Book3S PR: Do not fail emulation with mtspr/mfspr for unknown SPRs
According to the PowerISA 2.07, mtspr and mfspr should not always
generate an illegal instruction exception when being used with an
undefined SPR, but rather treat the instruction as a NOP or inject a
privilege exception in some cases, too - depending on the SPR number.
Also turn the printk here into a ratelimited print statement, so that
the guest can not flood the dmesg log of the host by issueing lots of
illegal mtspr/mfspr instruction here.
Signed-off-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
KVM: PPC: VFIO: Add in-kernel acceleration for VFIO
This allows the host kernel to handle H_PUT_TCE, H_PUT_TCE_INDIRECT
and H_STUFF_TCE requests targeted an IOMMU TCE table used for VFIO
without passing them to user space which saves time on switching
to user space and back.
This adds H_PUT_TCE/H_PUT_TCE_INDIRECT/H_STUFF_TCE handlers to KVM.
KVM tries to handle a TCE request in the real mode, if failed
it passes the request to the virtual mode to complete the operation.
If it a virtual mode handler fails, the request is passed to
the user space; this is not expected to happen though.
To avoid dealing with page use counters (which is tricky in real mode),
this only accelerates SPAPR TCE IOMMU v2 clients which are required
to pre-register the userspace memory. The very first TCE request will
be handled in the VFIO SPAPR TCE driver anyway as the userspace view
of the TCE table (iommu_table::it_userspace) is not allocated till
the very first mapping happens and we cannot call vmalloc in real mode.
If we fail to update a hardware IOMMU table unexpected reason, we just
clear it and move on as there is nothing really we can do about it -
for example, if we hot plug a VFIO device to a guest, existing TCE tables
will be mirrored automatically to the hardware and there is no interface
to report to the guest about possible failures.
This adds new attribute - KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE - to
the VFIO KVM device. It takes a VFIO group fd and SPAPR TCE table fd
and associates a physical IOMMU table with the SPAPR TCE table (which
is a guest view of the hardware IOMMU table). The iommu_table object
is cached and referenced so we do not have to look up for it in real mode.
This does not implement the UNSET counterpart as there is no use for it -
once the acceleration is enabled, the existing userspace won't
disable it unless a VFIO container is destroyed; this adds necessary
cleanup to the KVM_DEV_VFIO_GROUP_DEL handler.
This advertises the new KVM_CAP_SPAPR_TCE_VFIO capability to the user
space.
This adds real mode version of WARN_ON_ONCE() as the generic version
causes problems with rcu_sched. Since we testing what vmalloc_to_phys()
returns in the code, this also adds a check for already existing
vmalloc_to_phys() call in kvmppc_rm_h_put_tce_indirect().
This finally makes use of vfio_external_user_iommu_id() which was
introduced quite some time ago and was considered for removal.
Tests show that this patch increases transmission speed from 220MB/s
to 750..1020MB/s on 10Gb network (Chelsea CXGB3 10Gb ethernet card).
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
KVM: PPC: Use preregistered memory API to access TCE list
VFIO on sPAPR already implements guest memory pre-registration
when the entire guest RAM gets pinned. This can be used to translate
the physical address of a guest page containing the TCE list
from H_PUT_TCE_INDIRECT.
This makes use of the pre-registrered memory API to access TCE list
pages in order to avoid unnecessary locking on the KVM memory
reverse map as we know that all of guest memory is pinned and
we have a flat array mapping GPA to HPA which makes it simpler and
quicker to index into that array (even with looking up the
kernel page tables in vmalloc_to_phys) than it is to find the memslot,
lock the rmap entry, look up the user page tables, and unlock the rmap
entry. Note that the rmap pointer is initialized to NULL
where declared (not in this patch).
If a requested chunk of memory has not been preregistered, this will
fall back to non-preregistered case and lock rmap.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The guest view TCE tables are per KVM anyway (not per VCPU) so pass kvm*
there. This will be used in the following patches where we will be
attaching VFIO containers to LIOBNs via ioctl() to KVM (rather than
to VCPU).
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
KVM: PPC: Enable IOMMU_API for KVM_BOOK3S_64 permanently
It does not make much sense to have KVM in book3s-64 and
not to have IOMMU bits for PCI pass through support as it costs little
and allows VFIO to function on book3s KVM.
Having IOMMU_API always enabled makes it unnecessary to have a lot of
"#ifdef IOMMU_API" in arch/powerpc/kvm/book3s_64_vio*. With those
ifdef's we could have only user space emulated devices accelerated
(but not VFIO) which do not seem to be very useful.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
KVM: PPC: Reserve KVM_CAP_SPAPR_TCE_VFIO capability number
This adds a capability number for in-kernel support for VFIO on
SPAPR platform.
The capability will tell the user space whether in-kernel handlers of
H_PUT_TCE can handle VFIO-targeted requests or not. If not, the user space
must not attempt allocating a TCE table in the host kernel via
the KVM_CREATE_SPAPR_TCE KVM ioctl because in that case TCE requests
will not be passed to the user space which is desired action in
the situation like that.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
KVM: PPC: Align the table size to system page size
At the moment the userspace can request a table smaller than a page size
and this value will be stored as kvmppc_spapr_tce_table::size.
However the actual allocated size will still be aligned to the system
page size as alloc_page() is used there.
This aligns the table size up to the system page size. It should not
change the existing behaviour but when in-kernel TCE acceleration patchset
reaches the upstream kernel, this will allow small TCE tables be
accelerated as well: PCI IODA iommu_table allocator already aligns
the size and, without this patch, an IOMMU group won't attach to LIOBN
due to the mismatching table size.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
KVM: PPC: Book3S PR: Preserve storage control bits
PR KVM page fault handler performs eaddr to pte translation for a guest,
however kvmppc_mmu_book3s_64_xlate() does not preserve WIMG bits
(storage control) in the kvmppc_pte struct. If PR KVM is running as
a second level guest under HV KVM, and PR KVM tries inserting HPT entry,
this fails in HV KVM if it already has this mapping.
This preserves WIMG bits between kvmppc_mmu_book3s_64_xlate() and
kvmppc_mmu_map_page().
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
At the moment kvmppc_mmu_map_page() returns -1 if
mmu_hash_ops.hpte_insert() fails for any reason so the page fault handler
resumes the guest and it faults on the same address again.
This adds distinction to kvmppc_mmu_map_page() to return -EIO if
mmu_hash_ops.hpte_insert() failed for a reason other than full pteg.
At the moment only pSeries_lpar_hpte_insert() returns -2 if
plpar_pte_enter() failed with a code other than H_PTEG_FULL.
Other mmu_hash_ops.hpte_insert() instances can only fail with
-1 "full pteg".
With this change, if PR KVM fails to update HPT, it can signal
the userspace about this instead of returning to guest and having
the very same page fault over and over again.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Markus Elfring [Fri, 20 Jan 2017 15:30:18 +0000 (16:30 +0100)]
KVM: PPC: e500: Use kcalloc() in e500_mmu_host_init()
* A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kcalloc".
This issue was detected by using the Coccinelle software.
* Replace the specification of a data type by a pointer dereference
to make the corresponding size determination a bit safer according to
the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Paul Mackerras [Thu, 23 Mar 2017 00:55:16 +0000 (11:55 +1100)]
KVM: PPC: Add MMIO emulation for remaining floating-point instructions
For completeness, this adds emulation of the lfiwax and lfiwzx
instructions. With this, all floating-point load and store instructions
as of Power ISA V2.07 are emulated.
Previously, most of these would cause an emulation failure exit to
userspace, though ldu and lwa got treated incorrectly as ld, and
stdu got treated incorrectly as std.
This also tidies up some of the formatting and updates the comment
listing instructions that still need to be implemented.
With this, all integer loads and stores that are defined in the Power
ISA v2.07 are emulated, except for those that are permitted to trap
when used on cache-inhibited or write-through mappings (and which do
in fact trap on POWER8), that is, lmw/stmw, lswi/stswi, lswx/stswx,
lq/stq, and l[bhwdq]arx/st[bhwdq]cx.
KVM: PPC: Add MMIO emulation for stdx (store doubleword indexed)
This adds missing stdx emulation for emulated MMIO accesses by KVM
guests. This allows the Mellanox mlx5_core driver from recent kernels
to work when MMIO emulation is enforced by userspace.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Bin Lu [Tue, 21 Feb 2017 13:12:36 +0000 (21:12 +0800)]
KVM: PPC: Book3S: Add MMIO emulation for FP and VSX instructions
This patch provides the MMIO load/store emulation for instructions
of 'double & vector unsigned char & vector signed char & vector
unsigned short & vector signed short & vector unsigned int & vector
signed int & vector double '.
The instructions that this adds emulation for are:
Paul Mackerras [Wed, 22 Mar 2017 10:02:08 +0000 (21:02 +1100)]
KVM: PPC: Provide functions for queueing up FP/VEC/VSX unavailable interrupts
This provides functions that can be used for generating interrupts
indicating that a given functional unit (floating point, vector, or
VSX) is unavailable. These functions will be used in instruction
emulation code.
Marc Zyngier [Wed, 19 Apr 2017 11:15:26 +0000 (12:15 +0100)]
KVM: arm/arm64: vgic-v3: De-optimize VMCR save/restore when emulating a GICv2
When emulating a GICv2-on-GICv3, special care must be taken to only
save/restore VMCR_EL2 when ICC_SRE_EL1.SRE is cleared. Otherwise,
all Group-0 interrupts end-up being delivered as FIQ, which is
probably not what the guest expects, as demonstrated here with
an unhappy EFI:
FIQ Exception at 0x000000013BD21CC4
This means that we cannot perform the load/put trick when dealing
with VMCR_EL2 (because the host has SRE set), and we have to deal
with it in the world-switch.
Fortunately, this is not the most common case (modern guests should
be able to deal with GICv3 directly), and the performance is not worse
than what it was before the VMCR optimization.
Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Andrew Jones [Tue, 18 Apr 2017 15:59:58 +0000 (17:59 +0200)]
KVM: arm/arm64: fix races in kvm_psci_vcpu_on
Fix potential races in kvm_psci_vcpu_on() by taking the kvm->lock
mutex. In general, it's a bad idea to allow more than one PSCI_CPU_ON
to process the same target VCPU at the same time. One such problem
that may arise is that one PSCI_CPU_ON could be resetting the target
vcpu, which fills the entire sys_regs array with a temporary value
including the MPIDR register, while another looks up the VCPU based
on the MPIDR value, resulting in no target VCPU found. Resolves both
races found with the kvm-unit-tests/arm/psci unit test.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Reported-by: Levente Kurusa <lkurusa@redhat.com> Suggested-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Andrew Jones <drjones@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Christoffer Dall <cdall@linaro.org>
KVM: nVMX: fix AD condition when handling EPT violation
I have introduced this bug when applying and simplifying Paolo's patch
as we agreed on the list. The original was "x &= ~y; if (z) x |= y;".
Here is the story of a bad workflow:
A maintainer was already testing with the intended change, but it was
applied only to a testing repo on a different machine. When the time
to push tested patches to kvm/next came, he realized that this change
was missing and quickly added it to the maintenance repo, didn't test
again (because the change is trivial, right), and pushed the world to
fire.
Wanpeng Li [Tue, 11 Apr 2017 09:49:21 +0000 (02:49 -0700)]
x86/kvm: virt_xxx memory barriers instead of mandatory barriers
virt_xxx memory barriers are implemented trivially using the low-level
__smp_xxx macros, __smp_xxx is equal to a compiler barrier for strong
TSO memory model, however, mandatory barriers will unconditional add
memory barriers, this patch replaces the rmb() in kvm_steal_clock() by
virt_rmb().
Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM: x86: fix maintaining of kvm_clock stability on guest CPU hotplug
VCPU TSC synchronization is perfromed in kvm_write_tsc() when the TSC
value being set is within 1 second from the expected, as obtained by
extrapolating of the TSC in already synchronized VCPUs.
This is naturally achieved on all VCPUs at VM start and resume;
however on VCPU hotplug it is not: the newly added VCPU is created
with TSC == 0 while others are well ahead.
To compensate for that, consider host-initiated kvm_write_tsc() with
TSC == 0 a special case requiring synchronization regardless of the
current TSC on other VCPUs.
KVM: x86: don't take kvm->irq_lock when creating IRQCHIP
I don't see any reason any more for this lock, seemed to be used to protect
removal of kvm->arch.vpic / kvm->arch.vioapic when already partially
inititalized, now access is properly protected using kvm->arch.irqchip_mode
and this shouldn't be necessary anymore.
Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
It seemed like a nice idea to encapsulate access to kvm->arch.vpic. But
as the usage is already mixed, internal locks are taken outside of i8259.c
and grepping for "vpic" only is much easier, let's just get rid of
pic_irqchip().
Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM: x86: check against irqchip_mode in ioapic_in_kernel()
KVM_IRQCHIP_KERNEL implies a fully inititalized ioapic, while
kvm->arch.vioapic might temporarily be set but invalidated again if e.g.
setting of default routing fails when setting KVM_CREATE_IRQCHIP.
Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM: x86: check against irqchip_mode in pic_in_kernel()
Let's avoid checking against kvm->arch.vpic. We have kvm->arch.irqchip_mode
for that now.
KVM_IRQCHIP_KERNEL implies a fully inititalized pic, while kvm->arch.vpic
might temporarily be set but invalidated again if e.g. kvm_ioapic_init()
fails when setting KVM_CREATE_IRQCHIP. Although current users seem to be
fine, this avoids future bugs.
Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM: x86: check against irqchip_mode in kvm_set_routing_entry()
Let's replace the checks for pic_in_kernel() and ioapic_in_kernel() by
checks against irqchip_mode.
Also make sure that creation of any route is only possible if we have
an lapic in kernel (irqchip_in_kernel()) or if we are currently
inititalizing the irqchip.
This is necessary to switch pic_in_kernel() and ioapic_in_kernel() to
irqchip_mode, too.
Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM: s390: fix stale machine check data for guarded storage
When delivering a machine check the CPU state is "loaded", which
means that some registers are already in the host registers.
Before writing the register content into the machine check
save area, we must make sure that we save the content of the
registers into the data structures that are used for delivering
the machine check.
We already do the right thing for access, vector/floating point
registers, let's do the same for guarded storage.
Fixes: 4e0b1ab72b8a ("KVM: s390: gs support for kvm guests") Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
If the guest does not use the host register management, but it uses
the sdnx area, we must fill in a proper sdnxo value (address of sdnx
and the sdnxc).
Reported-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Merge tag 'kvm-s390-next-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux
From: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: features for 4.12
1. guarded storage support for guests
This contains an s390 base Linux feature branch that is necessary
to implement the KVM part
2. Provide an interface to implement adapter interruption suppression
which is necessary for proper zPCI support
3. Use more defines instead of numbers
4. Provide logging for lazy enablement of runtime instrumentation
KVM: arm/arm64: Advertise support for KVM_CAP_ARM_USER_IRQ
Now that we support both timers and PMU reporting interrupts
to userspace, we can advertise this support.
Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
KVM: arm/arm64: Report PMU overflow interrupts to userspace irqchip
When not using an in-kernel VGIC, but instead emulating an interrupt
controller in userspace, we should report the PMU overflow status to
that userspace interrupt controller using the KVM_CAP_ARM_USER_IRQ
feature.
Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Alexander Graf [Tue, 27 Sep 2016 19:08:06 +0000 (21:08 +0200)]
KVM: arm/arm64: Support arch timers with a userspace gic
If you're running with a userspace gic or other interrupt controller
(that is no vgic in the kernel), then you have so far not been able to
use the architected timers, because the output of the architected
timers, which are driven inside the kernel, was a kernel-only construct
between the arch timer code and the vgic.
This patch implements the new KVM_CAP_ARM_USER_IRQ feature, where we use a
side channel on the kvm_run structure, run->s.regs.device_irq_level, to
always notify userspace of the timer output levels when using a userspace
irqchip.
This works by ensuring that before we enter the guest, if the timer
output level has changed compared to what we last told userspace, we
don't enter the guest, but instead return to userspace to notify it of
the new level. If we are exiting, because of an MMIO for example, and
the level changed at the same time, the value is also updated and
userspace can sample the line as it needs. This is nicely achieved
simply always updating the timer_irq_level field after the main run
loop.
Note that the kvm_timer_update_irq trace event is changed to show the
host IRQ number for the timer instead of the guest IRQ number, because
the kernel no longer know which IRQ userspace wires up the timer signal
to.
Also note that this patch implements all required functionality but does
not yet advertise the capability.
Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Alexander Graf [Tue, 27 Sep 2016 19:08:05 +0000 (21:08 +0200)]
KVM: arm/arm64: Add ARM user space interrupt signaling ABI
We have 2 modes for dealing with interrupts in the ARM world. We can
either handle them all using hardware acceleration through the vgic or
we can emulate a gic in user space and only drive CPU IRQ pins from
there.
Unfortunately, when driving IRQs from user space, we never tell user
space about events from devices emulated inside the kernel, which may
result in interrupt line state changes, so we lose out on for example
timer and PMU events if we run with user space gic emulation.
Define an ABI to publish such device output levels to userspace.
Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Christoffer Dall [Tue, 27 Sep 2016 19:08:04 +0000 (21:08 +0200)]
KVM: arm/arm64: Cleanup the arch timer code's irqchip checking
Currently we check if we have an in-kernel irqchip and if the vgic was
properly implemented several places in the arch timer code. But, we
already predicate our enablement of the arm timers on having a valid
and initialized gic, so we can simply check if the timers are enabled or
not.
This also gets rid of the ugly "error that's not an error but used to
signal that the timer shouldn't poke the gic" construct we have.
Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Marc Zyngier [Mon, 3 Apr 2017 18:38:07 +0000 (19:38 +0100)]
arm/arm64: Add hyp-stub API documentation
In order to help people understanding the hyp-stub API that exists
between the host kernel and the hypervisor mode (whether a hypervisor
has been installed or not), let's document said API.
As with any form of documentation, I expect it to become obsolete
and completely misleading within 20 minutes after having being merged.
Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Marc Zyngier [Mon, 3 Apr 2017 18:38:03 +0000 (19:38 +0100)]
ARM: hyp-stub/KVM: Kill __hyp_get_vectors
Nobody is using __hyp_get_vectors anymore, so let's remove both
implementations (hyp-stub and KVM).
Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Marc Zyngier [Mon, 3 Apr 2017 18:38:02 +0000 (19:38 +0100)]
ARM: decompressor: Remove __hyp_get_vectors usage
When the compressed image needs to be relocated to avoid being
overwritten by the decompression process, we need to relocate
the hyp vectors as well so that we can find them once the
decompression has taken effect.
For that, we perform the following calculation:
u32 v = __hyp_get_vectors();
v += offset;
__hyp_set_vectors(v);
But we're guaranteed that the initial value of v as returned by
__hyp_get_vectors is always __hyp_stub_vectors, because we have
just set it by calling __hyp_stub_install.
So let's remove the use of __hyp_get_vectors, and directly use
__hyp_stub_vectors instead.
Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Marc Zyngier [Mon, 3 Apr 2017 18:38:01 +0000 (19:38 +0100)]
arm/arm64: KVM: Use HVC_RESET_VECTORS to reinit HYP mode
Instead of trying to compare the value given by __hyp_get_vectors(),
which doesn't offer any real guarantee to be the stub's address, use
HVC_RESET_VECTORS to make sure we're in a sane state to reinstall
KVM across PM events.
Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Marc Zyngier [Mon, 3 Apr 2017 18:37:59 +0000 (19:37 +0100)]
arm/arm64: KVM: Use __hyp_reset_vectors() directly
__cpu_reset_hyp_mode doesn't need to be passed any argument now,
as the hyp-stub implementations are self-contained, and is now
reduced to just calling __hyp_reset_vectors(). Let's drop the
wrapper and use the stub hypercall directly.
Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Marc Zyngier [Mon, 3 Apr 2017 18:37:58 +0000 (19:37 +0100)]
ARM: KVM: Gracefully handle hyp-stubs being restored from under our feet
Should kvm_reboot() be invoked while guest is running, an IPI
wil be issued, forcing the guest to exit and HYP being reset to
the stubs. We will then try to reenter the guest, only to get
an error (HVC_STUB_ERR).
This patch allows this case to be gracefully handled by exiting
the run loop.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
projects / karo-tx-linux.git / log