In order to enable userspace PIC support, the userspace PIC needs to
be able to inject local interrupts even when the APICs are in the
kernel.
KVM_INTERRUPT now supports sending local interrupts to an APIC when
APICs are in the kernel.
The ready_for_interrupt_request flag is now only set when the CPU/APIC
will immediately accept and inject an interrupt (i.e. APIC has not
masked the PIC).
When the PIC wishes to initiate an INTA cycle with, say, CPU0, it
kicks CPU0 out of the guest, and renedezvous with CPU0 once it arrives
in userspace.
When the CPU/APIC unmasks the PIC, a KVM_EXIT_IRQ_WINDOW_OPEN is
triggered, so that userspace has a chance to inject a PIC interrupt
if it had been pending.
Overall, this design can lead to a small number of spurious userspace
renedezvous. In particular, whenever the PIC transistions from low to
high while it is masked and whenever the PIC becomes unmasked while
it is low.
Note: this does not buffer more than one local interrupt in the
kernel, so the VMM needs to enter the guest in order to complete
interrupt injection before injecting an additional interrupt.
Compiles for x86.
Can pass the KVM Unit Tests.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to support a userspace IOAPIC interacting with an in kernel
APIC, the EOI exit bitmaps need to be configurable.
If the IOAPIC is in userspace (i.e. the irqchip has been split), the
EOI exit bitmaps will be set whenever the GSI Routes are configured.
In particular, for the low MSI routes are reservable for userspace
IOAPICs. For these MSI routes, the EOI Exit bit corresponding to the
destination vector of the route will be set for the destination VCPU.
The intention is for the userspace IOAPICs to use the reservable MSI
routes to inject interrupts into the guest.
This is a slight abuse of the notion of an MSI Route, given that MSIs
classically bypass the IOAPIC. It might be worthwhile to add an
additional route type to improve clarity.
Compile tested for Intel x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Adds KVM_EXIT_IOAPIC_EOI which allows the kernel to EOI
level-triggered IOAPIC interrupts.
Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs
to be informed (which is identical to the EOI_EXIT_BITMAP field used
by modern x86 processors, but can also be used to elide kvm IOAPIC EOI
exits on older processors).
[Note: A prototype using ResampleFDs found that decoupling the EOI
from the VCPU's thread made it possible for the VCPU to not see a
recent EOI after reentering the guest. This does not match real
hardware.]
Compile tested for Intel x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
First patch in a series which enables the relocation of the
PIC/IOAPIC to userspace.
Adds capability KVM_CAP_SPLIT_IRQCHIP;
KVM_CAP_SPLIT_IRQCHIP enables the construction of LAPICs without the
rest of the irqchip.
Compile tested for x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Suggested-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We can reuse the algorithm that computes the EOI exit bitmap to figure
out which vectors are handled by the IOAPIC. The only difference
between the two is for edge-triggered interrupts other than IRQ8
that have no notifiers active; however, the IOAPIC does not have to
do anything special for these interrupts anyway.
This again limits the interactions between the IOAPIC and the LAPIC,
making it easier to move the former to userspace.
Inspired by a patch from Steve Rutherford.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This merges a cleanup of asm/apic.h, which is needed by the KVM patches
to support VT-d posted interrupts.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some CONFIG_X86_X2APIC functions, especially x2apic_enabled(), are not
declared if !CONFIG_X86_LOCAL_APIC. However, the same stubs that work
for !CONFIG_X86_X2APIC are okay even if there is no local APIC support
at all.
Avoid the introduction of #ifdefs by moving the x2apic declarations
completely outside the CONFIG_X86_LOCAL_APIC block. (Unfortunately,
diff generation messes up the actual change that this patch makes).
There is no semantic change because CONFIG_X86_X2APIC depends on
CONFIG_X86_LOCAL_APIC.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Feng Wu <feng.wu@intel.com>
Link: http://lkml.kernel.org/r/1443435991-35750-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
HYPERVISOR_memory_op() is defined to return an "int" value. This is
wrong, as the Xen hypervisor will return "long".
The sub-function XENMEM_maximum_reservation returns the maximum
number of pages for the current domain. An int will overflow for a
domain configured with 8TB of memory or more.
Correct this by using the correct type.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Shifting pvclock_vcpu_time_info.system_time on write to KVM system time
MSR is a change of ABI. Probably only 2.6.16 based SLES 10 breaks due
to its custom enhancements to kvmclock, but KVM never declared the MSR
only for one-shot initialization. (Doc says that only one write is
needed.)
This reverts commit b7e60c5aed.
And adds a note to the definition of PVCLOCK_COUNTS_FROM_ZERO.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull perf fixes from Thomas Gleixner:
"Another pile of fixes for perf:
- Plug overflows and races in the core code
- Sanitize the flow of the perf syscall so we error out before
handling the more complex and hard to undo setups
- Improve and fix Broadwell and Skylake hardware support
- Revert a fix which broke what it tried to fix in perf tools
- A couple of smaller fixes in various places of perf tools"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix copying of /proc/kcore
perf intel-pt: Remove no_force_psb from documentation
perf probe: Use existing routine to look for a kernel module by dso->short_name
perf/x86: Change test_aperfmperf() and test_intel() to static
tools lib traceevent: Fix string handling in heterogeneous arch environments
perf record: Avoid infinite loop at buildid processing with no samples
perf: Fix races in computing the header sizes
perf: Fix u16 overflows
perf: Restructure perf syscall point of no return
perf/x86/intel: Fix Skylake FRONTEND MSR extrareg mask
perf/x86/intel/pebs: Add PEBS frontend profiling for Skylake
perf/x86/intel: Make the CYCLE_ACTIVITY.* constraint on Broadwell more specific
perf tools: Bool functions shouldn't return -1
tools build: Add test for presence of __get_cpuid() gcc builtin
tools build: Add test for presence of numa_num_possible_cpus() in libnuma
Revert "perf symbols: Fix mismatched declarations for elf_getphdrnum"
perf stat: Fix per-pkg event reporting bug
Pull KVM fixes from Paolo Bonzini:
"AMD fixes for bugs introduced in the 4.2 merge window, and a few PPC
bug fixes too"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: disable halt_poll_ns as default for s390x
KVM: x86: fix off-by-one in reserved bits check
KVM: x86: use correct page table format to check nested page table reserved bits
KVM: svm: do not call kvm_set_cr0 from init_vmcb
KVM: x86: trap AMD MSRs for the TSeg base and mask
KVM: PPC: Book3S: Take the kvm->srcu lock in kvmppc_h_logical_ci_load/store()
KVM: PPC: Book3S HV: Pass the correct trap argument to kvmhv_commence_exit
KVM: PPC: Book3S HV: Fix handling of interrupted VCPUs
kvm: svm: reset mmu on VCPU reset
We observed some performance degradation on s390x with dynamic
halt polling. Until we can provide a proper fix, let's enable
halt_poll_ns as default only for supported architectures.
Architectures are now free to set their own halt_poll_ns
default value.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This reinstates the following commit:
2c7577a758 ("sched/x86_64: Don't save flags on context switch")
which was reverted in:
512255a2ad ("Revert 'sched/x86_64: Don't save flags on context switch'")
Historically, Linux has always saved and restored EFLAGS across
context switches. As far as I know, the only reason to do this
is because of the NT flag. In particular, if something calls
switch_to() with the NT flag set, then we don't want to leak the
NT flag into a different task that might try to IRET and fail
because NT is set.
Before this commit:
8c7aa698ba ("x86_64, entry: Filter RFLAGS.NT on entry from userspace")
we could run system call bodies with NT set. This would be a DoS or possibly
privilege escalation hole if scheduling in such a system call would leak
NT into a different task.
Importantly, we don't need to worry about NT being set while
preemptible or across page faults. The only way we can schedule
due to preemption or a page fault is in an interrupt entry that
nests inside the SYSENTER prologue. The CPU will clear NT when
entering through an interrupt gate, so we won't schedule with NT
set.
The only other interesting flags are IOPL and AC. Allowing
switch_to() to change IOPL has no effect, as the value loaded
during kernel execution doesn't matter at all except between a
SYSENTER entry and the subsequent PUSHF, and anythign that
interrupts in that window will restore IOPL on return.
If we call __switch_to() with AC set, we have bigger problems.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/d4440fdc2a89247bffb7c003d2a9a2952bd46827.1441146105.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In not-instrumented code KASAN replaces instrumented memset/memcpy/memmove
with not-instrumented analogues __memset/__memcpy/__memove.
However, on x86 the EFI stub is not linked with the kernel. It uses
not-instrumented mem*() functions from arch/x86/boot/compressed/string.c
So we don't replace them with __mem*() variants in EFI stub.
On ARM64 the EFI stub is linked with the kernel, so we should replace
mem*() functions with __mem*(), because the EFI stub runs before KASAN
sets up early shadow.
So let's move these #undef mem* into arch's asm/efi.h which is also
included by the EFI stub.
Also, this will fix the warning in 32-bit build reported by kbuild test
robot:
efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy'
[akpm@linux-foundation.org: use 80 cols in comment]
Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Reported-by: Fengguang Wu <fengguang.wu@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These have roughly the same purpose as the SMRR, which we do not need
to implement in KVM. However, Linux accesses MSR_K8_TSEG_ADDR at
boot, which causes problems when running a Xen dom0 under KVM.
Just return 0, meaning that processor protection of SMRAM is not
in effect.
Reported-by: M A Young <m.a.young@durham.ac.uk>
Cc: stable@vger.kernel.org
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull KVM fixes from Paolo Bonzini:
"Mostly stable material, a lot of ARM fixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
sched: access local runqueue directly in single_task_running
arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS'
arm64: KVM: Remove all traces of the ThumbEE registers
arm: KVM: Disable virtual timer even if the guest is not using it
arm64: KVM: Disable virtual timer even if the guest is not using it
arm/arm64: KVM: vgic: Check for !irqchip_in_kernel() when mapping resources
KVM: s390: Replace incorrect atomic_or with atomic_andnot
arm: KVM: Fix incorrect device to IPA mapping
arm64: KVM: Fix user access for debug registers
KVM: vmx: fix VPID is 0000H in non-root operation
KVM: add halt_attempted_poll to VCPU stats
kvm: fix zero length mmio searching
kvm: fix double free for fast mmio eventfd
kvm: factor out core eventfd assign/deassign logic
kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd
KVM: make the declaration of functions within 80 characters
KVM: arm64: add workaround for Cortex-A57 erratum #852523
KVM: fix polling for guest halt continued even if disable it
arm/arm64: KVM: Fix PSCI affinity info return value for non valid cores
arm64: KVM: set {v,}TCR_EL2 RES1 bits
...
Pull x86 fixes from Ingo Molnar:
- misc fixes all around the map
- block non-root vm86(old) if mmap_min_addr != 0
- two small debuggability improvements
- removal of obsolete paravirt op
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/platform: Fix Geode LX timekeeping in the generic x86 build
x86/apic: Serialize LVTT and TSC_DEADLINE writes
x86/ioapic: Force affinity setting in setup_ioapic_dest()
x86/paravirt: Remove the unused pv_time_ops::get_tsc_khz method
x86/ldt: Fix small LDT allocation for Xen
x86/vm86: Fix the misleading CONFIG_VM86 Kconfig help text
x86/cpu: Print family/model/stepping in hex
x86/vm86: Block non-root vm86(old) if mmap_min_addr != 0
x86/alternatives: Make optimize_nops() interrupt safe and synced
x86/mm/srat: Print non-volatile flag in SRAT
x86/cpufeatures: Enable cpuid for Intel SHA extensions
Pull locking fixes from Ingo Molnar:
"Spinlock performance regression fix, plus documentation fixes"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/static_keys: Fix up the static keys documentation
locking/qspinlock/x86: Only emit the test-and-set fallback when building guest support
locking/qspinlock/x86: Fix performance regression under unaccelerated VMs
locking/static_keys: Fix a silly typo
This new statistic can help diagnosing VCPUs that, for any reason,
trigger bad behavior of halt_poll_ns autotuning.
For example, say halt_poll_ns = 480000, and wakeups are spaced exactly
like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes
10+20+40+80+160+320+480 = 1110 microseconds out of every
479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then
is consuming about 30% more CPU than it would use without
polling. This would show as an abnormally high number of
attempted polling compared to the successful polls.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com<
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There are two concepts that have some confusing naming:
1. Extended State Component numbers (currently called
XFEATURE_BIT_*)
2. Extended State Component masks (currently called XSTATE_*)
The numbers are (currently) from 0-9. State component 3 is the
bounds registers for MPX, for instance.
But when we want to enable "state component 3", we go set a bit
in XCR0. The bit we set is 1<<3. We can check to see if a
state component feature is enabled by looking at its bit.
The current 'xfeature_bit's are at best xfeature bit _numbers_.
Calling them bits is at best inconsistent with ending the enum
list with 'XFEATURES_NR_MAX'.
This patch renames the enum to be 'xfeature'. These also
happen to be what the Intel documentation calls a "state
component".
We also want to differentiate these from the "XSTATE_*" macros.
The "XSTATE_*" macros are a mask, and we rename them to match.
These macros are reasonably widely used so this patch is a
wee bit big, but this really is just a rename.
The only non-mechanical part of this is the
s/XSTATE_EXTEND_MASK/XFEATURE_MASK_EXTEND/
We need a better name for it, but that's another patch.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: dave@sr71.net
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150902233126.38653250@viggo.jf.intel.com
[ Ported to v4.3-rc1. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The original purpose of XSTATE_RESERVE was to carve out space
to store all of the possible extended state components that
get saved with the XSAVE instruction(s).
However, we are now almost entirely dynamically allocating
the buffers we use for XSAVE by placing them at the end of
the task_struct and them sizing them at boot. The one
exception for that is the init_task.
The maximum extended state component size that we have today
is on systems with space for AVX-512 and Memory Protection
Keys: 2696 bytes. We have reserved a PAGE_SIZE buffer in
the init_task via fpregs_state->__padding.
This check ensures that even if the component sizes or
layout were changed (which we do not expect), that we will
still not overflow the init_task's buffer.
In the case that we detect we might overflow the buffer,
we completely disable XSAVE support in the kernel and try
to boot as if we had 'legacy x87 FPU' support in place.
This is a crippled state without any of the XSAVE-enabled
features (MPX, AVX, etc...). But, it at least let us
boot safely.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: dave@sr71.net
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150902233125.D948D475@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
UV: NMI: insert this_cpu_read accessor function on uv_hub_nmi.
On SGI UV systems a 'power nmi' command from the CMC causes
all processors to drop into uv_handle_nmi(). With the 4.0
kernel this results in
BUG: unable to handle kernel paging request
The bug is caused by the current code trying to use the PER_CPU
variable uv_cpu_nmi.hub without an appropriate accessor
function. That oversight occurred in
commit e16321709c ("uv: Replace __get_cpu_var")
Author: Christoph Lameter <cl@linux.com>
Date: Sun Aug 17 12:30:41 2014 -0500
This patch inserts this_cpu_read() in the uv_hub_nmi macro
restoring the intended functionality.
Signed-off-by: George Beshers <gbeshers@sgi.com>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Hedi Berriche <hedi@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge third patch-bomb from Andrew Morton:
- even more of the rest of MM
- lib/ updates
- checkpatch updates
- small changes to a few scruffy filesystems
- kmod fixes/cleanups
- kexec updates
- a dma-mapping cleanup series from hch
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (81 commits)
dma-mapping: consolidate dma_set_mask
dma-mapping: consolidate dma_supported
dma-mapping: cosolidate dma_mapping_error
dma-mapping: consolidate dma_{alloc,free}_noncoherent
dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}
mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()
mm: make sure all file VMAs have ->vm_ops set
mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
mm: mark most vm_operations_struct const
namei: fix warning while make xmldocs caused by namei.c
ipc: convert invalid scenarios to use WARN_ON
zlib_deflate/deftree: remove bi_reverse()
lib/decompress_unlzma: Do a NULL check for pointer
lib/decompressors: use real out buf size for gunzip with kernel
fs/affs: make root lookup from blkdev logical size
sysctl: fix int -> unsigned long assignments in INT_MIN case
kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo
kexec: align crash_notes allocation to make it be inside one physical page
kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
kexec: split kexec_load syscall from kexec core code
...
Pull xen terminology fixes from David Vrabel:
"Use the correct GFN/BFN terms more consistently"
* tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn
xen/privcmd: Further s/MFN/GFN/ clean-up
hvc/xen: Further s/MFN/GFN clean-up
video/xen-fbfront: Further s/MFN/GFN clean-up
xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn
xen: Use correctly the Xen memory terminologies
arm/xen: implement correctly pfn_to_mfn
xen: Make clear that swiotlb and biomerge are dealing with DMA address
