new_entry is reassigned a new value next line. So
it's redundant and remove it.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After commit d73eb57b80 (KVM: Boost vCPUs that are delivering interrupts), a
five years old bug is exposed. Running ebizzy benchmark in three 80 vCPUs VMs
on one 80 pCPUs Skylake server, a lot of rcu_sched stall warning splatting
in the VMs after stress testing:
INFO: rcu_sched detected stalls on CPUs/tasks: { 4 41 57 62 77} (detected by 15, t=60004 jiffies, g=899, c=898, q=15073)
Call Trace:
flush_tlb_mm_range+0x68/0x140
tlb_flush_mmu.part.75+0x37/0xe0
tlb_finish_mmu+0x55/0x60
zap_page_range+0x142/0x190
SyS_madvise+0x3cd/0x9c0
system_call_fastpath+0x1c/0x21
swait_active() sustains to be true before finish_swait() is called in
kvm_vcpu_block(), voluntarily preempted vCPUs are taken into account
by kvm_vcpu_on_spin() loop greatly increases the probability condition
kvm_arch_vcpu_runnable(vcpu) is checked and can be true, when APICv
is enabled the yield-candidate vCPU's VMCS RVI field leaks(by
vmx_sync_pir_to_irr()) into spinning-on-a-taken-lock vCPU's current
VMCS.
This patch fixes it by checking conservatively a subset of events.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: stable@vger.kernel.org
Fixes: 98f4a1467 (KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop)
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After reverting commit 240c35a378 (kvm: x86: Use task structs fpu field
for user), struct kvm_vcpu is 19456 bytes on my server, PAGE_ALLOC_COSTLY_ORDER(3)
is the order at which allocations are deemed costly to service. In serveless
scenario, one host can service hundreds/thoudands firecracker/kata-container
instances, howerver, new instance will fail to launch after memory is too
fragmented to allocate kvm_vcpu struct on host, this was observed in some
cloud provider product environments.
This patch dynamically allocates user_fpu, kvm_vcpu is 15168 bytes now on my
Skylake server.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When CPU raise #NPF on guest data access and guest CR4.SMAP=1, it is
possible that CPU microcode implementing DecodeAssist will fail
to read bytes of instruction which caused #NPF. This is AMD errata
1096 and it happens because CPU microcode reading instruction bytes
incorrectly attempts to read code as implicit supervisor-mode data
accesses (that is, just like it would read e.g. a TSS), which are
susceptible to SMAP faults. The microcode reads CS:RIP and if it is
a user-mode address according to the page tables, the processor
gives up and returns no instruction bytes. In this case,
GuestIntrBytes field of the VMCB on a VMEXIT will incorrectly
return 0 instead of the correct guest instruction bytes.
Current KVM code attemps to detect and workaround this errata, but it
has multiple issues:
1) It mistakenly checks if guest CR4.SMAP=0 instead of guest CR4.SMAP=1,
which is required for encountering a SMAP fault.
2) It assumes SMAP faults can only occur when guest CPL==3.
However, in case guest CR4.SMEP=0, the guest can execute an instruction
which reside in a user-accessible page with CPL<3 priviledge. If this
instruction raise a #NPF on it's data access, then CPU DecodeAssist
microcode will still encounter a SMAP violation. Even though no sane
OS will do so (as it's an obvious priviledge escalation vulnerability),
we still need to handle this semanticly correct in KVM side.
Note that (2) *is* a useful optimization, because CR4.SMAP=1 is an easy
triggerable condition and guests usually enable SMAP together with SMEP.
If the vCPU has CR4.SMEP=1, the errata could indeed be encountered onlt
at guest CPL==3; otherwise, the CPU would raise a SMEP fault to guest
instead of #NPF. We keep this condition to avoid false positives in
the detection of the errata.
In addition, to avoid future confusion and improve code readbility,
include details of the errata in code and not just in commit message.
Fixes: 05d5a48635 ("KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation)")
Cc: Singh Brijesh <brijesh.singh@amd.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Add support for chained PMU counters in guests
- Improve SError handling
- Handle Neoverse N1 erratum #1349291
- Allow side-channel mitigation status to be migrated
- Standardise most AArch64 system register accesses to msr_s/mrs_s
- Fix host MPIDR corruption on 32bit
-----BEGIN PGP SIGNATURE-----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=yfCs
-----END PGP SIGNATURE-----
Merge tag 'kvm-arm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm updates for 5.3
- Add support for chained PMU counters in guests
- Improve SError handling
- Handle Neoverse N1 erratum #1349291
- Allow side-channel mitigation status to be migrated
- Standardise most AArch64 system register accesses to msr_s/mrs_s
- Fix host MPIDR corruption on 32bit
On VMX, KVM currently does not re-enable irqs until after it has exited
the guest context. As a result, a tick that fires in the window between
VM-Exit and guest_exit_irqoff() will be accounted as system time. While
said window is relatively small, it's large enough to be problematic in
some configurations, e.g. if VM-Exits are consistently occurring a hair
earlier than the tick irq.
Intentionally toggle irqs back off so that guest_exit_irqoff() can be
used in lieu of guest_exit() in order to avoid the save/restore of flags
in guest_exit(). On my Haswell system, "nop; cli; sti" is ~6 cycles,
versus ~28 cycles for "pushf; pop <reg>; cli; push <reg>; popf".
Fixes: f2485b3e0c ("KVM: x86: use guest_exit_irqoff")
Reported-by: Wei Yang <w90p710@gmail.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow testing code for old processors that lack the next RIP save
feature, by disabling usage of the next_rip field.
Nested hypervisors however get the feature unconditionally.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This allows userspace to know which MSRs are supported by the hypervisor.
Unfortunately userspace must resort to tricks for everything except
MSR_IA32_VMX_VMFUNC (which was just added in the previous patch).
One possibility is to use the feature control MSR, which is tied to nested
VMX as well and is present on all KVM versions that support feature MSRs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Based on 1 normalized pattern(s):
this work is licensed under the terms of the gnu gpl version 2 see
the copying file in the top level directory
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 35 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Per commit 1b6269db3f ("KVM: VMX: Handle NMIs before enabling
interrupts and preemption"), NMIs are handled directly in vmx_vcpu_run()
to "make sure we handle NMI on the current cpu, and that we don't
service maskable interrupts before non-maskable ones". The other
exceptions handled by complete_atomic_exit(), e.g. async #PF and #MC,
have similar requirements, and are located there to avoid extra VMREADs
since VMX bins hardware exceptions and NMIs into a single exit reason.
Clean up the code and eliminate the vaguely named complete_atomic_exit()
by moving the interrupts-disabled exception and NMI handling into the
existing handle_external_intrs() callback, and rename the callback to
a more appropriate name. Rename VMexit handlers throughout so that the
atomic and non-atomic counterparts have similar names.
In addition to improving code readability, this also ensures the NMI
handler is run with the host's debug registers loaded in the unlikely
event that the user is debugging NMIs. Accuracy of the last_guest_tsc
field is also improved when handling NMIs (and #MCs) as the handler
will run after updating said field.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Naming cleanups. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
VMX can conditionally call kvm_{before,after}_interrupt() since KVM
always uses "ack interrupt on exit" and therefore explicitly handles
interrupts as opposed to blindly enabling irqs.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a wrapper to invoke kvm_arch_check_processor_compat() so that the
boilerplate ugliness of checking virtualization support on all CPUs is
hidden from the arch specific code. x86's implementation in particular
is quite heinous, as it unnecessarily propagates the out-param pattern
into kvm_x86_ops.
While the x86 specific issue could be resolved solely by changing
kvm_x86_ops, make the change for all architectures as returning a value
directly is prettier and technically more robust, e.g. s390 doesn't set
the out param, which could lead to subtle breakage in the (highly
unlikely) scenario where the out-param was not pre-initialized by the
caller.
Opportunistically annotate svm_check_processor_compat() with __init.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AVIC doorbell is used to notify a running vCPU that interrupts
has been injected into the vCPU AVIC backing page. Current logic
checks only if a VCPU is running before sending a doorbell.
However, the doorbell is not necessary if the destination
CPU is itself.
Add logic to check currently running CPU before sending doorbell.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Advance lapic timer tries to hidden the hypervisor overhead between the
host emulated timer fires and the guest awares the timer is fired. However,
it just hidden the time between apic_timer_fn/handle_preemption_timer ->
wait_lapic_expire, instead of the real position of vmentry which is
mentioned in the orignial commit d0659d946b ("KVM: x86: add option to
advance tscdeadline hrtimer expiration"). There is 700+ cpu cycles between
the end of wait_lapic_expire and before world switch on my haswell desktop.
This patch tries to narrow the last gap(wait_lapic_expire -> world switch),
it takes the real overhead time between apic_timer_fn/handle_preemption_timer
and before world switch into consideration when adaptively tuning timer
advancement. The patch can reduce 40% latency (~1600+ cycles to ~1000+ cycles
on a haswell desktop) for kvm-unit-tests/tscdeadline_latency when testing
busy waits.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 8c5fbf1a72 ("KVM/nSVM: Use the new mapping API for mapping guest
memory") broke nested SVM completely: kvm_vcpu_map()'s second parameter is
GFN so vmcb_gpa needs to be converted with gpa_to_gfn(), not the other way
around.
Fixes: 8c5fbf1a72 ("KVM/nSVM: Use the new mapping API for mapping guest memory")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Userspace can easily set up invalid processor state in such a way that
dmesg will be filled with VMCS or VMCB dumps. Disable this by default
using a module parameter.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Current logic does not allow VCPU to be loaded onto CPU with
APIC ID 255. This should be allowed since the host physical APIC ID
field in the AVIC Physical APIC table entry is an 8-bit value,
and APIC ID 255 is valid in system with x2APIC enabled.
Instead, do not allow VCPU load if the host APIC ID cannot be
represented by an 8-bit value.
Also, use the more appropriate AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK
instead of AVIC_MAX_PHYSICAL_ID_COUNT.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* POWER: support for direct access to the POWER9 XIVE interrupt controller,
memory and performance optimizations.
* x86: support for accessing memory not backed by struct page, fixes and refactoring
* Generic: dirty page tracking improvements
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
iQEcBAABAgAGBQJc3qV/AAoJEL/70l94x66Dn3QH/jX1Bn0P/RZAIt4w0SySklSg
PqxUKDyBQqB9vN9Qeb9jWXAKPH2CtM3+up/rz7oRnBWp7qA6vXcC/R/QJYAvzdXE
nklsR/oYCsflR1KdlVYuDvvPCPP2fLBU5zfN83OsaBQ8fNRkm3gN+N5XQ2SbXbLy
Mo9tybS4otY201UAC96e8N0ipwwyCRpDneQpLcl+F5nH3RBt63cVbs04O+70MXn7
eT4I+8K3+Go7LATzT8hglD21D/7uvE31qQb6yr5L33IfhU4GB51RZzBXTNaAdY8n
hT1rMrRkAMAFWYZPQDfoMadjWU3i5DIfstKjDxOr9oTfuOEp5Z+GvJwvVnUDg1I=
=D0+p
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- support for SVE and Pointer Authentication in guests
- PMU improvements
POWER:
- support for direct access to the POWER9 XIVE interrupt controller
- memory and performance optimizations
x86:
- support for accessing memory not backed by struct page
- fixes and refactoring
Generic:
- dirty page tracking improvements"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (155 commits)
kvm: fix compilation on aarch64
Revert "KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU"
kvm: x86: Fix L1TF mitigation for shadow MMU
KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible
KVM: PPC: Book3S: Remove useless checks in 'release' method of KVM device
KVM: PPC: Book3S HV: XIVE: Fix spelling mistake "acessing" -> "accessing"
KVM: PPC: Book3S HV: Make sure to load LPID for radix VCPUs
kvm: nVMX: Set nested_run_pending in vmx_set_nested_state after checks complete
tests: kvm: Add tests for KVM_SET_NESTED_STATE
KVM: nVMX: KVM_SET_NESTED_STATE - Tear down old EVMCS state before setting new state
tests: kvm: Add tests for KVM_CAP_MAX_VCPUS and KVM_CAP_MAX_CPU_ID
tests: kvm: Add tests to .gitignore
KVM: Introduce KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
KVM: Fix kvm_clear_dirty_log_protect off-by-(minus-)one
KVM: Fix the bitmap range to copy during clear dirty
KVM: arm64: Fix ptrauth ID register masking logic
KVM: x86: use direct accessors for RIP and RSP
KVM: VMX: Use accessors for GPRs outside of dedicated caching logic
KVM: x86: Omit caching logic for always-available GPRs
kvm, x86: Properly check whether a pfn is an MMIO or not
...
To facilitate additional options to get_user_pages_fast() change the
singular write parameter to be gup_flags.
This patch does not change any functionality. New functionality will
follow in subsequent patches.
Some of the get_user_pages_fast() call sites were unchanged because they
already passed FOLL_WRITE or 0 for the write parameter.
NOTE: It was suggested to change the ordering of the get_user_pages_fast()
arguments to ensure that callers were converted. This breaks the current
GUP call site convention of having the returned pages be the final
parameter. So the suggestion was rejected.
Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marshall <hubcap@omnibond.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use specific inline functions for RIP and RSP instead of
going through kvm_register_read and kvm_register_write,
which are quite a mouthful. kvm_rsp_read and kvm_rsp_write
did not exist, so add them.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Except for RSP and RIP, which are held in VMX's VMCS, GPRs are always
treated "available and dirtly" on both VMX and SVM, i.e. are
unconditionally loaded/saved immediately before/after VM-Enter/VM-Exit.
Eliminating the unnecessary caching code reduces the size of KVM by a
non-trivial amount, much of which comes from the most common code paths.
E.g. on x86_64, kvm_emulate_cpuid() is reduced from 342 to 182 bytes and
kvm_emulate_hypercall() from 1362 to 1143, with the total size of KVM
dropping by ~1000 bytes. With CONFIG_RETPOLINE=y, the numbers are even
more pronounced, e.g.: 353->182, 1418->1172 and well over 2000 bytes.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the new mapping API for mapping guest memory to avoid depending on
"struct page".
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
RSM emulation is currently broken on VMX when the interrupted guest has
CR4.VMXE=1. Stop dancing around the issue of HF_SMM_MASK being set when
loading SMSTATE into architectural state, e.g. by toggling it for
problematic flows, and simply clear HF_SMM_MASK prior to loading
architectural state (from SMRAM save state area).
Reported-by: Jon Doron <arilou@gmail.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Fixes: 5bea5123cb ("KVM: VMX: check nested state and CR4.VMXE against SMM")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
RSM emulation is currently broken on VMX when the interrupted guest has
CR4.VMXE=1. Rather than dance around the issue of HF_SMM_MASK being set
when loading SMSTATE into architectural state, ideally RSM emulation
itself would be reworked to clear HF_SMM_MASK prior to loading non-SMM
architectural state.
Ostensibly, the only motivation for having HF_SMM_MASK set throughout
the loading of state from the SMRAM save state area is so that the
memory accesses from GET_SMSTATE() are tagged with role.smm. Load
all of the SMRAM save state area from guest memory at the beginning of
RSM emulation, and load state from the buffer instead of reading guest
memory one-by-one.
This paves the way for clearing HF_SMM_MASK prior to loading state,
and also aligns RSM with the enter_smm() behavior, which fills a
buffer and writes SMRAM save state in a single go.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
guest xcr0 could leak into host when MCE happens in guest mode. Because
do_machine_check() could schedule out at a few places.
For example:
kvm_load_guest_xcr0
...
kvm_x86_ops->run(vcpu) {
vmx_vcpu_run
vmx_complete_atomic_exit
kvm_machine_check
do_machine_check
do_memory_failure
memory_failure
lock_page
In this case, host_xcr0 is 0x2ff, guest vcpu xcr0 is 0xff. After schedule
out, host cpu has guest xcr0 loaded (0xff).
In __switch_to {
switch_fpu_finish
copy_kernel_to_fpregs
XRSTORS
If any bit i in XSTATE_BV[i] == 1 and xcr0[i] == 0, XRSTORS will
generate #GP (In this case, bit 9). Then ex_handler_fprestore kicks in
and tries to reinitialize fpu by restoring init fpu state. Same story as
last #GP, except we get DOUBLE FAULT this time.
Cc: stable@vger.kernel.org
Signed-off-by: WANG Chao <chao.wang@ucloud.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
I noticed that apic test from kvm-unit-tests always hangs on my EPYC 7401P,
the hanging test nmi-after-sti is trying to deliver 30000 NMIs and tracing
shows that we're sometimes able to deliver a few but never all.
When we're trying to inject an NMI we may fail to do so immediately for
various reasons, however, we still need to inject it so enable_nmi_window()
arms nmi_singlestep mode. #DB occurs as expected, but we're not checking
for pending NMIs before entering the guest and unless there's a different
event to process, the NMI will never get delivered.
Make KVM_REQ_EVENT request on the vCPU from db_interception() to make sure
pending NMIs are checked and possibly injected.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Only clear the valid bit when invalidate logical APIC id entry.
The current logic clear the valid bit, but also set the rest of
the bits (including reserved bits) to 1.
Fixes: 98d90582be ('svm: Fix AVIC DFR and LDR handling')
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This reverts commit bb218fbcfa.
As Oren Twaig pointed out the old discussion:
https://patchwork.kernel.org/patch/8292231/
that the change coud potentially cause an extra IPI to be sent to
the destination vcpu because the AVIC hardware already set the IRR bit
before the incomplete IPI #VMEXIT with id=1 (target vcpu is not running).
Since writting to ICR and ICR2 will also set the IRR. If something triggers
the destination vcpu to get scheduled before the emulation finishes, then
this could result in an additional IPI.
Also, the issue mentioned in the commit bb218fbcfa was misdiagnosed.
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Oren Twaig <oren@scalemp.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This ensures that the address and length provided to DBG_DECRYPT and
DBG_ENCRYPT do not cause an overflow.
At the same time, pass the actual number of pages pinned in memory to
sev_unpin_memory() as a cleanup.
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
get_num_contig_pages() could potentially overflow int so make its type
consistent with its usage.
Reported-by: Cfir Cohen <cfir@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Errata#1096:
On a nested data page fault when CR.SMAP=1 and the guest data read
generates a SMAP violation, GuestInstrBytes field of the VMCB on a
VMEXIT will incorrectly return 0h instead the correct guest
instruction bytes .
Recommend Workaround:
To determine what instruction the guest was executing the hypervisor
will have to decode the instruction at the instruction pointer.
The recommended workaround can not be implemented for the SEV
guest because guest memory is encrypted with the guest specific key,
and instruction decoder will not be able to decode the instruction
bytes. If we hit this errata in the SEV guest then log the message
and request a guest shutdown.
Reported-by: Venkatesh Srinivas <venkateshs@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There are many KVM kernel memory allocations which are tied to the life of
the VM process and should be charged to the VM process's cgroup. If the
allocations aren't tied to the process, the OOM killer will not know
that killing the process will free the associated kernel memory.
Add __GFP_ACCOUNT flags to many of the allocations which are not yet being
charged to the VM process's cgroup.
Tested:
Ran all kvm-unit-tests on a 64 bit Haswell machine, the patch
introduced no new failures.
Ran a kernel memory accounting test which creates a VM to touch
memory and then checks that the kernel memory allocated for the
process is within certain bounds.
With this patch we account for much more of the vmalloc and slab memory
allocated for the VM.
Signed-off-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function svm_refresh_apicv_exec_ctrl() always returning prematurely
as kvm_vcpu_apicv_active() always return false when calling from
the function arch/x86/kvm/x86.c:kvm_vcpu_deactivate_apicv().
This is because the apicv_active is set to false just before calling
refresh_apicv_exec_ctrl().
Also, we need to mark VMCB_AVIC bit as dirty instead of VMCB_INTR.
So, fix svm_refresh_apicv_exec_ctrl() to properly deactivate AVIC.
Fixes: 67034bb9dd ('KVM: SVM: Add irqchip_split() checks before enabling AVIC')
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Current SVM AVIC driver makes two incorrect assumptions:
1. APIC LDR register cannot be zero
2. APIC DFR for all vCPUs must be the same
LDR=0 means the local APIC does not support logical destination mode.
Therefore, the driver should mark any previously assigned logical APIC ID
table entry as invalid, and return success. Also, DFR is specific to
a particular local APIC, and can be different among all vCPUs
(as observed on Windows 10).
These incorrect assumptions cause Windows 10 and FreeBSD VMs to fail
to boot with AVIC enabled. So, instead of flush the whole logical APIC ID
table, handle DFR and LDR for each vCPU independently.
Fixes: 18f40c53e1 ('svm: Add VMEXIT handlers for AVIC')
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Julian Stecklina <jsteckli@amazon.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/x86/kvm/lapic.c:1037:27: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/lapic.c:1876:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/hyperv.c:1637:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/svm.c:4396:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/mmu.c:4372:36: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/x86.c:3835:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/x86.c:7938:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/vmx/vmx.c:2015:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/x86/kvm/vmx/vmx.c:1773:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
Warning level 3 was used: -Wimplicit-fallthrough=3
This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm-unit-tests' eventinj "NMI failing on IDT" test results in NMI being
delivered to the host (L1) when it's running nested. The problem seems to
be: svm_complete_interrupts() raises 'nmi_injected' flag but later we
decide to reflect EXIT_NPF to L1. The flag remains pending and we do NMI
injection upon entry so it got delivered to L1 instead of L2.
It seems that VMX code solves the same issue in prepare_vmcs12(), this was
introduced with code refactoring in commit 5f3d579997 ("KVM: nVMX: Rework
event injection and recovery").
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In case of incomplete IPI with invalid interrupt type, the current
SVM driver does not properly emulate the IPI, and fails to boot
FreeBSD guests with multiple vcpus when enabling AVIC.
Fix this by update APIC ICR high/low registers, which also
emulate sending the IPI.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Print warning message when IPI target ID is invalid due to one of
the following reasons:
* In logical mode: cluster > max_cluster (64)
* In physical mode: target > max_physical (512)
* Address is not present in the physical or logical ID tables
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
By code inspection, it was found that multiple calls to KVM_SEV_INIT
could deplete asid bits and overwrite kvm_sev_info's regions_list.
Multiple calls to KVM_SVM_INIT is not likely to occur with QEMU, but this
should likely be fixed anyway.
This code is serialized by kvm->lock.
Fixes: 1654efcbc4 ("KVM: SVM: Add KVM_SEV_INIT command")
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
single-stepping fixes, improved tracing, various timer and vGIC
fixes
* x86: Processor Tracing virtualization, STIBP support, some correctness fixes,
refactorings and splitting of vmx.c, use the Hyper-V range TLB flush hypercall,
reduce order of vcpu struct, WBNOINVD support, do not use -ftrace for __noclone
functions, nested guest support for PAUSE filtering on AMD, more Hyper-V
enlightenments (direct mode for synthetic timers)
* PPC: nested VFIO
* s390: bugfixes only this time
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
iQEcBAABAgAGBQJcH0vFAAoJEL/70l94x66Dw/wH/2FZp1YOM5OgiJzgqnXyDbyf
dNEfWo472MtNiLsuf+ZAfJojVIu9cv7wtBfXNzW+75XZDfh/J88geHWNSiZDm3Fe
aM4MOnGG0yF3hQrRQyEHe4IFhGFNERax8Ccv+OL44md9CjYrIrsGkRD08qwb+gNh
P8T/3wJEKwUcVHA/1VHEIM8MlirxNENc78p6JKd/C7zb0emjGavdIpWFUMr3SNfs
CemabhJUuwOYtwjRInyx1y34FzYwW3Ejuc9a9UoZ+COahUfkuxHE8u+EQS7vLVF6
2VGVu5SA0PqgmLlGhHthxLqVgQYo+dB22cRnsLtXlUChtVAq8q9uu5sKzvqEzuE=
=b4Jx
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- selftests improvements
- large PUD support for HugeTLB
- single-stepping fixes
- improved tracing
- various timer and vGIC fixes
x86:
- Processor Tracing virtualization
- STIBP support
- some correctness fixes
- refactorings and splitting of vmx.c
- use the Hyper-V range TLB flush hypercall
- reduce order of vcpu struct
- WBNOINVD support
- do not use -ftrace for __noclone functions
- nested guest support for PAUSE filtering on AMD
- more Hyper-V enlightenments (direct mode for synthetic timers)
PPC:
- nested VFIO
s390:
- bugfixes only this time"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits)
KVM: x86: Add CPUID support for new instruction WBNOINVD
kvm: selftests: ucall: fix exit mmio address guessing
Revert "compiler-gcc: disable -ftracer for __noclone functions"
KVM: VMX: Move VM-Enter + VM-Exit handling to non-inline sub-routines
KVM: VMX: Explicitly reference RCX as the vmx_vcpu pointer in asm blobs
KVM: x86: Use jmp to invoke kvm_spurious_fault() from .fixup
MAINTAINERS: Add arch/x86/kvm sub-directories to existing KVM/x86 entry
KVM/x86: Use SVM assembly instruction mnemonics instead of .byte streams
KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()
KVM/MMU: Flush tlb directly in kvm_set_pte_rmapp()
KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()
KVM: Make kvm_set_spte_hva() return int
KVM: Replace old tlb flush function with new one to flush a specified range.
KVM/MMU: Add tlb flush with range helper function
KVM/VMX: Add hv tlb range flush support
x86/hyper-v: Add HvFlushGuestAddressList hypercall support
KVM: Add tlb_remote_flush_with_range callback in kvm_x86_ops
KVM: x86: Disable Intel PT when VMXON in L1 guest
KVM: x86: Set intercept for Intel PT MSRs read/write
KVM: x86: Implement Intel PT MSRs read/write emulation
...
Recently the minimum required version of binutils was changed to 2.20,
which supports all SVM instruction mnemonics. The patch removes
all .byte #defines and uses real instruction mnemonics instead.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Expose Intel Processor Trace to guest only when
the PT works in Host-Guest mode.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, the nested guest's PAUSE intercept intentions are not being
honored. Instead, since the L0 hypervisor's pause_filter_count and
pause_filter_thresh values are still in place, these values are used
instead of those programmed in the VMCB by the L1 hypervisor.
To honor the desired PAUSE intercept support of the L1 hypervisor, the L0
hypervisor must use the PAUSE filtering fields of the L1 hypervisor. This
requires saving and restoring of both the L0 and L1 hypervisor's PAUSE
filtering fields.
Signed-off-by: William Tambe <william.tambe@amd.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
AMD doesn't seem to implement MSR_IA32_MCG_EXT_CTL and svm code in kvm
knows nothing about it, however, this MSR is among emulated_msrs and
thus returned with KVM_GET_MSR_INDEX_LIST. The consequent KVM_GET_MSRS,
of course, fails.
Report the MSR as unsupported to not confuse userspace.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Recent optimizations in MMU code broke nested SVM with NPT in L1
completely: when we do nested_svm_{,un}init_mmu_context() we want
to switch from TDP MMU to shadow MMU, both init_kvm_tdp_mmu() and
kvm_init_shadow_mmu() check if re-configuration is needed by looking
at cache source data. The data, however, doesn't change - it's only
the type of the MMU which changes. We end up not re-initializing
guest MMU as shadow and everything goes off the rails.
The issue could have been fixed by putting MMU type into extended MMU
role but this is not really needed. We can just split root and guest MMUs
the exact same way we did for nVMX, their types never change in the
lifetime of a vCPU.
There is still room for improvement: currently, we reset all MMU roots
when switching from L1 to L2 and back and this is not needed.
Fixes: 7dcd575520 ("x86/kvm/mmu: check if tdp/shadow MMU reconfiguration is needed")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Previously, the guest_fpu field was embedded in the kvm_vcpu_arch
struct. Unfortunately, the field is quite large, (e.g., 4352 bytes on my
current setup). This bloats the kvm_vcpu_arch struct for x86 into an
order 3 memory allocation, which can become a problem on overcommitted
machines. Thus, this patch moves the fpu state outside of the
kvm_vcpu_arch struct.
With this patch applied, the kvm_vcpu_arch struct is reduced to 15168
bytes for vmx on my setup when building the kernel with kvmconfig.
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The upcoming KVM_GET_SUPPORTED_HV_CPUID ioctl will need to return
Enlightened VMCS version in HYPERV_CPUID_NESTED_FEATURES.EAX when
it was enabled.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For some reason, kvm_x86_ops->write_l1_tsc_offset() skipped trace
of change to active TSC offset in case vCPU is in guest-mode.
This patch changes write_l1_tsc_offset() behavior to trace any change
to active TSC offset to aid debugging. The VMX code is changed to
look more similar to SVM, which is in my opinion nicer.
Based on a patch by Liran Alon.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Previously, we only called indirect_branch_prediction_barrier on the
logical CPU that freed a vmcb. This function should be called on all
logical CPUs that last loaded the vmcb in question.
Fixes: 15d4507152 ("KVM/x86: Add IBPB support")
Reported-by: Neel Natu <neelnatu@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
