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Use vmx_get_rflags() instead of manually reading vmcs.GUEST_RFLAGS when
querying RFLAGS.IF so that multiple checks against interrupt blocking in
a single run loop only require a single VMREAD.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-14-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Use vmx_interrupt_blocked() instead of bouncing through
vmx_interrupt_allowed() when handling edge cases in vmx_handle_exit().
The nested_run_pending check in vmx_interrupt_allowed() should never
evaluate true in the VM-Exit path.
Hoist the WARN in handle_invalid_guest_state() up to vmx_handle_exit()
to enforce the above assumption for the !enable_vnmi case, and to detect
any other potential bugs with nested VM-Enter.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-12-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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WARN if a pending exception is coincident with an injected exception
before calling check_nested_events() so that the WARN will fire even if
inject_pending_event() bails early because check_nested_events() detects
the conflict. Bailing early isn't problematic (quite the opposite), but
suppressing the WARN is undesirable as it could mask a bug elsewhere in
KVM.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-11-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Short circuit vmx_check_nested_events() if an unblocked IRQ/NMI/SMI is
pending and needs to be injected into L2, priority between coincident
events is not dependent on exiting behavior.
Fixes: b518ba9fa691 ("KVM: nSVM: implement check_nested_events for interrupts")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Report interrupts as allowed when the vCPU is in L2 and L2 is being run with
exit-on-interrupts enabled and EFLAGS.IF=1 (either on the host or on the guest
according to VINTR). Interrupts are always unblocked from L1's perspective
in this case.
While moving nested_exit_on_intr to svm.h, use INTERCEPT_INTR properly instead
of assuming it's zero (which it is of course).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Check for an unblocked SMI in vmx_check_nested_events() so that pending
SMIs are correctly prioritized over IRQs and NMIs when the latter events
will trigger VM-Exit. This also fixes an issue where an SMI that was
marked pending while processing a nested VM-Enter wouldn't trigger an
immediate exit, i.e. would be incorrectly delayed until L2 happened to
take a VM-Exit.
Fixes: 64d6067057d96 ("KVM: x86: stubs for SMM support")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-10-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Short circuit vmx_check_nested_events() if an unblocked IRQ/NMI is
pending and needs to be injected into L2, priority between coincident
events is not dependent on exiting behavior.
Fixes: b6b8a1451fc4 ("KVM: nVMX: Rework interception of IRQs and NMIs")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-9-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Move the architectural (non-KVM specific) interrupt/NMI/SMI blocking checks
to a separate helper so that they can be used in a future patch by
svm_check_nested_events().
No functional change intended.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Move the architectural (non-KVM specific) interrupt/NMI blocking checks
to a separate helper so that they can be used in a future patch by
vmx_check_nested_events().
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-8-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Unlike VMX, SVM allows a hypervisor to take a SMI vmexit without having
any special SMM-monitor enablement sequence. Therefore, it has to be
handled like interrupts and NMIs. Check for an unblocked SMI in
svm_check_nested_events() so that pending SMIs are correctly prioritized
over IRQs and NMIs when the latter events will trigger VM-Exit.
Note that there is no need to test explicitly for SMI vmexits, because
guests always runs outside SMM and therefore can never get an SMI while
they are blocked.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Report NMIs as allowed when the vCPU is in L2 and L2 is being run with
Exit-on-NMI enabled, as NMIs are always unblocked from L1's perspective
in this case.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Report NMIs as allowed when the vCPU is in L2 and L2 is being run with
Exit-on-NMI enabled, as NMIs are always unblocked from L1's perspective
in this case.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-7-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Do not hardcode is_smm so that all the architectural conditions for
blocking SMIs are listed in a single place. Well, in two places because
this introduces some code duplication between Intel and AMD.
This ensures that nested SVM obeys GIF in kvm_vcpu_has_events.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Return an actual bool for kvm_x86_ops' {interrupt_nmi}_allowed() hook to
better reflect the return semantics, and to avoid creating an even
bigger mess when the related VMX code is refactored in upcoming patches.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-5-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Re-request KVM_REQ_EVENT if vcpu_enter_guest() bails after processing
pending requests and an immediate exit was requested. This fixes a bug
where a pending event, e.g. VMX preemption timer, is delayed and/or lost
if the exit was deferred due to something other than a higher priority
_injected_ event, e.g. due to a pending nested VM-Enter. This bug only
affects the !injected case as kvm_x86_ops.cancel_injection() sets
KVM_REQ_EVENT to redo the injection, but that's purely serendipitous
behavior with respect to the deferred event.
Note, emulated preemption timer isn't the only event that can be
affected, it simply happens to be the only event where not re-requesting
KVM_REQ_EVENT is blatantly visible to the guest.
Fixes: f4124500c2c13 ("KVM: nVMX: Fully emulate preemption timer")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a kvm_x86_ops hook to detect a nested pending "hypervisor timer" and
use it to effectively open a window for servicing the expired timer.
Like pending SMIs on VMX, opening a window simply means requesting an
immediate exit.
This fixes a bug where an expired VMX preemption timer (for L2) will be
delayed and/or lost if a pending exception is injected into L2. The
pending exception is rightly prioritized by vmx_check_nested_events()
and injected into L2, with the preemption timer left pending. Because
no window opened, L2 is free to run uninterrupted.
Fixes: f4124500c2c13 ("KVM: nVMX: Fully emulate preemption timer")
Reported-by: Jim Mattson <jmattson@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Peter Shier <pshier@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-3-sean.j.christopherson@intel.com>
[Check it in kvm_vcpu_has_events too, to ensure that the preemption
timer is serviced promptly even if the vCPU is halted and L1 is not
intercepting HLT. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Short circuit vmx_check_nested_events() if an exception is pending and
needs to be injected into L2, priority between coincident events is not
dependent on exiting behavior. This fixes a bug where a single-step #DB
that is not intercepted by L1 is incorrectly dropped due to servicing a
VMX Preemption Timer VM-Exit.
Injected exceptions also need to be blocked if nested VM-Enter is
pending or an exception was already injected, otherwise injecting the
exception could overwrite an existing event injection from L1.
Technically, this scenario should be impossible, i.e. KVM shouldn't
inject its own exception during nested VM-Enter. This will be addressed
in a future patch.
Note, event priority between SMI, NMI and INTR is incorrect for L2, e.g.
SMI should take priority over VM-Exit on NMI/INTR, and NMI that is
injected into L2 should take priority over VM-Exit INTR. This will also
be addressed in a future patch.
Fixes: b6b8a1451fc4 ("KVM: nVMX: Rework interception of IRQs and NMIs")
Reported-by: Jim Mattson <jmattson@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Peter Shier <pshier@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Migrate nested guest NMI intercept processing
to new check_nested_events.
Signed-off-by: Cathy Avery <cavery@redhat.com>
Message-Id: <20200414201107.22952-2-cavery@redhat.com>
[Reorder clauses as NMIs have higher priority than IRQs; inject
immediate vmexit as is now done for IRQ vmexits. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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We can immediately leave SVM guest mode in svm_check_nested_events
now that we have the nested_run_pending mechanism. This makes
things easier because we can run the rest of inject_pending_event
with GIF=0, and KVM will naturally end up requesting the next
interrupt window.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Similar to VMX, we need to leave the halted state when performing a vmexit.
Failure to do so will cause a hang after vmexit.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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We want to inject vmexits immediately from svm_check_nested_events,
so that the interrupt/NMI window requests happen in inject_pending_event
right after it returns.
This however has the same issue as in vmx_check_nested_events, so
introduce a nested_run_pending flag with the exact same purpose
of delaying vmexit injection after the vmentry.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Though rdpkru and wrpkru are contingent upon CR4.PKE, the PKRU
resource isn't. It can be read with XSAVE and written with XRSTOR.
So, if we don't set the guest PKRU value here(kvm_load_guest_xsave_state),
the guest can read the host value.
In case of kvm_load_host_xsave_state, guest with CR4.PKE clear could
potentially use XRSTOR to change the host PKRU value.
While at it, move pkru state save/restore to common code and the
host_pkru field to kvm_vcpu_arch. This will let SVM support protection keys.
Cc: stable@vger.kernel.org
Reported-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Message-Id: <158932794619.44260.14508381096663848853.stgit@naples-babu.amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Merge misc fixes from Andrew Morton:
"14 fixes and one selftest to verify the ipc fixes herein"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: limit boost_watermark on small zones
ubsan: disable UBSAN_ALIGNMENT under COMPILE_TEST
mm/vmscan: remove unnecessary argument description of isolate_lru_pages()
epoll: atomically remove wait entry on wake up
kselftests: introduce new epoll60 testcase for catching lost wakeups
percpu: make pcpu_alloc() aware of current gfp context
mm/slub: fix incorrect interpretation of s->offset
scripts/gdb: repair rb_first() and rb_last()
eventpoll: fix missing wakeup for ovflist in ep_poll_callback
arch/x86/kvm/svm/sev.c: change flag passed to GUP fast in sev_pin_memory()
scripts/decodecode: fix trapping instruction formatting
kernel/kcov.c: fix typos in kcov_remote_start documentation
mm/page_alloc: fix watchdog soft lockups during set_zone_contiguous()
mm, memcg: fix error return value of mem_cgroup_css_alloc()
ipc/mqueue.c: change __do_notify() to bypass check_kill_permission()
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The commit 64b5bd270426 ("KVM: nSVM: ignore L1 interrupt window
while running L2 with V_INTR_MASKING=1") introduced a WARN_ON,
which checks if AVIC is enabled when trying to set V_IRQ
in the VMCB for enabling irq window.
The following warning is triggered because the requesting vcpu
(to deactivate AVIC) does not get to process APICv update request
for itself until the next #vmexit.
WARNING: CPU: 0 PID: 118232 at arch/x86/kvm/svm/svm.c:1372 enable_irq_window+0x6a/0xa0 [kvm_amd]
RIP: 0010:enable_irq_window+0x6a/0xa0 [kvm_amd]
Call Trace:
kvm_arch_vcpu_ioctl_run+0x6e3/0x1b50 [kvm]
? kvm_vm_ioctl_irq_line+0x27/0x40 [kvm]
? _copy_to_user+0x26/0x30
? kvm_vm_ioctl+0xb3e/0xd90 [kvm]
? set_next_entity+0x78/0xc0
kvm_vcpu_ioctl+0x236/0x610 [kvm]
ksys_ioctl+0x8a/0xc0
__x64_sys_ioctl+0x1a/0x20
do_syscall_64+0x58/0x210
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes by sending APICV update request to all other vcpus, and
immediately update APIC for itself.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lkml.org/lkml/2020/5/2/167
Fixes: 64b5bd270426 ("KVM: nSVM: ignore L1 interrupt window while running L2 with V_INTR_MASKING=1")
Message-Id: <1588818939-54264-1-git-send-email-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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This allows making request to all other vcpus except the one
specified in the parameter.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <1588771076-73790-2-git-send-email-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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When KVM_EXIT_DEBUG is raised for the disabled-breakpoints case (DR7.GD),
DR6 was incorrectly copied from the value in the VM. Instead,
DR6.BD should be set in order to catch this case.
On AMD this does not need any special code because the processor triggers
a #DB exception that is intercepted. However, the testcase would fail
without the previous patch because both DR6.BS and DR6.BD would be set.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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There are two issues with KVM_EXIT_DEBUG on AMD, whose root cause is the
different handling of DR6 on intercepted #DB exceptions on Intel and AMD.
On Intel, #DB exceptions transmit the DR6 value via the exit qualification
field of the VMCS, and the exit qualification only contains the description
of the precise event that caused a vmexit.
On AMD, instead the DR6 field of the VMCB is filled in as if the #DB exception
was to be injected into the guest. This has two effects when guest debugging
is in use:
* the guest DR6 is clobbered
* the kvm_run->debug.arch.dr6 field can accumulate more debug events, rather
than just the last one that happened (the testcase in the next patch covers
this issue).
This patch fixes both issues by emulating, so to speak, the Intel behavior
on AMD processors. The important observation is that (after the previous
patches) the VMCB value of DR6 is only ever observable from the guest is
KVM_DEBUGREG_WONT_EXIT is set. Therefore we can actually set vmcb->save.dr6
to any value we want as long as KVM_DEBUGREG_WONT_EXIT is clear, which it
will be if guest debugging is enabled.
Therefore it is possible to enter the guest with an all-zero DR6,
reconstruct the #DB payload from the DR6 we get at exit time, and let
kvm_deliver_exception_payload move the newly set bits into vcpu->arch.dr6.
Some extra bits may be included in the payload if KVM_DEBUGREG_WONT_EXIT
is set, but this is harmless.
This may not be the most optimized way to deal with this, but it is
simple and, being confined within SVM code, it gets rid of the set_dr6
callback and kvm_update_dr6.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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kvm_x86_ops.set_dr6 is only ever called with vcpu->arch.dr6 as the
second argument. Ensure that the VMCB value is synchronized to
vcpu->arch.dr6 on #DB (both "normal" and nested) and nested vmentry, so
that the current value of DR6 is always available in vcpu->arch.dr6.
The get_dr6 callback can just access vcpu->arch.dr6 and becomes redundant.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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When trying to lock read-only pages, sev_pin_memory() fails because
FOLL_WRITE is used as the flag for get_user_pages_fast().
Commit 73b0140bf0fe ("mm/gup: change GUP fast to use flags rather than a
write 'bool'") updated the get_user_pages_fast() call sites to use
flags, but incorrectly updated the call in sev_pin_memory(). As the
original coding of this call was correct, revert the change made by that
commit.
Fixes: 73b0140bf0fe ("mm/gup: change GUP fast to use flags rather than a write 'bool'")
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Mike Marshall <hubcap@omnibond.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Link: http://lkml.kernel.org/r/20200423152419.87202-1-Janakarajan.Natarajan@amd.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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When single-step triggered with KVM_SET_GUEST_DEBUG, we should fill in the pc
value with current linear RIP rather than the cached singlestep address.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20200505205000.188252-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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RTM should always been set even with KVM_EXIT_DEBUG on #DB.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20200505205000.188252-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Go through kvm_queue_exception_p so that the payload is correctly delivered
through the exit qualification, and add a kvm_update_dr6 call to
kvm_deliver_exception_payload that is needed on AMD.
Reported-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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KVM_CAP_SET_GUEST_DEBUG should be supported for x86 however it's not declared
as supported. My wild guess is that userspaces like QEMU are using "#ifdef
KVM_CAP_SET_GUEST_DEBUG" to check for the capability instead, but that could be
wrong because the compilation host may not be the runtime host.
The userspace might still want to keep the old "#ifdef" though to not break the
guest debug on old kernels.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20200505154750.126300-1-peterx@redhat.com>
[Do the same for PPC and s390. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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KVM_CAP_SET_GUEST_DEBUG should be supported for x86 however it's not declared
as supported. My wild guess is that userspaces like QEMU are using "#ifdef
KVM_CAP_SET_GUEST_DEBUG" to check for the capability instead, but that could be
wrong because the compilation host may not be the runtime host.
The userspace might still want to keep the old "#ifdef" though to not break the
guest debug on old kernels.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20200505154750.126300-1-peterx@redhat.com>
[Do the same for PPC and s390. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Using CPUID data can be useful for the processor compatibility
check, but that's it. Using it to compute guest-reserved bits
can have both false positives (such as LA57 and UMIP which we
are already handling) and false negatives: in particular, with
this patch we don't allow anymore a KVM guest to set CR4.PKE
when CR4.PKE is clear on the host.
Fixes: b9dd21e104bc ("KVM: x86: simplify handling of PKRU")
Reported-by: Jim Mattson <jmattson@google.com>
Tested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Clear CF and ZF in the VM-Exit path after doing __FILL_RETURN_BUFFER so
that KVM doesn't interpret clobbered RFLAGS as a VM-Fail. Filling the
RSB has always clobbered RFLAGS, its current incarnation just happens
clear CF and ZF in the processs. Relying on the macro to clear CF and
ZF is extremely fragile, e.g. commit 089dd8e53126e ("x86/speculation:
Change FILL_RETURN_BUFFER to work with objtool") tweaks the loop such
that the ZF flag is always set.
Reported-by: Qian Cai <cai@lca.pw>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Fixes: f2fde6a5bcfcf ("KVM: VMX: Move RSB stuffing to before the first RET after VM-Exit")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200506035355.2242-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Commit f458d039db7e ("kvm: ioapic: Lazy update IOAPIC EOI") introduces
the following infinite loop:
BUG: stack guard page was hit at 000000008f595917 \
(stack is 00000000bdefe5a4..00000000ae2b06f5)
kernel stack overflow (double-fault): 0000 [#1] SMP NOPTI
RIP: 0010:kvm_set_irq+0x51/0x160 [kvm]
Call Trace:
irqfd_resampler_ack+0x32/0x90 [kvm]
kvm_notify_acked_irq+0x62/0xd0 [kvm]
kvm_ioapic_update_eoi_one.isra.0+0x30/0x120 [kvm]
ioapic_set_irq+0x20e/0x240 [kvm]
kvm_ioapic_set_irq+0x5c/0x80 [kvm]
kvm_set_irq+0xbb/0x160 [kvm]
? kvm_hv_set_sint+0x20/0x20 [kvm]
irqfd_resampler_ack+0x32/0x90 [kvm]
kvm_notify_acked_irq+0x62/0xd0 [kvm]
kvm_ioapic_update_eoi_one.isra.0+0x30/0x120 [kvm]
ioapic_set_irq+0x20e/0x240 [kvm]
kvm_ioapic_set_irq+0x5c/0x80 [kvm]
kvm_set_irq+0xbb/0x160 [kvm]
? kvm_hv_set_sint+0x20/0x20 [kvm]
....
The re-entrancy happens because the irq state is the OR of
the interrupt state and the resamplefd state. That is, we don't
want to show the state as 0 until we've had a chance to set the
resamplefd. But if the interrupt has _not_ gone low then
ioapic_set_irq is invoked again, causing an infinite loop.
This can only happen for a level-triggered interrupt, otherwise
irqfd_inject would immediately set the KVM_USERSPACE_IRQ_SOURCE_ID high
and then low. Fortunately, in the case of level-triggered interrupts the VMEXIT already happens because
TMR is set. Thus, fix the bug by restricting the lazy invocation
of the ack notifier to edge-triggered interrupts, the only ones that
need it.
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reported-by: borisvk@bstnet.org
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://www.spinics.net/lists/kvm/msg213512.html
Fixes: f458d039db7e ("kvm: ioapic: Lazy update IOAPIC EOI")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207489
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The corresponding code was added for VMX in commit 42dbaa5a057
("KVM: x86: Virtualize debug registers, 2008-12-15) but never for AMD.
Fix this.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Use BUG() in the impossible-to-hit default case when switching on the
scope of INVEPT to squash a warning with clang 11 due to clang treating
the BUG_ON() as conditional.
>> arch/x86/kvm/vmx/nested.c:5246:3: warning: variable 'roots_to_free'
is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
BUG_ON(1);
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: ce8fe7b77bd8 ("KVM: nVMX: Free only the affected contexts when emulating INVEPT")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200504153506.28898-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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VMRUN is not supported inside the SMM handler and the behavior is undefined.
Just raise a #UD.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Use an unsigned long for 'exit_qual' in nested_vmx_reflect_vmexit(), the
EXIT_QUALIFICATION field is naturally sized, not a 32-bit field.
The bug is most easily observed by doing VMXON (or any VMX instruction)
in L2 with a negative displacement, in which case dropping the upper
bits on nested VM-Exit results in L1 calculating the wrong virtual
address for the memory operand, e.g. "vmxon -0x8(%rbp)" yields:
Unhandled cpu exception 14 #PF at ip 0000000000400553
rbp=0000000000537000 cr2=0000000100536ff8
Fixes: fbdd50250396d ("KVM: nVMX: Move VM-Fail check out of nested_vmx_exit_reflected()")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423001127.13490-1-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Drop nested_vmx_l1_wants_exit()'s initialization of intr_info from
vmx_get_intr_info() that was inadvertantly introduced along with the
caching mechanism. EXIT_REASON_EXCEPTION_NMI, the only consumer of
intr_info, populates the variable before using it.
Fixes: bb53120d67cd ("KVM: VMX: Cache vmcs.EXIT_INTR_INFO using arch avail_reg flags")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200421075328.14458-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Clean up some of the patching of kvm_x86_ops, by moving kvm_x86_ops related to
nested virtualization into a separate struct.
As a result, these ops will always be non-NULL on VMX. This is not a problem:
* check_nested_events is only called if is_guest_mode(vcpu) returns true
* get_nested_state treats VMXOFF state the same as nested being disabled
* set_nested_state fails if you attempt to set nested state while
nesting is disabled
* nested_enable_evmcs could already be called on a CPU without VMX enabled
in CPUID.
* nested_get_evmcs_version was fixed in the previous patch
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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In the next patch nested_get_evmcs_version will be always set in kvm_x86_ops for
VMX, even if nesting is disabled. Therefore, check whether VMX (aka nesting)
is available in the function, the caller will not do the check anymore.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Both Intel and AMD now implement it, so there is no need to check if the
callback is implemented.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master
KVM: s390: Fix for 5.7 and maintainer update
- Silence false positive lockdep warning
- add Claudio as reviewer
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When a nested page fault is taken from an address that does not have
a memslot associated to it, kvm_mmu_do_page_fault returns RET_PF_EMULATE
(via mmu_set_spte) and kvm_mmu_page_fault then invokes svm_need_emulation_on_page_fault.
The default answer there is to return false, but in this case this just
causes the page fault to be retried ad libitum. Since this is not a
fast path, and the only other case where it is taken is an erratum,
just stick a kvm_vcpu_gfn_to_memslot check in there to detect the
common case where the erratum is not happening.
This fixes an infinite loop in the new set_memory_region_test.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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In earlier versions of kvm, 'kvm_run' was an independent structure
and was not included in the vcpu structure. At present, 'kvm_run'
is already included in the vcpu structure, so the parameter
'kvm_run' is redundant.
This patch simplifies the function definition, removes the extra
'kvm_run' parameter, and extracts it from the 'kvm_vcpu' structure
if necessary.
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Message-Id: <20200416051057.26526-1-tianjia.zhang@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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