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  1. 08 12月, 2021 20 次提交
  3. 02 12月, 2021 1 次提交
  5. 30 11月, 2021 1 次提交
    • P
      KVM: x86: check PIR even for vCPUs with disabled APICv · 37c4dbf3
      由 Paolo Bonzini 提交于 
      The IRTE for an assigned device can trigger a POSTED_INTR_VECTOR even
if APICv is disabled on the vCPU that receives it.  In that case, the
interrupt will just cause a vmexit and leave the ON bit set together
with the PIR bit corresponding to the interrupt.

Right now, the interrupt would not be delivered until APICv is re-enabled.
However, fixing this is just a matter of always doing the PIR->IRR
synchronization, even if the vCPU has temporarily disabled APICv.

This is not a problem for performance, or if anything it is an
improvement.  First, in the common case where vcpu->arch.apicv_active is
true, one fewer check has to be performed.  Second, static_call_cond will
elide the function call if APICv is not present or disabled.  Finally,
in the case for AMD hardware we can remove the sync_pir_to_irr callback:
it is only needed for apic_has_interrupt_for_ppr, and that function
already has a fallback for !APICv.

Cc: stable@vger.kernel.org
Co-developed-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NSean Christopherson <seanjc@google.com>
Reviewed-by: NMaxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: NDavid Matlack <dmatlack@google.com>
Message-Id: <20211123004311.2954158-4-pbonzini@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      37c4dbf3
  7. 26 11月, 2021 4 次提交
  9. 18 11月, 2021 3 次提交
    • V
      KVM: x86: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS · 2845e735
      由 Vitaly Kuznetsov 提交于 
      It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211116163443.88707-7-vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      2845e735
    • T
      KVM: x86: Assume a 64-bit hypercall for guests with protected state · b5aead00
      由 Tom Lendacky 提交于 
      When processing a hypercall for a guest with protected state, currently
SEV-ES guests, the guest CS segment register can't be checked to
determine if the guest is in 64-bit mode. For an SEV-ES guest, it is
expected that communication between the guest and the hypervisor is
performed to shared memory using the GHCB. In order to use the GHCB, the
guest must have been in long mode, otherwise writes by the guest to the
GHCB would be encrypted and not be able to be comprehended by the
hypervisor.

Create a new helper function, is_64_bit_hypercall(), that assumes the
guest is in 64-bit mode when the guest has protected state, and returns
true, otherwise invoking is_64_bit_mode() to determine the mode. Update
the hypercall related routines to use is_64_bit_hypercall() instead of
is_64_bit_mode().

Add a WARN_ON_ONCE() to is_64_bit_mode() to catch occurences of calls to
this helper function for a guest running with protected state.

Fixes: f1c6366e ("KVM: SVM: Add required changes to support intercepts under SEV-ES")
Reported-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
Message-Id: <e0b20c770c9d0d1403f23d83e785385104211f74.1621878537.git.thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      b5aead00
    • D
      KVM: Fix steal time asm constraints · 964b7aa0
      由 David Woodhouse 提交于 
      In 64-bit mode, x86 instruction encoding allows us to use the low 8 bits
of any GPR as an 8-bit operand. In 32-bit mode, however, we can only use
the [abcd] registers. For which, GCC has the "q" constraint instead of
the less restrictive "r".

Also fix st->preempted, which is an input/output operand rather than an
input.

Fixes: 7e2175eb ("KVM: x86: Fix recording of guest steal time / preempted status")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Message-Id: <89bf72db1b859990355f9c40713a34e0d2d86c98.camel@infradead.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      964b7aa0
  11. 16 11月, 2021 1 次提交
    • 黄
      KVM: x86: Fix uninitialized eoi_exit_bitmap usage in vcpu_load_eoi_exitmap() · c5adbb3a
      由 黄乐 提交于 
      In vcpu_load_eoi_exitmap(), currently the eoi_exit_bitmap[4] array is
initialized only when Hyper-V context is available, in other path it is
just passed to kvm_x86_ops.load_eoi_exitmap() directly from on the stack,
which would cause unexpected interrupt delivery/handling issues, e.g. an
*old* linux kernel that relies on PIT to do clock calibration on KVM might
randomly fail to boot.

Fix it by passing ioapic_handled_vectors to load_eoi_exitmap() when Hyper-V
context is not available.

Fixes: f2bc14b6 ("KVM: x86: hyper-v: Prepare to meet unallocated Hyper-V context")
Cc: stable@vger.kernel.org
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NHuang Le <huangle1@jd.com>
Message-Id: <62115b277dab49ea97da5633f8522daf@jd.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      c5adbb3a
  13. 12 11月, 2021 1 次提交
  15. 11 11月, 2021 8 次提交
    • V
      KVM: x86: Drop arbitrary KVM_SOFT_MAX_VCPUS · da1bfd52
      由 Vitaly Kuznetsov 提交于 
      KVM_CAP_NR_VCPUS is used to get the "recommended" maximum number of
VCPUs and arm64/mips/riscv report num_online_cpus(). Powerpc reports
either num_online_cpus() or num_present_cpus(), s390 has multiple
constants depending on hardware features. On x86, KVM reports an
arbitrary value of '710' which is supposed to be the maximum tested
value but it's possible to test all KVM_MAX_VCPUS even when there are
less physical CPUs available.

Drop the arbitrary '710' value and return num_online_cpus() on x86 as
well. The recommendation will match other architectures and will mean
'no CPU overcommit'.

For reference, QEMU only queries KVM_CAP_NR_VCPUS to print a warning
when the requested vCPU number exceeds it. The static limit of '710'
is quite weird as smaller systems with just a few physical CPUs should
certainly "recommend" less.
Suggested-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211111134733.86601-1-vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      da1bfd52
    • V
      KVM: Move INVPCID type check from vmx and svm to the common kvm_handle_invpcid() · 796c83c5
      由 Vipin Sharma 提交于 
      Handle #GP on INVPCID due to an invalid type in the common switch
statement instead of relying on the callers (VMX and SVM) to manually
validate the type.

Unlike INVVPID and INVEPT, INVPCID is not explicitly documented to check
the type before reading the operand from memory, so deferring the
type validity check until after that point is architecturally allowed.
Signed-off-by: NVipin Sharma <vipinsh@google.com>
Reviewed-by: NSean Christopherson <seanjc@google.com>
Message-Id: <20211109174426.2350547-3-vipinsh@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      796c83c5
    • V
      KVM: x86: Rename kvm_lapic_enable_pv_eoi() · 77c3323f
      由 Vitaly Kuznetsov 提交于 
      kvm_lapic_enable_pv_eoi() is a misnomer as the function is also
used to disable PV EOI. Rename it to kvm_lapic_set_pv_eoi().

No functional change intended.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211108152819.12485-2-vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      77c3323f
    • M
      KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active · cae72dcc
      由 Maxim Levitsky 提交于 
      KVM_GUESTDBG_BLOCKIRQ relies on interrupts being injected using
standard kvm's inject_pending_event, and not via APICv/AVIC.

Since this is a debug feature, just inhibit APICv/AVIC while
KVM_GUESTDBG_BLOCKIRQ is in use on at least one vCPU.

Fixes: 61e5f69e ("KVM: x86: implement KVM_GUESTDBG_BLOCKIRQ")
Reported-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NMaxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: NSean Christopherson <seanjc@google.com>
Tested-by: NSean Christopherson <seanjc@google.com>
Message-Id: <20211108090245.166408-1-mlevitsk@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      cae72dcc
    • J
      kvm: x86: Convert return type of *is_valid_rdpmc_ecx() to bool · e6cd31f1
      由 Jim Mattson 提交于 
      These function names sound like predicates, and they have siblings,
*is_valid_msr(), which _are_ predicates. Moreover, there are comments
that essentially warn that these functions behave unexpectedly.

Flip the polarity of the return values, so that they become
predicates, and convert the boolean result to a success/failure code
at the outer call site.
Suggested-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NJim Mattson <jmattson@google.com>
Reviewed-by: NSean Christopherson <seanjc@google.com>
Message-Id: <20211105202058.1048757-1-jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      e6cd31f1
    • D
      KVM: x86: Fix recording of guest steal time / preempted status · 7e2175eb
      由 David Woodhouse 提交于 
      In commit b0431382 ("x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is
not missed") we switched to using a gfn_to_pfn_cache for accessing the
guest steal time structure in order to allow for an atomic xchg of the
preempted field. This has a couple of problems.

Firstly, kvm_map_gfn() doesn't work at all for IOMEM pages when the
atomic flag is set, which it is in kvm_steal_time_set_preempted(). So a
guest vCPU using an IOMEM page for its steal time would never have its
preempted field set.

Secondly, the gfn_to_pfn_cache is not invalidated in all cases where it
should have been. There are two stages to the GFN->PFN conversion;
first the GFN is converted to a userspace HVA, and then that HVA is
looked up in the process page tables to find the underlying host PFN.
Correct invalidation of the latter would require being hooked up to the
MMU notifiers, but that doesn't happen---so it just keeps mapping and
unmapping the *wrong* PFN after the userspace page tables change.

In the !IOMEM case at least the stale page *is* pinned all the time it's
cached, so it won't be freed and reused by anyone else while still
receiving the steal time updates. The map/unmap dance only takes care
of the KVM administrivia such as marking the page dirty.

Until the gfn_to_pfn cache handles the remapping automatically by
integrating with the MMU notifiers, we might as well not get a
kernel mapping of it, and use the perfectly serviceable userspace HVA
that we already have.  We just need to implement the atomic xchg on
the userspace address with appropriate exception handling, which is
fairly trivial.

Cc: stable@vger.kernel.org
Fixes: b0431382 ("x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is not missed")
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Message-Id: <3645b9b889dac6438394194bb5586a46b68d581f.camel@infradead.org>
[I didn't entirely agree with David's assessment of the
 usefulness of the gfn_to_pfn cache, and integrated the outcome
 of the discussion in the above commit message. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      7e2175eb
    • P
      KVM: SEV: Add support for SEV intra host migration · b5663931
      由 Peter Gonda 提交于 
      For SEV to work with intra host migration, contents of the SEV info struct
such as the ASID (used to index the encryption key in the AMD SP) and
the list of memory regions need to be transferred to the target VM.
This change adds a commands for a target VMM to get a source SEV VM's sev
info.
Signed-off-by: NPeter Gonda <pgonda@google.com>
Suggested-by: NSean Christopherson <seanjc@google.com>
Reviewed-by: NMarc Orr <marcorr@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.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: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-3-pgonda@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      b5663931
    • P
      KVM: generalize "bugged" VM to "dead" VM · f4d31653
      由 Paolo Bonzini 提交于 
      Generalize KVM_REQ_VM_BUGGED so that it can be called even in cases
where it is by design that the VM cannot be operated upon.  In this
case any KVM_BUG_ON should still warn, so introduce a new flag
kvm->vm_dead that is separate from kvm->vm_bugged.
Suggested-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      f4d31653
  17. 28 10月, 2021 1 次提交
    • D
      KVM: x86: Take srcu lock in post_kvm_run_save() · f3d1436d
      由 David Woodhouse 提交于 
      The Xen interrupt injection for event channels relies on accessing the
guest's vcpu_info structure in __kvm_xen_has_interrupt(), through a
gfn_to_hva_cache.

This requires the srcu lock to be held, which is mostly the case except
for this code path:

[   11.822877] WARNING: suspicious RCU usage
[   11.822965] -----------------------------
[   11.823013] include/linux/kvm_host.h:664 suspicious rcu_dereference_check() usage!
[   11.823131]
[   11.823131] other info that might help us debug this:
[   11.823131]
[   11.823196]
[   11.823196] rcu_scheduler_active = 2, debug_locks = 1
[   11.823253] 1 lock held by dom:0/90:
[   11.823292]  #0: ffff998956ec8118 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0x85/0x680
[   11.823379]
[   11.823379] stack backtrace:
[   11.823428] CPU: 2 PID: 90 Comm: dom:0 Kdump: loaded Not tainted 5.4.34+ #5
[   11.823496] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[   11.823612] Call Trace:
[   11.823645]  dump_stack+0x7a/0xa5
[   11.823681]  lockdep_rcu_suspicious+0xc5/0x100
[   11.823726]  __kvm_xen_has_interrupt+0x179/0x190
[   11.823773]  kvm_cpu_has_extint+0x6d/0x90
[   11.823813]  kvm_cpu_accept_dm_intr+0xd/0x40
[   11.823853]  kvm_vcpu_ready_for_interrupt_injection+0x20/0x30
              < post_kvm_run_save() inlined here >
[   11.823906]  kvm_arch_vcpu_ioctl_run+0x135/0x6a0
[   11.823947]  kvm_vcpu_ioctl+0x263/0x680

Fixes: 40da8ccd ("KVM: x86/xen: Add event channel interrupt vector upcall")
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Message-Id: <606aaaf29fca3850a63aa4499826104e77a72346.camel@infradead.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      f3d1436d