linux.git/arch/x86/kernel/kvm.c, branch v5.9

Revert "KVM: Check the allocation of pv cpu mask"

2020-09-20T21:29:58+00:00

The commit 0f990222108d ("KVM: Check the allocation of pv cpu mask") we
have in 5.9-rc5 has two issue:
1) Compilation fails for !CONFIG_SMP, see:
   https://bugzilla.kernel.org/show_bug.cgi?id=209285

2) This commit completely disables PV TLB flush, see
   https://lore.kernel.org/kvm/87y2lrnnyf.fsf@vitty.brq.redhat.com/

The allocation problem is likely a theoretical one, if we don't
have memory that early in boot process we're likely doomed anyway.
Let's solve it properly later.

This reverts commit 0f990222108d214a0924d920e6095b58107d7b59.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Paolo Bonzini

x86/kvm: don't forget to ACK async PF IRQ

2020-09-12T06:22:21+00:00

Merge commit 26d05b368a5c0 ("Merge branch 'kvm-async-pf-int' into HEAD")
tried to adapt the new interrupt based async PF mechanism to the newly
introduced IDTENTRY magic but unfortunately it missed the fact that
DEFINE_IDTENTRY_SYSVEC() doesn't call ack_APIC_irq() on its own and
all DEFINE_IDTENTRY_SYSVEC() users have to call it manually.

As the result all multi-CPU KVM guest hang on boot when
KVM_FEATURE_ASYNC_PF_INT is present. The breakage went unnoticed because no
KVM userspace (e.g. QEMU) currently set it (and thus async PF mechanism
is currently disabled) but we're about to change that.

Fixes: 26d05b368a5c0 ("Merge branch 'kvm-async-pf-int' into HEAD")
Signed-off-by: Vitaly Kuznetsov 
Message-Id: <20200908135350.355053-3-vkuznets@redhat.com>
Tested-by: Ingo Molnar 
Signed-off-by: Paolo Bonzini

x86/kvm: properly use DEFINE_IDTENTRY_SYSVEC() macro

2020-09-12T06:22:07+00:00

DEFINE_IDTENTRY_SYSVEC() already contains irqentry_enter()/
irqentry_exit().

Signed-off-by: Vitaly Kuznetsov 
Message-Id: <20200908135350.355053-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini

KVM: Check the allocation of pv cpu mask

2020-09-11T17:15:10+00:00

check the allocation of per-cpu __pv_cpu_mask. Initialize ops only when
successful.

Signed-off-by: Haiwei Li 
Message-Id: 
Signed-off-by: Paolo Bonzini

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2020-08-06T19:59:31+00:00

Pull KVM updates from Paolo Bonzini:
 "s390:
   - implement diag318

  x86:
   - Report last CPU for debugging
   - Emulate smaller MAXPHYADDR in the guest than in the host
   - .noinstr and tracing fixes from Thomas
   - nested SVM page table switching optimization and fixes

  Generic:
   - Unify shadow MMU cache data structures across architectures"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
  KVM: SVM: Fix sev_pin_memory() error handling
  KVM: LAPIC: Set the TDCR settable bits
  KVM: x86: Specify max TDP level via kvm_configure_mmu()
  KVM: x86/mmu: Rename max_page_level to max_huge_page_level
  KVM: x86: Dynamically calculate TDP level from max level and MAXPHYADDR
  KVM: VXM: Remove temporary WARN on expected vs. actual EPTP level mismatch
  KVM: x86: Pull the PGD's level from the MMU instead of recalculating it
  KVM: VMX: Make vmx_load_mmu_pgd() static
  KVM: x86/mmu: Add separate helper for shadow NPT root page role calc
  KVM: VMX: Drop a duplicate declaration of construct_eptp()
  KVM: nSVM: Correctly set the shadow NPT root level in its MMU role
  KVM: Using macros instead of magic values
  MIPS: KVM: Fix build error caused by 'kvm_run' cleanup
  KVM: nSVM: remove nonsensical EXITINFO1 adjustment on nested NPF
  KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support
  KVM: VMX: optimize #PF injection when MAXPHYADDR does not match
  KVM: VMX: Add guest physical address check in EPT violation and misconfig
  KVM: VMX: introduce vmx_need_pf_intercept
  KVM: x86: update exception bitmap on CPUID changes
  KVM: x86: rename update_bp_intercept to update_exception_bitmap
  ...

x86/entry: Cleanup idtentry_enter/exit

2020-07-24T13:05:01+00:00

Remove the temporary defines and fixup all references.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Kees Cook 
Link: https://lkml.kernel.org/r/20200722220520.855839271@linutronix.de

x86/kvm: Add "nopvspin" parameter to disable PV spinlocks

2020-07-08T20:21:57+00:00

There are cases where a guest tries to switch spinlocks to bare metal
behavior (e.g. by setting "xen_nopvspin" on XEN platform and
"hv_nopvspin" on HYPER_V).

That feature is missed on KVM, add a new parameter "nopvspin" to disable
PV spinlocks for KVM guest.

The new 'nopvspin' parameter will also replace Xen and Hyper-V specific
parameters in future patches.

Define variable nopvsin as global because it will be used in future
patches as above.

Signed-off-by: Zhenzhong Duan 
Reviewed-by: Vitaly Kuznetsov 
Cc: Jonathan Corbet 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Paolo Bonzini 
Cc: Radim Krcmar 
Cc: Sean Christopherson 
Cc: Vitaly Kuznetsov 
Cc: Wanpeng Li 
Cc: Jim Mattson 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Will Deacon 
Signed-off-by: Paolo Bonzini

x86/kvm: Change print code to use pr_*() format

2020-07-08T20:21:56+00:00

pr_*() is preferred than printk(KERN_* ...), after change all the print
in arch/x86/kernel/kvm.c will have "kvm-guest: xxx" style.

No functional change.

Signed-off-by: Zhenzhong Duan 
Reviewed-by: Vitaly Kuznetsov 
Cc: Paolo Bonzini 
Cc: Radim Krcmar 
Cc: Sean Christopherson 
Cc: Vitaly Kuznetsov 
Cc: Wanpeng Li 
Cc: Jim Mattson 
Cc: Joerg Roedel 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Signed-off-by: Paolo Bonzini

Revert "KVM: X86: Fix setup the virt_spin_lock_key before static key get initialized"

2020-07-08T20:21:56+00:00

This reverts commit 34226b6b70980a8f81fff3c09a2c889f77edeeff.

Commit 8990cac6e5ea ("x86/jump_label: Initialize static branching
early") adds jump_label_init() call in setup_arch() to make static
keys initialized early, so we could use the original simpler code
again.

The similar change for XEN is in commit 090d54bcbc54 ("Revert
"x86/paravirt: Set up the virt_spin_lock_key after static keys get
initialized"")

Signed-off-by: Zhenzhong Duan 
Reviewed-by: Vitaly Kuznetsov 
Cc: Paolo Bonzini 
Cc: Radim Krcmar 
Cc: Sean Christopherson 
Cc: Vitaly Kuznetsov 
Cc: Wanpeng Li 
Cc: Jim Mattson 
Cc: Joerg Roedel 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Signed-off-by: Paolo Bonzini

Merge branch 'kvm-async-pf-int' into HEAD

2020-07-08T20:20:30+00:00