Sean Christopherson f5d16bb9be KVM: x86/mmu: Don't attempt to map leaf if target TDP MMU SPTE is frozen
Hoist the is_removed_spte() check above the "level == goal_level" check
when walking SPTEs during a TDP MMU page fault to avoid attempting to map
a leaf entry if said entry is frozen by a different task/vCPU.

  ------------[ cut here ]------------
  WARNING: CPU: 3 PID: 939 at arch/x86/kvm/mmu/tdp_mmu.c:653 kvm_tdp_mmu_map+0x269/0x4b0
  Modules linked in: kvm_intel
  CPU: 3 PID: 939 Comm: nx_huge_pages_t Not tainted 6.1.0-rc4+ #67
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:kvm_tdp_mmu_map+0x269/0x4b0
  RSP: 0018:ffffc9000068fba8 EFLAGS: 00010246
  RAX: 00000000000005a0 RBX: ffffc9000068fcc0 RCX: 0000000000000005
  RDX: ffff88810741f000 RSI: ffff888107f04600 RDI: ffffc900006a3000
  RBP: 060000010b000bf3 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 000ffffffffff000 R12: 0000000000000005
  R13: ffff888113670000 R14: ffff888107464958 R15: 0000000000000000
  FS:  00007f01c942c740(0000) GS:ffff888277cc0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000000117013006 CR4: 0000000000172ea0
  Call Trace:
   <TASK>
   kvm_tdp_page_fault+0x10c/0x130
   kvm_mmu_page_fault+0x103/0x680
   vmx_handle_exit+0x132/0x5a0 [kvm_intel]
   vcpu_enter_guest+0x60c/0x16f0
   kvm_arch_vcpu_ioctl_run+0x1e2/0x9d0
   kvm_vcpu_ioctl+0x271/0x660
   __x64_sys_ioctl+0x80/0xb0
   do_syscall_64+0x2b/0x50
   entry_SYSCALL_64_after_hwframe+0x46/0xb0
   </TASK>
  ---[ end trace 0000000000000000 ]---

Fixes: 63d28a25e0 ("KVM: x86/mmu: simplify kvm_tdp_mmu_map flow when guest has to retry")
Cc: Robert Hoo <robert.hu@linux.intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Robert Hoo <robert.hu@linux.intel.com>
Message-Id: <20221213033030.83345-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-23 12:33:52 -05:00
2022-09-28 09:02:20 +02:00
2022-09-28 09:02:20 +02:00
2022-10-20 21:27:21 -07:00
2022-09-28 09:02:20 +02:00
2022-11-06 15:07:11 -08:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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