https://github.com/torvalds/linux
Revision 2d6144e366fb39609aecf7a658e2e10af37627e9 authored by Wanpeng Li on 25 July 2017, 10:40:46 UTC, committed by Paolo Bonzini on 26 July 2017, 16:57:46 UTC
Run kvm-unit-tests/eventinj.flat in L1 w/ ept=0 on both L0 and L1: Before NMI IRET test Sending NMI to self NMI isr running stack 0x461000 Sending nested NMI to self After nested NMI to self Nested NMI isr running rip=40038e After iret After NMI to self FAIL: NMI Commit 4c4a6f790ee862 (KVM: nVMX: track NMI blocking state separately for each VMCS) tracks NMI blocking state separately for vmcs01 and vmcs02. However it is not enough: - The L2 (kvm-unit-tests/eventinj.flat) generates NMI that will fault on IRET, so the L2 can generate #PF which can be intercepted by L0. - L0 walks L1's guest page table and sees the mapping is invalid, it resumes the L1 guest and injects the #PF into L1. At this point the vmcs02 has nmi_known_unmasked=true. - L1 sets set bit 3 (blocking by NMI) in the interruptibility-state field of vmcs12 (and fixes the shadow page table) before resuming L2 guest. - L1 executes VMRESUME to resume L2, causing a vmexit to L0 - during VMRESUME emulation, prepare_vmcs02 sets bit 3 in the interruptibility-state field of vmcs02, but nmi_known_unmasked is still true. - L2 immediately exits to L0 with another page fault, because L0 still has not updated the NGVA->HPA page tables. However, nmi_known_unmasked is true so vmx_recover_nmi_blocking does not do anything. The fix is to update nmi_known_unmasked when preparing vmcs02 from vmcs12. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Tip revision: 2d6144e366fb39609aecf7a658e2e10af37627e9 authored by Wanpeng Li on 25 July 2017, 10:40:46 UTC
KVM: nVMX: Fix loss of L2's NMI blocking state
KVM: nVMX: Fix loss of L2's NMI blocking state
Tip revision: 2d6144e
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arch | ||
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certs | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 31 bytes |
.gitattributes | -rw-r--r-- | 30 bytes |
.gitignore | -rw-r--r-- | 1.3 KB |
.mailmap | -rw-r--r-- | 8.1 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 96.2 KB |
Kbuild | -rw-r--r-- | 2.2 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 410.5 KB |
Makefile | -rw-r--r-- | 58.8 KB |
README | -rw-r--r-- | 722 bytes |
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