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author | 2021-08-10 06:07:06 -0400 | |
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committer | 2021-08-13 03:35:14 -0400 | |
commit | 375e28ffc0cf4fc48862c03994ec4a93254cf1c6 (patch) | |
tree | d287cf8d58a7f66455f89a67a102abb6e41cff62 /virt/kvm | |
parent | KVM: X86: Remove unneeded KVM_DEBUGREG_RELOAD (diff) | |
download | linux-375e28ffc0cf4fc48862c03994ec4a93254cf1c6.tar.gz linux-375e28ffc0cf4fc48862c03994ec4a93254cf1c6.tar.bz2 linux-375e28ffc0cf4fc48862c03994ec4a93254cf1c6.zip |
KVM: X86: Set host DR6 only on VMX and for KVM_DEBUGREG_WONT_EXIT
Commit c77fb5fe6f03 ("KVM: x86: Allow the guest to run with dirty debug
registers") allows the guest accessing to DRs without exiting when
KVM_DEBUGREG_WONT_EXIT and we need to ensure that they are synchronized
on entry to the guest---including DR6 that was not synced before the commit.
But the commit sets the hardware DR6 not only when KVM_DEBUGREG_WONT_EXIT,
but also when KVM_DEBUGREG_BP_ENABLED. The second case is unnecessary
and just leads to a more case which leaks stale DR6 to the host which has
to be resolved by unconditionally reseting DR6 in kvm_arch_vcpu_put().
Even if KVM_DEBUGREG_WONT_EXIT, however, setting the host DR6 only matters
on VMX because SVM always uses the DR6 value from the VMCB. So move this
line to vmx.c and make it conditional on KVM_DEBUGREG_WONT_EXIT.
Reported-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt/kvm')
0 files changed, 0 insertions, 0 deletions