mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-03 07:38:10 +00:00
0e0a53c551
The quote from the comment almost says it all: we are currently zeroing the guest dr6 in kvm_arch_vcpu_put, because do_debug expects it. However, the host %dr6 is either: - zero because the guest hasn't run after kvm_arch_vcpu_load - written from vcpu->arch.dr6 by vcpu_enter_guest - written by the guest and copied to vcpu->arch.dr6 by ->sync_dirty_debug_regs(). Therefore, we can skip the write if vcpu->arch.dr6 is already zero. We may do extra useless writes if vcpu->arch.dr6 is nonzero but the guest hasn't run; however that is less important for performance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
||
---|---|---|
.. | ||
boot | ||
configs | ||
crypto | ||
entry | ||
events | ||
hyperv | ||
ia32 | ||
include | ||
kernel | ||
kvm | ||
lib | ||
math-emu | ||
mm | ||
net | ||
oprofile | ||
pci | ||
platform | ||
power | ||
purgatory | ||
ras | ||
realmode | ||
tools | ||
um | ||
video | ||
xen | ||
.gitignore | ||
Kbuild | ||
Kconfig | ||
Kconfig.cpu | ||
Kconfig.debug | ||
Makefile | ||
Makefile.um | ||
Makefile_32.cpu |