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author | James Hogan <james.hogan@imgtec.com> | 2016-06-09 14:19:14 +0100 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-06-14 11:02:44 +0200 |
commit | 878edf014e29de38c49153aba20273fbc9ae31af (patch) | |
tree | 0ea5871f8a035389da5aa423e72a0a58f2033473 /arch/mips/kernel/traps.c | |
parent | MIPS: KVM: Drop unused hpa0/hpa1 args from function (diff) | |
download | linux-dev-878edf014e29de38c49153aba20273fbc9ae31af.tar.xz linux-dev-878edf014e29de38c49153aba20273fbc9ae31af.zip |
MIPS: KVM: Restore host EBase from ebase variable
The host kernel's exception vector base address is currently saved in
the VCPU structure at creation time, and restored on a guest exit.
However it doesn't change and can already be easily accessed from the
'ebase' variable (arch/mips/kernel/traps.c), so drop the host_ebase
member of kvm_vcpu_arch, export the 'ebase' variable to modules and load
from there instead.
This does result in a single extra instruction (lui) on the guest exit
path, but simplifies the code a bit and removes the redundant storage of
the host exception base address.
Credit for the idea goes to Cavium's VZ KVM implementation.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/mips/kernel/traps.c')
-rw-r--r-- | arch/mips/kernel/traps.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 4a1712b5abdf..66e5820bfdae 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -1859,6 +1859,7 @@ void __noreturn nmi_exception_handler(struct pt_regs *regs) #define VECTORSPACING 0x100 /* for EI/VI mode */ unsigned long ebase; +EXPORT_SYMBOL_GPL(ebase); unsigned long exception_handlers[32]; unsigned long vi_handlers[64]; |